Unit 2: Cells Mr. Nagel Meade High School

Transcription

1 Unit 2: Cells Mr. Nagel Meade High School

2 Warm Up Construct diagrams of: E. Coli Animal Cell (Liver) Plant Cell Indicate which are present in each: Cell wall, plasma membrane, cytoplasm, pili, flagella, ribosomes, nucleoid, rough ER, golgi apparatus, mitochondrion, nucleus.

3 IB Syllabus Statements Compare prokaryotic and eukaryotic cells State that prokaryotic cells divide by binary fission Draw and label a diagram of the ultrastructure of Escherichia coli (E. coli) as an example of a prokaryote Annotate the diagram from with the functions of each named structure Identify structures from in electron micrographs of E. coli Draw and label a diagram of the ultrastructure of a liver cell as an example of an animal cell Annotate the diagram from with the functions of each named structure Identify structures from in electron micrographs of liver cells State three differences between plant and animal cells State that multicellular organisms show emergent properties.

4 Prokaryotes v. Eukaryotes HW: Compare and Contrast with a partner Common structures How do they reproduce? Binary Fission v. Mitosis

5 Prokaryotic Cell (E. Coli)

6 Individual Cells are Either: Round i.e.: staphylococcus Spirial i.e. Spirillum Rod Shaped i.e. Anthrax

7 Prokaryotes in Pictorial Form

8 Up Close and Personal Cell Membrane -Controls passage of materials in and out of cell -Can be infolded (called a mesosome) Cytoplasm -Fluid space where metabolism takes place Ribosome -Freely floating site of protein synthesis NO membrane bound organelles!

9 Some Prokaryotes have a cell wall Gives shape, support and protection to the plasma membrane and cytoplasm of the cell. Made of peptidoglycan* (protein-sugar molecules). *different than plant cell walls, which are made of cellulose

10 Flagellum and Pili Some bacteria have one or more Flagellum. (motility) Pili are short fibers found on some bacteria. (cling)

11 Capsules A special mucus-like protective coating found on some disease-producing bacteria.

12 Gram+ and Gram- Gram-positive bacteria: Stain purple Have a very thick cell wall (because of lots of peptidoglycan). Gram negative bacteria: Stain pink Cell walls only contain a few layers of peptidoglycan Many are pathogenic, meaning they can cause disease in a host organism.

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14 Eukaryotes (Plants and Animals) Discuss with someone next to you differences between plant and animal cells. (Minimum 3)

15 Eukarytoic Cell (Animal)

16 Liver Cell -Nucleolus: Ribosome synthesis -Golgi: Cis Trans Ultrastructure of a liver cell. 1:Nucleolus; 2:Chromatin; 3:Dense Chromatin; 4:Nuclear Pores; 5:Mitochondria; 6:Rough ER; 7:Ribosomes; 8:Golgi Apparatus; 9:Smooth ER;10:Peroxisomes; 11:Lysosomes; 12:Bile Capillary; 13:Desmosomes; 14:Microvilli.

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19 Eukaryotic Cell (Plant)

20 Onion Cell

21 Emergent Properties Quite simply, The whole is greater than the sum of its parts. Imagine a mouse trap. In studying the spring, woodblock, and cheese, you don t necessarily SEE a design for a mousetrap. Placing the items together allows for a whole new level of use for these parts. Applies to multicellular organisms.

22 Research Individually or in pairs, select an organelle. Construct a 6-8 sentence paragraph about: Structure Function Eukaryotic (plant, animal) or Prokaryotic or both Catalogue any subgroups that may be a part Ex: Plastids Chloroplast, chromoplast, amyloplast What would happen to a cell without it?

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24 Warm Up State the cell theory (three parts). Which increases faster as a cell expands: Surface Area or Volume? What does this mean in terms of the survivability of larger cells? Which type of microscope would be best for observing the internal structure of a bacteria?

25 Webquest Cells and Organelles

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27 IB Syllabus Statements Outline two roles of extracellular components Draw and label a diagram to show the structure of membranes Explain how the hydrophobic and hydrophilic properties of phospholipids help to maintain the structure of cell membranes List the functions of membrane proteins Define diffusion and osmosis Explain passive transport across membranes by simple diffusion and facilitated diffusion Explain the role of protein pumps and ATP in active transport across membranes Explain how vesicles are used to transport materials within a cell between the rough endoplasmic reticulum, Golgi apparatus and plasma membrane Describe how the fluidity of the membrane allows it to change shape, break and re-form during endocytosis and exocytosis Outline the stages in the cell cycle, including interphase (G 1, S, G 2 ), mitosis and cytokinesis State that tumours (cancers) are the result of uncontrolled cell division and that these can occur in any organ or tissue State that interphase is an active period in the life of a cell when many metabolic reactions occur, including protein synthesis, DNA replication and an increase in the number of mitochondria and/or chloroplasts Describe the events that occur in the four phases of mitosis (prophase, metaphase, anaphase and telophase) Explain how mitosis produces two genetically identical nuclei State that growth, embryonic development, tissue repair and asexual reproduction involve mitosis Explain that cells in multicellular organisms differentiate to carry out specialized functions by expressing some of their genes but not others State that stem cells retain the capacity to divide and have the ability to differentiate along different pathways Outline one therapeutic use of stem cells.

28 Lipid Bilayer What is the Extracellular Matrix? Support, Adhesion, and Movement Hydrophilic vs. Hydrophobic Fluidic vs. Viscous (unsaturated vs. saturated HC tails) Lateral movement common; layer flip-flop rare Membrane Proteins (Support/Transport)

29 Diffusion and Osmosis Diffusion Molecules moving from higher to lower concentration Osmosis is the diffusion of water molecules Turgor Pressure Water pushing against cell membrane from inside

30 Passive and Active Transport Passive (no Energy) Simple Diffusion Facilitated Diffusion Protein structure helps molecule travel across Gated Channels Separate stimulus opens/closes tunnel Active (ATP) Electrogenic pump (H+) Sucrose-H+ cotransport Na (out) / K (in) pump

31 Transport: Vesicles Exocytosis Secretion of proteins Endocytosis Internalization of materials Phagocytosis (food) Pinocytosis (fluids) Receptor-Mediated endocytosis

32 Consider How does your skin know to grow cells when you get cut, but does not grow when you are undamaged? Do your cells split on a regular basis? How often? What would be the purpose? Could you define the events in the life of a cell?

33 Cell Cycle Interphase G 1, S, and G 2 G = Gap S = Synthesis Mass production! Cancer cells What do you think goes wrong? CDKs (cyclin dependent kinases) ex: p57

34 Mitosis Perfect reproduction (two identical nuclei) Growth, embryonic development, tissue repair, asexual reproduction P.M.A.T.

35 Name That Phase

36 Cell Cycle Project How long does a typical cell spend in each phase of Mitosis/Cell Cycle? Let s consider an onion root tip cell es/cell_cycle/cell_cycle.html

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38 Warm Up What macromolecules are part of the extracellular matrix? What two molecules can pass through the lipid bilayer unhindered? Plant cells prefer tonic conditions, whereas animal cells prefer tonic conditions. The phase of the cell cycle in which DNA is replicated is phase.

39 Cell Cycle Project How long does a typical cell spend in each phase of Mitosis/Cell Cycle? Let s consider an onion root tip cell The average cycle duration is 24 hours. Interphase Prophase Metaphase Anaphase Telophase TOTAL Quantity 36 Percent 100% Time 24 hrs

40 Interesting Thoughts In the human body, the rate of mitosis is believed to be 25 million cells produced every second! That comes out to 2 trillion cells per day! Cells that divide rapidly Skin, Epithelial, Bone Marrow Cells that must be stimulated to divide Liver Cells that do not divide Nerve, Muscle

41 Circle Map Stem Cells

42 Stem Cells and Specialization Cells in multicellular organisms differentiate to carry out specialized functions by expressing some of their genes but not others. Stem cells retain the capacity to divide and have the ability to differentiate along different pathways. There are a variety of levels. There are numerous therapeutic applications of stem cells both currently in use and theorized.

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44 Warm-up Outline the stages in the cell cycle. Outline the events of the four phases of Mitosis. What life processes are evidenced by Mitosis?

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46 Warm-up State three differences between plant and animal cells. Define Diffusion and Osmosis. How can/could stem cells be used therapeutically?