Eukaryotes. The Eukaryotic Cell. Slide 1 / 143 Slide 2 / 143. Slide 4 / 143. Slide 3 / 143. Slide 5 / 143. Slide 6 / 143.

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1 Slide 1 / 143 Slide 2 / 143 Eukaryotes January Slide 3 / 143 Vocabulary lick on each word below to go to the definition. 5' cap exocytosis adhering junction exon alternative splicing extracellular matrix cell junction food vacuole central vacuole fungi chitin gap junction chloroplast glycoprotein chromatin golgi appartus chromatin modifying enzyme histone contractile vacuole hydrolytic enzyme cytoskeleton intermediate filament endocytosis intermembrane space endomembrane system intron endosymbiosis lumen eukaryote lysosome Slide 5 / 143 Slide 4 / 143 Vocabulary lick on each word below to go to the definition. matrix poly- tail microfilament pre-mrn microtubule protist mitochondrion receptor-mediated endocytosis mrn processing RN splicing nuclear envelope rough endoplasmic reticulum nuclear pore smooth endoplasmic reticulum nucleolus stroma nucleosome tight junction nucleus transcription factor organelle transport vesicle peroxisome turgor pressure phagocytosis pinocytosis plasmodesmata Slide 6 / 143 Eukaryotes Unit Topics lick on the topic to go to that section The Eukaryotic ell The Nucleus & Gene Expression The Endomembrane System Energy-onverting Organelles Other Organelles & ell Structures The Eukaryotic ell Return to Table of ontents

2 Slide 7 / 143 ll ells ll cells have 4 things in common. They are surrounded by a plasma membrane (or cell membrane). They contain a semifluid substance called the cytosol/cytoplasm. They contain structures called chromosomes, which carry the cell's genes. They have ribosomes, which assemble amino acids into proteins. Slide 8 / 143 Eukaryotes vs. Prokaryotes There are 3 key differences between prokaryotic and eukaryotic cells. Eukaryotic cells are usually larger than prokaryotic cells. Eukaryotic cells have small compartments inside them call organelles. Most eukaryotes (but not all) are multi-cellular organisms. Slide 9 / 143 1Which is NOT a basic feature of all cells? Slide 9 (nswer) / 143 1Which is NOT a basic feature of all cells? ll cells are surrounded by a plasma membrane. ll cells are surrounded by a plasma membrane. l cells contain a semifluid substance called the cytoplasm. l cells contain a semifluid substance called the cytoplasm. ll cells contain structures called chromosomes, which are contained the nucleus. ll cells contain structures called chromosomes, which are contained the nucleus. ll cells have ribosomes. ll cells have ribosomes. nswer Slide 10 / 143 Slide 11 / 143 Eukaryotic cells are, on average, much larger than prokaryotic cells. The average diameter of most prokaryotic cells is between 1 and 10µm. y contrast, most eukaryotic cells are between 5 to 100µm in diameter. acterium (Prokaryote) ell Size nimal ell (Eukaryote) Surface rea to Volume Ratio t the time when prokaryotic cells were evolving, there were most likely different sizes of cells. cell's efficiency and ability to survive depended on its surface area to volume ratio. The volume of the cell determines the amount of chemical activity it can carry out per unit time. The surface area of the cell determines the amount of substances the cell can take in from the environment and the amount of waste it can release. s a cell grows in size, it's surface area to volume ratio decreases. It performs chemical reactions faster, but it has a harder time getting nutrients in and waste out.

3 Slide 12 / 143 We know that cells need to be small enough so that they have an increased surface area to volume ratio, but be large enough to perform the chemical reactions of metabolism. Most Efficient Limits of ell Size Least Efficient To increase efficiency in the larger cell, eukaryotes evolved many bacterium-sized parts known as organelles. Organelles subdivide the cell into specialized compartments. Slide 13 / 143 Organelles The smaller the cell, the larger its surface area and the smaller its volume. The bigger the cell, the smaller the surface area is compared to its large volume inside. They play many important roles in the cell. Some transport waste to the cell membrane. Others keep the molecules required for specific chemical reactions located within a certain compartment so they do not need to diffuse long distances to be useful. Slide 14 / 143 Organelles Slide 15 / 143 Multicellular Organisms Organelles making up Eukaryotic cells include: Nucleus Vacuoles Lysosomes Smooth Endoplasmic Reticulum Ribosomes Rough Endoplasmic Reticulum Peroxisomes hloroplasts Mitochondria Golgi pparatus Even with organelles, the size of the cell is limited to about 1000µm 3. This is why large organisms must consist of many smaller cells. Slide 16 / 143 iversity of Eukaryotes Protists: The first eukaryotic cells. Protists are single-celled eukaryotes. They range from protozoans to algae. Fungi: These organisms evolved second in time along with plants. Examples include mushrooms, molds, and mildews. Slide 17 / 143 2Which of the following are prokaryotic cells? Plants Fungi acteria nimals Plants: Plants vary in type from the first plants called mosses to the modern flowering plants. nimals : nimals were the last eukaryotes to evolve. nimals range from ancient sponges and hydra to primates.

4 Slide 17 (nswer) / 143 Slide 18 / 143 2Which of the following are prokaryotic cells? Plants Fungi acteria nimals nswer 3 How did eukaryotes solve the problem of small surface area to volume ratio? by remaining the same size as prokaryotes by becoming multicellular organisms by compartmentalizing functions into organelles they haven't solved the problem Slide 18 (nswer) / How did eukaryotes solve the problem of small surface area to volume ratio? by remaining the same size as prokaryotes by becoming multicellular organisms by compartmentalizing functions into organelles they haven't solved the problem nswer Slide 19 / ll eukaryotes are multi-cellular. True False Slide 19 (nswer) / 143 Slide 20 / ll eukaryotes are multi-cellular. True False nswer False The Nucleus & Gene Expression Return to Table of ontents

5 Slide 21 / 143 The Nucleus The defining organelle in eukaryotic cell is the nucleus. The nucleus of the cell contains the N and controls the cell's activities by directing protein synthesis from N. prokaryotes: pro: before karyon: kernel/seed (nucleus) eukaryote: eu: true karyon: kernel/seed (nucleus) Slide 22 / 143 The iological Nucleus The nucleus from chemistry with protons and neutrons is not the same nucleus involved with cells. iological Nucleus The biological nucleus is usually, but not always, in the center of a cell and it is sometimes referred to as the "control center" of the cell. So prokaryote = "before a nucleus" nd eukaryote = "true nucleus" Slide 23 / 143 Inside the Nucleus Slide 24 / Main Functions of the Nucleus The nucleus is enclosed by a double cell membrane structure called the nuclear envelope. The nuclear envelope has many openings called nuclear pores. Nuclear pores help the nucleus "communicate" with other parts of the cell. 1. To keep and contain a safe copy of all chromosomes (N) and pass them on to daughter cells in cell division. 2. To assemble ribosomes (specifically in the nucleolus). 3. To copy N instructions into RN (via transcription). Inside the nucleus is a dense region known as the nucleolus. The nucleolus is where rrn is made and ribosomes are assembled. They then exit through the nuclear pores. Slide 25 / 143 5ells that contain a "true nucleus" and other membrane bound organelles are. Slide 25 (nswer) / 143 5ells that contain a "true nucleus" and other membrane bound organelles are. archaea. archaea. bacteria. eukaryotes. bacteria. eukaryotes. nswer prokaryotes. prokaryotes.

6 Slide 26 / Where is the N of a eukaryote found? Slide 26 (nswer) / Where is the N of a eukaryote found? Nucleus Nucleolus Nucleoid Mitochondria Nucleus Nucleolus Nucleoid Mitochondria nswer Slide 27 / How does the nucleus control the activities of the cell? Slide 27 (nswer) / How does the nucleus control the activities of the cell? y making N. y making N. y directing protein synthesis. y allowing N to leave the nucleus to make proteins. nswer y directing protein synthesis. y allowing N to leave the nucleus to make proteins. y sending instructions to the mitochondria. y sending instructions to the mitochondria. Slide 28 / 143 Many ells = Same N ll cells in a multicellular eukaryote contain the same genome. Every cell has all the genes necessary to make all parts of the organism. Slide 29 / 143 Transcription and Translation ells become specialized by only expressing (turning on) certain genes, a small fraction of all the genes in the genome. Transcription Transcription and translation occur in Eukaryotes the same as in Prokaryotes, but there are extra steps that help regulate expression. These muscle cells and brain cells (neurons) have the same N but they are expressing different genes, that is why their structure and function are so different.

7 Slide 30 / 143 Gene Expression in Prokaryotes Gene expression is regulated using operons that turn genes on and off depending on the chemical environment of the cell. Slide 31 / 143 Gene Expression in Eukaryotes Overview Eukaryotes have much more complex chromosomes that require multiple levels of regulation including: "unpacking" of genes transcription factors RN processing Slide 32 / particular triplet of bases in the template strand of N is GT. The corresponding codon for the mrn transcribed is Slide 32 (nswer) / particular triplet of bases in the template strand of N is GT. The corresponding codon for the mrn transcribed is GT. GT. UG. T. U. UG. T. U. nswer E E U E U Slide 33 / 143 Slide 33 (nswer) / codon 9 codon consists of two nucleotides. consists of two nucleotides. may code for the same amino acid as another codon. consists of discrete amino acid regions. catalyzes RN synthesis. may code for the same amino acid as another codon. nswer consists of discrete amino acid regions. catalyzes RN synthesis. E is found in all eukaryotes, but not in prokaryotes. E is found in all eukaryotes, but not in prokaryotes.

8 Slide 34 / If the triplet codes for the amino acid proline in bacteria, then in plants should code for Slide 34 (nswer) / If the triplet codes for the amino acid proline in bacteria, then in plants should code for leucine. leucine. valine. cystine. valine. cystine. nswer E phenylalanine. phenylalanine. E proline. E proline. Slide 35 / 143 hromosomes Slide 36 / 143 hromatin N is configured into structures called chromosomes. Recall that prokaryotes have one chromosome that is double-stranded and circular. The number of chromosomes a eukaryote has depends on the species. These chromosomes are made up of a complex of tightly coiled N and associated proteins called chromatin. Species hromosome # dders-tongue (a fern) 1440 og 78 Human 46 Rat 42 Pig 38 at 38 Rice 24 Slime Mold 12 Jack Jumper nt 2* *2 for females, 1 for males Source: Wikipedia.com The N is tightly wound around proteins called histones, like thread wrapped on a spool. The combination of eight histones and N is called a nucleosome. Video on how N is packaged Slide 37 / 143 hromatin's Role in Gene Expression When N is packed in chromatin it is not accessible to RN polymerase so transcription can not happen. The main factor in the specialization of cells in multi-cellular organisms is what genes are "unpacked" from the chromatin to be exposed to RN polymerase. ll gene sequences are exposed to RN polymerase Slide 38 / 143 hromatin Modifying Enzymes The genes that need to be expressed are unwound from histones by chromatin modifying enzymes in order to expose their nucleotide sequences. Genes that are unnecessary to a particular cell will remain packed while the neccessary ones are unpacked. Some genes exposed No genes exposed

9 Slide 39 / No two cells in the human body have exactly the same N. True False Slide 39 (nswer) / No two cells in the human body have exactly the same N. True False nswer False Slide 40 / How many spools of N and proteins make a nucleosome? Slide 40 (nswer) / How many spools of N and proteins make a nucleosome? nswer 8 Slide 41 / 143 Transcription Transcription of N into RN occurs in the nucleus of the eukaryotic cell Eukaryotic RN polymerase needs the assistance of proteins called transcription factors to help regulate when a gene is expressed. If all the necessary transcription factors are present for a specific gene, then the gene can be expressed. If any are missing, transcription will not start. There can be thousands of transcription factors in an organism's cells (3,000 in humans). The kind and number of them present in the nucleus at any given time dictate what genes are expressed. Slide 42 / 143 Transcription Factors Transcription factors are proteins that are capable of binding with N. When they bind to areas near the promoter region of the gene they work with RN polymerase to begin the transcription of that gene. They are produced in response to cues from the external environment of the cell. These proteins make the cell capable of turning on genes in response to external stimulus. This is essential to multicellular eukaryotes because it allows the different cells of the organism to communicate and respond to situations in unison. Video on regulated transcription

10 Slide 43 / 143 External Signals Slide 44 / The first step in eukaryotic gene expression is... External signal activates membrane bound protein (receptor) transcription translation RN processing unraveling the gene Signal Receptor Metabolic pathway that produces a specific transcription factor in response to signal. The product enters the nucleus. Nucleus Transcription Factor ell Slide 44 (nswer) / The first step in eukaryotic gene expression is... Slide 45 / Where does transcription occur in eukaryotic cells? transcription translation RN processing unraveling the gene nswer nucleus nucleiod cytoplasm cell membrane Slide 45 (nswer) / Where does transcription occur in eukaryotic cells? nucleus nucleiod cytoplasm cell membrane nswer Slide 46 / Once the N is unwound from the chromatin, which of the following is necessary to begin transcription? RN polymerase ribosome transcription factors both &

11 Slide 46 (nswer) / Once the N is unwound from the chromatin, which of the following is necessary to begin transcription? Slide 47 / Transcribe the following eukaryotic gene sequence: TGTTTGGGT RN polymerase ribosome transcription factors both & nswer TGTTTGGGT TTTTG UUGUUG UUUGUUUGGGU Slide 47 (nswer) / Transcribe the following eukaryotic gene sequence: TGTTTGGGT Slide 48 / 143 mrn Processing TGTTTGGGT TTTTG UUGUUG UUUGUUUGGGU nswer fter Transcription, the transcript is known as pre-mrn. Enzymes in the nucleus modify pre-mrn before the genetic messages are sent to the cytoplasm. This is know mrn processing. uring mrn processing, both ends of the pre-mrn are altered. Some interior sequences of pre-mrn may be cut out, and other parts spliced together. Slide 49 / 143 lteration of mrn Ends The 5`end of the pre-mrn receives a molecule known as a nucleotide (or 5') cap. Slide 50 / 143 lteration of mrn Ends The 3` end of the pre-mrn gets a poly- tail. This tail is series of adenosine () nucleotides. This cap is a modified guanine molecule (the G in, T,, G) pre-mrn 5' cap added UGUUG GUGUUG original pre-mrn UGUUG 3' tail added GUGUUG

12 Slide 51 / 143 lteration of mrn Ends The modifications to the ends of the pre-mrn have several functions: They facilitate the export of mrn from the nucleus to the cytoplasm. They protect mrn from hydrolytic enzymes once it is in the cytoplasm. They help ribosomes attach to the mrn so they can be translated into a protein. Slide 52 / 143 RN Splicing Most eukaryotic genes and their RN transcripts have long noncoding stretches of nucleotides that lie between coding regions. These noncoding regions are called intervening sequences, or introns. The other regions called exons (because they are eventually expressed), are usually translated into amino acid sequences. RN splicing removes introns and joins exons, creating an mrn molecule with a continuous coding sequence. Slide 53 / What are the coding segments of a stretch of eukaryotic N called? Slide 53 (nswer) / What are the coding segments of a stretch of eukaryotic N called? introns exons codons introns exons codons nswer replicons replicons Slide 54 / 143 mrn Processing This is an example of a pre-mrn becoming a final transcript. Slide 55 / 143 lternative RN Splicing Some genes can code more than one kind of polypeptide, depending on which segments are treated as exons during RN splicing. lternative splicing allows the number of different proteins an organism can produce to be much greater than its number of genes.

13 Slide 56 / 143 lternative RN Splicing Slide 57 / Which of the following helps to stabilize mrn by inhibiting its degradation? N sequence TTTGGGTTTGGG Pre-mRN (ap)-uuuggguuuggg-(tail) lternate splices (ap)-uuu UUU -(Tail) OR (ap)-gg G GG-(Tail) Resulting polypeptide (protein) Phe - Lys - Phe - Lys OR Gly - Pro - Gly lternate splicing can dramatically change the length and/or the sequence of the polypeptide chain that will be made E RN polymerase ribosomes 5' cap poly- tail both and Slide 57 (nswer) / 143 Slide 58 / Which of the following helps to stabilize mrn by inhibiting its degradation? 19 transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of 400 amino acids. This is best explained by the fact that RN polymerase many noncoding nucleotides are present in mrn. ribosomes 5' cap poly- tail nswer E there is redundancy and ambiguity in the genetic code. many nucleotides are needed to code for each amino acid. E both and nucleotides break off and are lost during the transcription process. Slide 58 (nswer) / 143 Slide 59 / transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of 400 amino acids. This is best explained by the fact that 20Once transcribed, eukaryotic pre-mrn typically undergoes substantial alteration that includes many noncoding nucleotides are present in mrn. removal of introns. nswer there is redundancy and ambiguity in the genetic code. fusion into circular forms known as plasmids. linkage to histone molecules. many nucleotides are needed to code for each amino acid. union with ribosomes. nucleotides break off and are lost during the transcription process. E fusion with other newly transcribed mrn.

14 Slide 59 (nswer) / Once transcribed, eukaryotic pre-mrn typically undergoes substantial alteration that includes Slide 60 / mutation in which of the following parts of a gene is likely to be most damaging to a cell? removal of introns. intron nswer fusion into circular forms known as plasmids. linkage to histone molecules. exon would be equally damaging. union with ribosomes. E fusion with other newly transcribed mrn. Slide 60 (nswer) / 143 Slide 61 / mutation in which of the following parts of a gene is likely to be most damaging to a cell? 22lternative RN splicing intron exon nswer would be equally damaging. can allow the production of proteins of dramatically different sizes from a single mrn. can allow the production of proteins of dramatically different amino acid sequences from a single mrn. oth can happen Slide 61 (nswer) / 143 Slide 62 / lternative RN splicing Entrance into the ytoplasm can allow the production of proteins of dramatically different sizes from a single mrn. can allow the production of proteins of dramatically different amino acid sequences from a single mrn. oth can happen nswer fter the finalized mrn transcript is complete and correct, the pores in the nuclear envelope allow it to pass to the cytoplasm where it can be translated into proteins by ribosomes. The nuclear pore is a protein structure that controls the traffic flow of the nucleus. Each nuclear pore is made up of hundreds of individual proteins that insure only mrns with proper caps and tails can make it to the cytoplasm.

15 Slide 63 / 143 Slide 64 / 143 egradation of mrn Hydrolytic enzymes in the cytoplasm breakdown mrn molecules. The length of time an mrn suvives in the cytoplasm relates to how much protein is made from it. Longer time in the cytoplasm means more translation by ribosomes. The length of the poly- tail is one of many factors that determines the time of survival in the cytoplasm. The longer the tail, the longer it's survival. 23 What is the importance of nuclear pores? They allow the nucleus to communicate with other parts of the cell. They allow N to leave the nucleus in order to direct protein synthesis. They allow RN to leave the nucleus in order to be translated in the cytoplasm. They allow single stranded N molecules to enter the nucleus and assemble into the double helix. Slide 64 (nswer) / What is the importance of nuclear pores? They allow the nucleus to communicate with other parts of the cell. They allow N to leave the nucleus in order to direct protein synthesis. nswer They allow RN to leave the nucleus in order to be translated in the cytoplasm. They allow single stranded N molecules to enter the nucleus and assemble into the double helix. Slide 65 / 143 Summary of Gene Expression Regulation in Eukaryotes The gene must be unpacked from chromatin The right transcription factors must be present Transcription occurs ap and tail must be added to the mrn Pre-mRN must be edited (spliced) Nuclear pores allow passage to the cytoplasm mrn comes into contact with a ribosome Translation occurs Protein is used within the cell or exported to the environment Slide 66 / 143 Slide 67 / 143 The Endomembrane System Endomembrane System Several organelles, some made up mainly of membranes, form a type of assembly line in the cell. They make a protein, then process and ship it to its final destination whether that be inside or outside the cell. Organelles included in this system include the nucleus, rough and smooth endoplasmic reticulum, golgi appartus, and lysosomes. ollectively, we refer to them as the endomembrane system. Note: The plasma membrane is also considered part of this system Return to Table of ontents

16 Slide 68 / 143 The Endomembrane System Slide 69 / 143 Endoplasmic Reticulum When RN leaves the nucleus, it enters the endoplasmic reticulum (ER). This organelle is a series of membrane-bound sacs and tubules. It is continuous with the outer membrane of the nuclear envelope (reticulum comes from the latin word for little net). There are two types of endoplasmic reticulum: rough and smooth. Slide 70 / 143 Rough Endoplasmic Reticulum Slide 71 / 143 Ribosomes Rough ER has ribosomes attached to its membrane (thus a rough appearance). These ribosomes synthesize proteins that will be used in the plasma membrane, secreted outside the cell or shipped to another organelle called a lysosome. s proteins are made by the ribosomes, they enter the lumen (opening) of the ER where they are folded and processed. Recall that the ribosome is made of rrn and proteins. This is where translation occurs. Ribosomes consist of two subunits, a small and a large. Each subunit consists of proteins and rrn. The two subunits come together when proteins need to be made. Small subunit Large subunit Slide 72 / 143 Ribosomes Slide 73 / Where are ribosomal subunits made in the cell? Recall ribosomes make peptide bonds between amino acids in translation. The instructions for making ribosomes are in the N. From N, rrn is made. Some of the rrn is structural and other rrn holds the code from the N to make the ribosomal proteins from mrn. transcription translation N mrn Protein ytoplasm Nucleus Nucleolus On the Plasma membrane

17 Slide 73 (nswer) / Where are ribosomal subunits made in the cell? 25 What do ribosomes consist of? Slide 74 / 143 ytoplasm proteins and N Nucleus proteins and rrn Nucleolus proteins only nswer On the Plasma membrane N only 25 What do ribosomes consist of? Slide 74 (nswer) / 143 Slide 75 / List all the parts of the endomembrane system. proteins and N proteins and rrn proteins only N only nswer rough and smooth endoplasmic reticulum, golgi appartus, lysosomes nucleus, rough and smooth endoplasmic reticulum, golgi appartus, lysosomes nucleus, rough and smooth endoplasmic reticulum, golgi appartus nucleus, rough and smooth endoplasmic reticulum, golgi appartus, lysosomes, plasma membrane Slide 75 (nswer) / List all the parts of the endomembrane system. rough and smooth endoplasmic reticulum, golgi appartus, lysosomes nucleus, rough and smooth endoplasmic reticulum, golgi appartus, lysosomes nucleus, rough and smooth endoplasmic reticulum, golgi appartus nswer nucleus, rough and smooth endoplasmic reticulum, golgi appartus, lysosomes, plasma membrane Slide 76 / Which of the following is involved in making proteins? Smooth E.R. Ribosomes N Nuclear membrane

18 Slide 76 (nswer) / Which of the following is involved in making proteins? Smooth E.R. Ribosomes N nswer Nuclear membrane Slide 77 / 143 Smooth Endoplasmic Reticulum This type of ER is called Smooth because it lacks ribosomes on its surface. (it looks smooth compared to rough ER) There are a variety of functions of this organelle, which include: making lipids. processing certain drugs and poisons absorbed by the cell. storing calcium ions (for example, in muscle cells). Note: The liver is an organ that detoxifies substances that are brought into the body. Therefore, liver cells have huge amounts of Smooth ER. Slide 78 / 143 Protein Transport Once the proteins are processed, short chains of sugars are sometimes linked to these proteins, which are then known as glycoproteins. These glycoproteins serve as "zip codes" that will tell the protein where it will go. When the molecule is ready to be exported out of the ER, it gets packaged into a transport vesicle. This vesicle is made of membranes from the ER itself. The transport vesicle travels to another organelle known as the Golgi apparatus. Slide 79 / The endomembrane system serves to ship cell products to places in and out of the cell assemble N give directions to other organelles create pathways for organelles to travel Slide 79 (nswer) / The endomembrane system serves to ship cell products to places in and out of the cell assemble N nswer give directions to other organelles create pathways for organelles to travel Slide 80 / What determines if we classify endoplasmic reticulum as smooth or rough? presence or absence of nuclear pores presence or absence of genetic material presence or absence of ribosomes presence of absence of N

19 Slide 80 (nswer) / What determines if we classify endoplasmic reticulum as smooth or rough? presence or absence of nuclear pores presence or absence of genetic material nswer presence or absence of ribosomes presence of absence of N Slide 81 / Where in the cell are lipids made? Nucleus Ribosomes Rough endoplasmic reticulum Smooth endoplasmic reticulum Slide 81 (nswer) / 143 Slide 82 / Where in the cell are lipids made? Nucleus Ribosomes nswer Rough endoplasmic reticulum Smooth endoplasmic reticulum The main function of this organelle is to finish, sort, and ship cell products. It works like the postal department of the cell. Golgi pparatus Structurally, the golgi consists of stacked flattened sacs (sort of looks like a stack of pita bread). Slide 83 / 143 Golgi pparatus The Golgi is located near the cell membrane. The Golgi works closely with the ER of a cell. It receives and modifies substances manufactured by the ER. Once the substances are modified, they are shipped out to other areas of the cell. One key difference between the Golgi apparatus and endoplasmic reticulum is that the sacs comprising the Golgi are not interconnected. Slide 84 / 143 The Golgi pparatus & the ER The Golgi receives transport vesicles that bud off from the ER and contain proteins. It takes the substances contained in these vesicles and modifies them chemically in order to mark them and sort them into different batches depending on their destination. The finished products are then packaged into new transport vesicles which will then move to lysosomes, or will be inserted into the plasma membrane or dumped out of the cell if the protein is a secretory protein. Video on Protein Trafficking through the Golgi

20 Slide 85 / difference between the Golgi pparatus and the ER is that Slide 85 (nswer) / difference between the Golgi pparatus and the ER is that The ER takes the vesicles from the Golgi to transport The ER takes the vesicles from the Golgi to transport The sacs making the Golgi are not interconnected The Golgi has ribosomes, the ER does not The sacs making the Golgi are not interconnected The Golgi has ribosomes, the ER does not nswer There is no difference, they are part of the same organelle There is no difference, they are part of the same organelle Slide 86 / 143 Slide 86 (nswer) / Which organelle receives and modifies substances from the endoplasmic reticulum? 32 Which organelle receives and modifies substances from the endoplasmic reticulum? Nucleus Ribosomes Lysosomes Nucleus Ribosomes Lysosomes nswer Golgi odies Golgi odies Some proteins from the Golgi pparatus are transported to the lysosomes. s the name suggests, a lysosome is an organelle that breaks down other substances. (lyse: to cause destruction) They consist of hydrolytic enzymes enclosed within a membrane. Hydrolytic enzymes break polymers into monomers through hydrolysis. Slide 87 / 143 Lysosomes Slide 88 / 143 Lysosomes Lysosomes may fuse with food-containing organelles called vacuoles and then the enzymes digest the food, releasing nutrients into the cell. Protists do this. amaged or unneeded proteins may become enclosed within a membranous vesicle which then fuses with a lysosome. The organic molecules from the breakdown process are recycled and reused by the cell.

21 Slide 89 / 143 Peroxisomes peroxisome is a specific type of lysosome that forms and breaks down hydrogen peroxide (H2O2) which is toxic to cells. In all cells, hydrogen peroxide forms constantly (from the combining of hydrogen and oxygen as bi-products of metabolism) and needs to be broken down quickly. Slide 90 / Which organelle contains hydrolytic enzymes that break down other substances? Endoplasmic Reticulum Golgi odies Lysosomes Vacuoles Important note: Peroxisomes are not part of the endomembrane system. Slide 90 (nswer) / Which organelle contains hydrolytic enzymes that break down other substances? Endoplasmic Reticulum Golgi odies Lysosomes Vacuoles nswer Slide 91 / Which is not a function of lysosomes? aiding the cell in creating ribosomes fusing with vacuoles to digest food breaking polymers into monomers recycling worn out cell parts Slide 91 (nswer) / Which is not a function of lysosomes? aiding the cell in creating ribosomes Slide 92 / 143 Plasma Membrane Remember the plasma membrane is a phospholipid bilayer with proteins and other molecules interspersed throughout. fusing with vacuoles to digest food nswer breaking polymers into monomers recycling worn out cell parts Some proteins from the Golgi pparatus become embedded in the membrane. Others are transported through the membrane to the external environment.

22 Slide 93 / 143 Plasma Membrane The 3 main functions of the plasma membrane: Selective Permeability Protection Structural support Passive transport is the movement of substances from an area of high concentration to an area of low concentration without the requirement an energy input. Types include diffusion, osmosis, and facilitated diffusion. Slide 94 / 143 Membrane Transport - Review Passive Transport ctive Transport (REQUIRES ENERGY) ctive transport is the movement of substances from an area of low concentration to an area of high concentration and requires an input of energy. Slide 95 / Which of the following statements about the role of phospholipids in forming membranes is correct? Slide 95 (nswer) / Which of the following statements about the role of phospholipids in forming membranes is correct? they are completely insoluble in water they are completely insoluble in water they form a single sheet in water they form a structure in which the hydrophobic portion faces outward they form a single sheet in water nswer they form a structure in which the hydrophobic portion faces outward they form a selectively permeable structure they form a selectively permeable structure Slide 96 / 143 Slide 96 (nswer) / ctive transport moves molecules 36 ctive transport moves molecules with their concentration gradients without the use of energy with their concentration gradients without the use of energy with their concentration gradients using energy with their concentration gradients using energy against their concentration gradients without the use of energy against their concentration gradients without the use of energy against their concentration gradients using energy against their concentration gradients using energy nswer

23 Slide 97 / Which of the following processes includes all others? Slide 97 (nswer) / Which of the following processes includes all others? passive transport passive transport facilitated diffusion facilitated diffusion diffusion of a solute across a membrane osmosis diffusion of a solute across a membrane osmosis nswer Slide 98 / 143 Slide 99 / 143 Large Molecules and the Plasma Membrane Many proteins created by the cell are too large to pass through the membrane, even using protein carrier or integral proteins. How do these macromolecules exit the cell? When the substance needs other ways of getting into or out of a cell, they will enter and exit by fusing with the cell membrane. There are several special functions of the membrane as larger substances enter and exit the cell. To excrete a macromolecule from the cell, the vesicles that enclose the proteins fuse with the plasma membrane and the vesicles then open up and spill their contents outside of the cell. This process is known as exocytosis. The vesicle will become part of the cell membrane. Exocytosis Exocytosis This is how secretory proteins from the Golgi exit the cell. This is true for insulin in the pancreas. Slide 100 / 143 Insulin - Secretory Protein Slide 101 / 143 Endocytosis Insulin is a protein hormone made by certain cells of the pancreas that enable cells to take glucose (sugar) in from the blood. Insulin is a secretory protein made in the rough ER. Specifically, it is secreted out of the pancreas cells into the blood stream. The opposite of exocytosis is endocytosis. In this process, the cell takes in macromolecules or other particles by forming vesicles or vacuoles from its plasma membrane. This is how many protists ingest food particles

24 Slide 102 / Types of Endocytosis Slide 103 / Types of Endocytosis Phagocytosis Is for taking in solid particles. ("phago" mean to eat) Pinocytosis Is for taking in liquids. However what the cell wants is not the liquid itself, but the substances that are dissolved in the liquid. ("pino" means to drink) Receptor-mediated endocytosis requires the help of a protein coat and receptor on the membrane to get through. Slide 104 / The process by which a cell ingests large solid particles, therefore it is known as "cell eating". Slide 104 (nswer) / The process by which a cell ingests large solid particles, therefore it is known as "cell eating". Pinocytosis Phagocytosis Exocytosis Pinocytosis Phagocytosis Exocytosis nswer Osmoregulation Osmoregulation Slide 105 / Protein coated vesicles move through the plasma membrane via this process: Slide 105 (nswer) / Protein coated vesicles move through the plasma membrane via this process: Phagocytosis Phagocytosis ctive Transport Receptor-Mediated Endocytosis ctive Transport nswer Receptor-Mediated Endocytosis Pinocytosis Pinocytosis

25 Slide 106 / fter a vesicle empties its contents outside a cell, the vesicle becomes part of: Slide 106 (nswer) / fter a vesicle empties its contents outside a cell, the vesicle becomes part of: the Golgi the Golgi the plasma membrane another vesicle the plasma membrane another vesicle nswer the extracellular fluid the extracellular fluid Slide 107 / 143 Slide 108 / 143 Energy-onverting Organelles Energy-onverting Organelles hloroplasts reside in plant cells and some protists and convert solar radiation into energy stored in the cell for later use. Mitochondria reside in all eukaryotic cells and convert chemical energy from glucose into TP. Interestingly, both chloroplasts and mitochondria have their own N, separate from that found in the nucleus of the cell. They also have a double cell membrane. Return to Table of ontents Slide 109 / 143 hloroplasts Slide 110 / 143 Thylakoids These organelles convert solar energy to chemical energy through photosynthesis. hloroplasts are partitioned into three major compartments by internal membranes: Thylakoids Stroma Intermembrane space eukaryotic chloroplast Remember that during photosynthesis it is on the thylakoid that the Light ependent Reactions take place. In prokaryotes, thylakoids are areas of highly folded membranes. eukaryotic chloroplast In eukaryotes, they are stacked in the chloroplasts. The fluid outside these stacks of thylakoids is called the stroma; this is where the alvin cycle takes place.

26 Mitochondria are sometimes referred to as the "powerhouses" of the cell. They convert chemical energy (glucose) into a more usable and regenerative form of chemical energy (TP). Slide 111 / 143 Mitochondria The mitochondria is also partitioned like the chloroplast. They only have two compartments as opposed to three in the chloroplast. Matrix Slide 112 / 143 Mitochondria and Respiration Remember cell respiration must take place near a membrane so that a proton gradient can be built in a "membrane space" that is separate from the rest of the cell. Thus, the membrane would separate the inner volume, with a deficit of protons, from the outside, with an excess. In prokaryotes, the "inter-membrane space" is between the cell membrane and the cell wall. In eukaryotes, that membrane is the inter-membrane space of the mitochondria in between the inner membrane and outer membrane. Intermembrane space Slide 113 / 143 The Evolution of Eukaryotes Slide 114 / 143 Endosymbiotic Theory The mitochondria and chloroplast are different from other eukaryotic organelles because they have their own N, their own ribosomes, and have a double cell membrane. In 1970, Lynn Margulis published the "Theory of Endosymbiosis" to explain these facts. The theory states that the mitochondria and chloroplast were once free-living prokaryotes that got taken up (or "eaten") by another prokaryote. The mitochondria was a bacteria that could make its own TP. The chloroplast was a bacteria that could perform photosynthesis. endo: within bio: life sym: together sis: condition endosymbiosis = living together, within When they got taken up by another prokaryote, they dragged the one prokaryote's cell membrane around theirs, thus the double cell membrane. This now allowed the "new" eukaryote to make its own TP or be able to do photosynthesis and make its own food. Thus the evolution of eukaryotes. Note: The nucleus and flagella could also have the same possible roots although they are not as heavily supported with evidence as the mitochondria and chloroplast. Slide 115 / 143 Evidence for Symbiosis oth mitochondria and chloroplasts can arise only from preexisting mitochondria and chloroplasts. They cannot be form in a cell that lacks them. oth mitochondria and chloroplasts have their own N and it resembles the N of bacteria not the N found in the nucleus oth mitochondrial and chloroplast genomes consist of a single circular molecule of N, just like in prokaryotes. oth mitochondria and chloroplasts have their own proteinsynthesizing machinery, and it more closely resembles that of bacteria than that found in the cytoplasm of eukaryotes. Slide 116 / 143 The Mitochondrial Eve Since mitochondrial N is not in the cell nucleus, it is only passed along from mother to child; animals, including you, inherit your mitochondria from your mother only. This is because the egg from our mothers contained her organelles. (ad's sperm only contains the chromosomes, none of his organelles usually). ll of our organelles we inherited from our mothers. Mitochondrial N is a way to trace maternal heritage through a family or through a species. The "Mitochondrial Eve" is the first human female that gave rise to all humans. In theory, we can trace all humans back to her through our mitochondrial N.

27 Slide 117 / Which organelle converts food energy into chemical energy that the cell can use? Slide 117 (nswer) / Which organelle converts food energy into chemical energy that the cell can use? Nucleus Nucleus hloroplast Mitochondrion Golgi hloroplast Mitochondrion Golgi nswer Slide 118 / Which organelle converts solar energy into chemical energy in plants and other photosynthetic organisms? Slide 118 (nswer) / Which organelle converts solar energy into chemical energy in plants and other photosynthetic organisms? Nucleus Nucleus hloroplast Mitochondrion hloroplast Mitochondrion nswer Golgi Golgi Slide 119 / Which of the following is not true of mitochondria and chloroplasts? Slide 119 (nswer) / Which of the following is not true of mitochondria and chloroplasts? They are present in all eukaryotic cells They have their own N They have their own ribosomes They are surrounded by a double membrane They are present in all eukaryotic cells They have their own N They have their own ribosomes They are surrounded by a double membrane nswer

28 Slide 120 / Which of the following does NOT provide evidence for the endosymbiotic theory? Slide 120 (nswer) / Which of the following does NOT provide evidence for the endosymbiotic theory? Mitochondria and chloroplasts both have their own N. Mitochondria and chloroplasts both have their own N. Mitochondria and chloroplasts both come from pre-existing mitochondria and chloroplasts. The N of mitochondria and chloroplasts resembles the N found in nuclei. Mitochondria and chloroplasts both come from pre-existing mitochondria and chloroplasts. The N of mitochondria and chloroplasts resembles the N found in nuclei. nswer The N of mitochondria and chloroplasts resembles that of bacteria. The N of mitochondria and chloroplasts resembles that of bacteria. Slide 121 / 143 Slide 122 / 143 Vacuoles Vacuoles are membranous sacs and they come in different shapes and sizes and have a variety of functions. Other Organelles and ellular Structures entral Vacuole Return to Table of ontents PLNT ELL PROTIST Slide 123 / 143 entral Vacuoles entral Vacuoles in plants store water. bsorbing water makes a plant cell more turgid, or having more pressure inside - leading to strength and rigidity. entral vacuoles that are full will take over most of the cytoplasm and literally push the organelles to the sides of the cell. It can also store vital chemicals, pigments and waste products. Slide 124 / 143 Turgor Pressure Increased turgor pressure results from the central vacuole being full with water. It presses out on the cell membrane which then presses out on the cell wall. The plant cell will not explode or lose its shape like an animal cell would in a hypotonic environment. When the turgor pressure decreases the cell is limp and droopy. This is associated with wilted, limp lettuce, as well as droopy flowers.

29 ontractile vacuoles can be found in certain single-celled protists. These act as a pump to expel excess water from the cell. This is especially helpful to those organisms living in a freshwater environment to keep the cell from exploding. Slide 125 / 143 ontractile Vacuoles Food Vacuoles are mainly found in protists. The protist ingests food particles. The particles then fuse with a lysosome. The lysosome contains hydrolytic enzymes that break the food down. Slide 126 / 143 Food Vacuoles Paramecium fed dyed food showing vacuoles. Slide 127 / n organelle found in plant cells that stores water as well as other important substances is called the. Slide 127 (nswer) / n organelle found in plant cells that stores water as well as other important substances is called the. Lysosome Lysosome ontractile Vacuole entral Vacuole ontractile Vacuole entral Vacuole nswer Golgi bodies Golgi bodies Slide 128 / Food vacuoles are primarily found in which organisms? Slide 128 (nswer) / Food vacuoles are primarily found in which organisms? Plants Plants nimals nimals Protists acteria Protists acteria nswer

30 ytoskeleton is a network of fibers within the cytoplasm. Slide 129 / 143 ytoskeleton Slide 130 / ells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. ll of the following are part of the cytoskeleton except Three types of fibers collectively make up the cytoskeleton: Microfilaments Intermediate filaments Microtubules These fibers provide structural support and are also involved in various types of cell movement and motility. the nuclear envelope. microtubules. microfilaments. intermediate filaments. Slide 130 (nswer) / 143 Slide 131 / ells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. ll of the following are part of the cytoskeleton except 48 Which of the following is not a known function of the cytoskeleton? to maintain a critical limit on cell size the nuclear envelope. microtubules. microfilaments. nswer to provide mechanical support to the cell to maintain the characteristic shape of the cell to hold mitochondria and other organelles in place within the cytosol intermediate filaments. Slide 131 (nswer) / Which of the following is not a known function of the cytoskeleton? to maintain a critical limit on cell size nswer to provide mechanical support to the cell to maintain the characteristic shape of the cell to hold mitochondria and other organelles in place within the cytosol Slide 132 / 143 ell wall The cell wall is an outer layer in addition to the plasma membrane, found in fungi, algae, and plant cells. The composition of the cell wall varies among species and even between cells in the same individual. ll cell walls have carbohydrate fibers embedded in a stiff matrix of proteins and other carbohydrates. Plant cell walls are made of the polysaccharide cellulose. Fungal cell walls are made of the polysaccharide chitin.

31 Slide 133 / 143 Extracellular Matrix The cells of many multi-cellular animals are surround by a extracellular matrix (EM). The EM provides structural support to the cells in addition to providing various other functions such as anchorage, cellular healing, separating tissues from one another and regulating cellular communication. Slide 134 / 143 ell Surfaces and Junctions ell surfaces protect, support, and join cells. ells interact with their environments and each other via their surfaces. ells need to pass water, nutrients, hormones, and many, many more substances to one another. djacent cells communicate and pass substances to one another through cell junctions. nimal and plant cells have different types of cell junctions. This is mainly because plants have cell walls and animal cells do not. The EM is primarily composed of an interlocking mesh of proteins and carbohydrates. Slide 135 / 143 Plant ell Junctions Plant cells are supported by rigid cell walls made largely of cellulose. They connect by plasmodesmata which are channels that allow them to share water, food, and chemical messages. Slide 136 / 143 nimal ell Junctions Tight junctions dhering junctions ommunicating (Gap) junctions Slide 137 / 143 Tight Junctions Slide 138 / 143 dhering Junctions Tight junctions can bind cells together into leakproof sheets Example: the cells of the lining of the stomach or any epithelial lining where leaking of substances is not good. tight junction dhering junctions fasten cells together into strong sheets. They are somewhat leakproof. Example: actin is held together in muscle.

32 Slide 139 / 143 ommunicating (Gap) Junctions Gap junctions allow substances to flow from cell to cell. They are totally leaky. They are the equivalent of plasmadesmata in plants. Slide 140 / Which type of junction is found in plant cells? Gap junction Plasmodesmata Tight junction dhering junction Example: important in embryonic development. Nutrients like sugars, amino acids, ions, and other molecules pass through. Slide 140 (nswer) / Which type of junction is found in plant cells? Gap junction Plasmodesmata Tight junction dhering junction nswer Slide 141 / Which type of junction allows for the exchange of materials between animal cells? Gap junction Plasmodesmata Tight junction dhering junction Slide 141 (nswer) / Which type of junction allows for the exchange of materials between animal cells? Slide 142 / 143 Plant vs. nimal ell Organelles Gap junction Plasmodesmata Tight junction dhering junction nswer lick here to review the similarities and difference between plant and animal cells

33 Slide 143 / 143 Organelles in nimal and Plant ells Only Plant oth Only nimal mitochondria golgi apparatus smooth ER central vacuole cell wall rough ER ribosomes lysosomes plasma nucleus membrane chloroplasts