Bellringer: Day Make a list of everything you ate for dinner last night. Categorize each item as either a carbohydrate, fat or protein.

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1 Bellringer: Day Make a list of everything you ate for dinner last night. Categorize each item as either a carbohydrate, fat or protein. 2. Which type of molecule (carbohydrate, fat or protein) is the most important to your diet and why?

2 Cell Structure and Function Unit 02 Biochemistry, Microscopes, Eukaryotes vs. Prokaryotes, Cell Parts, and Unicellular Organisms

3 Organisms contain a number of large, organic molecules. We call these macromolecules. Some examples include: Carbohydrates Lipids Proteins Nucleic Acids Macromolecules

4 Macromolecules Each of the four molecules we will discuss plays and important role in our body. For each, you are responsible for knowing: Structure (building block) Function (what does it do?)

5 Carbohydrates

6 Carbohydrates Carbohydrates are composed of sugar molecules. They can be single, simple sugars or complex sugars. Building block: monosaccharides Function: Energy storage

7 Examples of Carbohydrates Glucose: The main source of energy for organisms. We will be talking about glucose in depth in later units. Cellulose: Makes up cell walls of plants Starch Glycogen

8 Lipids

9 Lipids Lipids are fatty compounds not soluble in water Building block: glycerol and three fatty acids Function: Long term energy storage, insulation, makeup the cell membrane

10 Examples of Lipids: Phospholipids: The lipids that make up the cell membrane. We will be discussing this in depth in a later unit. Steroids Fats/Oils

11 Nucleic Acids

12 Nucleic Acids Nucleic acids are what make up genetic material in our bodies (DNA and RNA) Building block: nucleotides Function: Storing and transmitting genetic information

13 Examples of Nucleic Acids DNA RNA

14 Proteins

15 Proteins Proteins: Chains of amino acids; can be simple chains or complex folded structures Building block: Amino acids Function: Storage, transport, movement, structure, etc.

16 Examples of Proteins Insulin Hemoglobin Enzymes: Speed up chemical reactions in your body

17 Bellringer Day List the four main macromolecules we discussed yesterday. Choose 1 and describe its structure and function.

18 ENZYMES

19 WHAT IS AN ENZYME? Most enzymes are proteins Act as a catalyst to speed up a chemical reaction by helping molecules react with each other faster

20 ENZYMES ARE Reusable! Specific for what they catalyze (speed up) End in -ase Named for the reaction they help. For example Sucrase breaks down sucrose Proteases break down proteins Lipases break down lipids DNA polymerase builds DNA

milk) People lacking the enzyme lactase are considered

21 CASE STUDY: LACTOSE INTOLERANCE Lactase breaks down lactose, a common component of dairy products (like milk) People lacking the enzyme lactase are considered lactose intolerant -they can t digest large amounts of milk!!

22 ENZYMES ARE NOT USED UP! Re-used again for the same reaction with other molecules Very little enzyme is needed to help in many reactions! Substrate Active Site Products Enzyme

23 LOCK AND KEY MODEL Remember, enzymes are specific! Lock and Key Model: Shape of enzyme allows substrate to fit Specific enzyme for each specific reaction Chemical Reaction Enzyme + Substrate Enzyme + Product REACTANTS PRODUCTS

24 SO HOW DO ENZYMES WORK? Enzymes work by weakening bonds, which lowers ACTIVATION ENERGY Activation Energy=energy needed for the chemical reaction to occur (energy needed to activate!) By lowering the activation energy, the reaction can occur faster! Reactions can occur without the help but not at the speed our bodies need!

26 WHAT EFFECTS ENZYME ACTIVITY? Temperature High temperatures can cause enzymes to denature (unfold and lose shape), while low temperatures slow molecules down ph Changes in ph changes protein shape (most human proteins sit at a ph of 6-8) Denaturing=extreme temperature and ph can change enzyme shape, rendering it useless!

27 WHY ARE ENZYMES IMPORTANT? Every reaction in your body is helped by an enzyme. They are necessary for all biological reactions!

28 1. The location where reactants bind to an enzyme during a biochemical reaction is called a) A catalyst b) A product c) A substrate d) An active site 2. How do enzymes speed up biochemical reactions? a) They provide energy to the reactants b) They absorb energy from the products c) They lower the activation energy of the reaction d) They increase the number of available reactant particles

29 Light Microscopes and Total Power Magnification

30 We can use microscopes to observe cells in greater detail Light microscopes are what we will use in class More advanced microscopes, like scanning and electron transmission microscopes, allow us to see prokaryotic and eukaryotic cell differences in greater detail Think about it: How does an electron microscope work? Why are these microscopes so expensive? -A beam of electrons is scanned over a surface to create an image. They are larger, and more expensive to build and maintain!

32 To find this, multiply the power of the objective lens (4X, 10X, 40X), by the power of the eyepiece (usually 10X) Think about it: A student is viewing a slide using an objective lens with a power of 4X. What is the total power magnification? 4 x 10 = 40X

33 Structure and Function of Living Organisms

A cell is the basic structural, functional, and biological unit of all living organisms The building block of life You are made up of about 37 trillion

34 A cell is the basic structural, functional, and biological unit of all living organisms The building block of life You are made up of about 37 trillion cells!!!] Think about it: How do a human and an elephant differ? The elephant has more cells because it is larger, but the cells themselves are not bigger!

35 What do we know about cells?

36 In 1665, Robert Hooke used an early microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers cells.

38 In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells. In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells. These discoveries led to the cell theory.

39 1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells.

40 1. What is a cell? What does cell theory tell us about cells? 2. A student is viewing a microscope with an objective lens of 40x. What is the total power magnification?

41 1. Are all cells the same? Why or why not? Support your answer.

42 Prokaryotic Simple Cells Eukaryotic Complex Cells Plant and Animal Cells

43 Prokaryotic cells are smaller and less complex than eukaryotic cells No membrane bound organelles; smaller Single-celled organisms (ex. Bacteria) Contains: Single, circular DNA; ribosomes; cell membrane

44 Eukaryotic cells are larger, complex cells made up of membrane bound organelles Each organelle within the cell carries out different roles Eukaryotic cells make up complex organisms (mostly multicellular) like insects, fish, and mammals like you!

Additional circular DNA (plasmids) can be present Smaller size EUKARYOTIC Contains

45 PROKARYOTIC No membrane bound organelles (no mitochondria, nucleus, vacuole, or chloroplasts) Ribosomes One strand of circular DNA not enclosed in a nucleus Additional circular DNA (plasmids) can be present Smaller size EUKARYOTIC Contains membrane bound organelles Ribosomes DNA (enclosed by membrane) DNA double-helix strands Larger size

46 Compare and contrast prokaryotic and eukaryotic cells.

47 Animal vs. Plant

48 Animal Cell Nucleus Plasma Membrane Mitochondria Vacuoles Ribosome Cytoplasm Lysosome

49 Plant Cell Nucleus Plasma Membrane Mitochondria Ribosome Cytoplasm Vacuole (large) Chloroplasts Cell Wall

51 The control center Holds the DNA Dark spot inside nucleus is called the nucleolus (it helps makes the ribosomes) Nucleus

52 The powerhouse of the cell It produces most of the energy for the cell Breaks down food to make ATP ATP is major fuel for all cell activities that require energy Folded inner membrane increase the surface area for energy production during respiration Mitochondria

53 Think about it: Which cells would need a lot of mitochondria? Think about it: What would happen if the cell lost all of its mitochondria?

54 The gate of the cell Double membrane structure controls what comes in and out of the cell YOU SHALL NOT PASS (without permission!) Plasma Membrane

55 Protein producer The ribosome makes proteins for the cell Can be attached to the ER or free floating in the cytoplasm Ribosome

56 Storage tanks of the cell It stores food, water, and chemicals in the cell Plant cell vacuole is much larger; controls Turgor Pressure-keeps plant upright (no water=wilting) Vacuole

58 Jelly/gel A liquid/gel like substance that surrounds the organelles Cytoplasm

59 The garbage cans Break down and digest waste products using enzymes Lysosome Think about it: what would happen to the cell if all of the lysosomes burst at the same time? Does this every happen on purpose?

60 Supporter/protector The cell wall shapes and protects the plant cell Think about it: What is the plant cell made of? (Hint: What substance do plants make during photosynthesis?) Cell Wall

61 Food producers They are green Contain green chlorophyll and trap energy from the sun for photosynthesis Glucose (sugar) producers Produce enough ATP to fuel photosynthesis Chloroplast

62 All these organelles work together to keep the cell running!! Think about it: What do you think would happen if The Mitochondria or Chloroplasts stopped working? The Plasma Membrane didn t do its job? The Nucleus stopped directing activities?

64 1. How are prokaryotic and eukaryotic cells similar? a) Both contain a nucleus b) Both contain ribosomes c) Both contain membrane-bound organelles d) Both contain cell walls 2. This diagram shows a plant cell. Which structure is found in a plant cell but absent in an animal cell? a) 1 b) 2 c) 3 d) 4

71 Found only in plant cells, this organelle converts radiant energy to chemical energy through the process of photosynthesis.

72 This organelle is significantly larger in plant cells in order to aid in keeping plants upright. If this organelle is not full, the plant will wilt.

73 The folded inner membranes of this organelle provide more surface area for increased ATP production.

74 These small organelles are vital for the production of proteins in a cell.

75 This organelle controls cell functions and houses DNA.

76 This organelles unique structure allows for the selective passage of molecules into and out of the cell.

77 Nucleus Brain of the cell -controls cell functions and stores DNA Mitochondria Powerhouse of the cell -makes energy through cellular respiration; folded inner membrane provides lots of surface area for cell processes Cell membrane Gate of the cell -Double membrane structure composed of lipids-controls what goes in and out

78 Ribosomes Site of protein synthesis (makes proteins); attached or free floating Cytoplasm Jelly/gel that surrounds cells-keeps organelles where they should be Vacuole Storage center -holds water, food, etc.-large in plants due to Turgor Pressure

79 Chloroplast Plants only-uses sunlight to convert to sugar through process of photosynthesis Cell wall Plants only-carbohydrate called cellulose provides rigid structure that protects and supports cell Lysosome Garbage can -animals only. Uses enzymes to digest waste products

Golgi Apparatus-receives proteins and lipids (fats);

80 Endoplasmic Reticulum-Network of membranes that fold, modify, and transports proteins throughout the cell Golgi Apparatus-receives proteins and lipids (fats); modifies, sorts, and packs them; works closely with the ER

81 Cells all begin as undifferentiated Undifferentiated=not different; the same DNA determines the type of cell (ex. nerve cell, muscle, blood ) We will talk more about this later!

82 Mitochondria? Why? Chloroplasts? Why? Cell organelles can be more concentrated based on needs!

83 ts/science/virtual_labs/e08/e08.html Interactive cell where you match organelle to name and function Quizlet with flashcards, games, and quizzes

84 Decide whether the cell is plant or animal. Next, label the parts with the appropriate name.

85 Structure and Adaptations

86 A multicellular organism is composed of many cells (ex. You are composed of many animal cells; plants are composed of many plant cells) Unicellular means they are composed of a single cell! Ex. Bacteria, protozoa, euglena

87 Unicellular organisms have many structures that help them survive Contractile vacuoles Cilia Flagella Pseudopods Eyespots

88 Stores excess water that enters the cell, and expels it to the exterior It expands when filling with water, then contracts, expelling the contents back out Found in: protists + unicellular algae CKYc

89 A dark area that functions in light reception; influences motion so that the organism can move toward/ away from light Toward (positive phototaxis) Away (negative phototaxis) Found in: green algae; photosynthetic unicellular organisms

90 MysTA Cilia Many hair like structures Often used for movement Non-motile cilia serve as sensory organelles Flagella Single, whip like tail used for movement Found in: bacteria, protists, specialized plant, animal and fungi cells

91 G394 Pseudopods False feet that help the unicellular organism move about Sometimes used to obtain food (phagocytosis)

92 Recall that taxis is an innate behavior in response to an outside stimuli

93 Movement in response to chemicals ( chemo ). Some single celled organisms direct their movement according to chemicals in their environment Found in bacteria and singlecell or multicellular organisms Find food (e.g., glucose) Flee from poisons (e.g., phenol) Critical to early development

94 miqg Movement toward or away from light. Many plant-like unicellular organisms will move toward light to better photosynthesize, just like plants will tilt toward the window Positive phototaxis: if the movement is in the direction of increasing light intensity Negative phototaxis: if the movement is in the opposite direction of light intensity

95 Challenge: Identify the following cells:

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111 Take a few minutes to study!

What is a cell? Recall your work yesterday. When classifying cells, what are the two groups scientists separate cells into?

What is a cell? Recall your work yesterday. When classifying cells, what are the two groups scientists separate cells into? Light Microscopes and Total Power Magnification We can use microscopes to observe