Organism of the Day: Zebra Flatworm

Transcription

1 Organism of the Day: Zebra Flatworm Zebra flatworms are unique because of their ability to excrete ammonia from their body quickly to avoid being poisoned. When animals breakdown proteins, the nitrogenous waste called ammonia is formed. In small doses, ammonia kills cells and can cause human kidneys to fail. Zebra flatworms allow ammonia to diffuse through their skin directly into the water the second proteins are broken down by their intestinal system. 1

2 Biology Thursday/Friday November 15/16, Organism of the Day: Zebra Flatworm 2. Turn in Homework 3. Review Protein Lecture and Explore Enzyme Function 4. Jell O Enzyme Activity 5. Begin Preparing for Upcoming Test Announcements Due Today: Protein Folding Lab Due Monday: Read 2.4 and answer questions 1 3 Unit 2 Test Scheduled for Tuesday/Wednesday next week! Review session Monday, November 19 at 7:50 am. 2

3 Protein Folding 3

4 20 Different Amino Acid 2 major kinds: 1) Hydrophilic: A) Polar B) Charged (+ or ) 2) Hydrophobic 4

5 20 Different Amino Acid 2 major kinds: 1) Hydrophilic: A) Polar B) Charged (+ or ) 2) Hydrophobic 5

6 Amino Acid Chains Primary Structure = amino acids sequence Primary structure varies in Kinds of amino acids Number of amino acids Order of amino acids 6

7 Primary Structure of amino acid leads to hydrogen bonding in the chain. This results in bending/folding = secondary structure Alpha helix Beta pleated sheet 7

8 How a Protein Folds Results in their shape and their function Long = structural proteins, like muscles Globular Cell membrane channels Messengers Cell receptors Oxygen carriers Enzymes 8

9 Everything in life is possible because of reactions! I. Chemical reaction: A. Reactant: B. Product: 9

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11 II. Energy can be defined as the ability. A. Energy releasing reactions are, much like water flowing downhill is spontaneous. 1. Example O 2 + H 2 > H 2 O 2. Energy Sources B. Energy absorbing reactions are, like water flowing is non spontaneous. 11

12 C. Energy of Activation: the amount of energy required to start a chemical reaction. This explains why reactions that release energy may not actually occur, such as a page in a book bursting into flames or a rocket ship exploding before liftoff. 12

13 III. Enzymes: are catalysts that allow reactions to occur much more than they would otherwise occur. A. Enzymes speed chemical reactions by lowering the. B. Example: Carbonic anhydrase catalyses the below reaction. This catalysts speeds the reaction to more than 10 million times! C. Enzymes are very in the reactions that they catalyze. As a result, enzymes are often given names from the. 13

14 D. How do enzymes work? 1. For a chemical reaction to occur: a. molecules must find each other. b. molecules must collide with enough force to break existing bonds. 2. Enzymes bring together substrates (reactants) and stabilize intermediates. 14

15 E. Enzyme Regulation 1. Enzymes play essential roles in: a. Controlling chemical pathways b. Making materials needed for cells c. Releasing energy d. Transferring information 2. Enzymes may be affected by: a. ph b. Temperature c. Salinity d. Regulatory molecules 15

16 Turn and Talk Discuss the question below with your partner for 2 minutes. Be ready to share with the class! 16

17 Enzyme Activity! 1. Work with your lab group. 2. Pick up one dish of Jell O. Write your lab group and period on the 3. Label the bottom as cooked or uncooked pineapple and then add cooked and uncooked pineapple to opposite sides of the dish. Then 4. Record observations in your notes. 5. Place on designated area. I will put your Jell O into the refrigerator. Check back Monday! 17

18 Exit Question: How do enzymes enable reactions to occur faster? Reminders: Unit 2 Test Scheduled for Tuesday/Wednesday next week! Review session Monday, November 19, at 7:50 am. Extra credit opportunity November 17th. See website for ` details. 18