Chemistry 256 Sample exam 2 1. Which of the following statements about Na+-K+ ATPase transport system are true? a. Is considered a carrier ionophore. b. Is a Uniport system. c. Is an active transporter and therefore require hydrolysis of ATP. d. Involves a conformational change of the transporter. e. Transports 4 Na+ ions for every 1 K+ion. f. Is considered a Passive-mediated system. 2. Which statements are is true regarding action potentials/Nerve impulses a. b. c. d. e. Depend upon a concentration gradient of Na+ and K+ ions. Depends on ion channels that are non-selective towards Na+ and K+ ions There is a resting potential across the nerve cell membrane. Both the sodium and potassium ion channels are ‘gated’. The Na+-K+ ATPase transport system is responsible for the membrane potential. 3. What molecules could be considered storage for amino acids. a. b. c. d. e. Carbohydrate Glycogen Proteins Triacylglyderides Urea 4. What is the fate of the amino group when amino acids are degraded and excreted from the body. 5. What is the product of a hydrolysis of a protein 6. Which enzyme can hydrolyze proteins? a. b. c. d. e. Aminotransferease Lysosome Protease ATPase Dehydrogenase 7. In what process is ubiquitin used? Breifly describe it action. 8. What are the fates of amino acids that has been degraded? a. b. c. d. e. The NH3 group is converted to Urea The NH3 group is converted to Acetyl-CoA The carbon skeleton is converted to Glucose The carbon skeleton is converted to Urea The carbon skeleton is converted to Ketone bodies 9. What are the products of the reaction below (transamination) NH3+ - O- CO2- O2C aminotransferase + CH3 O O 10 What process if the PLP enzyme important. Describe its action 11.Below is the Tetrahydrofolate molecule. What is its main function? Circle the nitrogen(s) in this molecule that carryout that function. 12. a. What are major components of light harvesting antenna? a. b. c. d. e. Chlorophyll Carotene Protein THF Urea b. What is the main functionality/functional group of the compounds you choose above that gives rise to their ability to harvest light. 13. During Photosynthesis what event occurs in the OEC? What does it stand for? 14. Which part of the chloroplast do the ‘light reactions’ take place? a. b. c. d. e. Outer membrane Stroma Thylakoid membrane Inner membrane Chloroplast center 15. Which photosynthetic reaction center (PSI or PSII) is responsible for ATP synthesis_________________ NADPH synthesis______________ O2 production.________________ Proton gradient formation________ 16. Which Plastoquinone(ol) shown below is oxidized and which is reduced. 17. Which events take place in the stroma of the chloroplast? a. b. c. d. ATP synthesis, OEC Reduction of NADP Formation of oxygen 18 a. What is photophosphorlation? b. Where does it occur? c. What other process from chem 255 does this mimic? 19. What is the important product of the Calvin cycle that goes on to produce carbohydrates? 20. What 2 reactants do photosystem I and II contribute to the Calvin cycle? 21. Circle what is true regarding the Calvin Cycle Carbon dioxide is fixed GAP is formed Nitrogen is fixed. Acetyl CoA is formed. ADP is produced 22. Which compounds below is an intermediate for the synthesis of starch in plants a. b. c. d. e. ADP-Glucose Ketoglutarate Tetrahydrofolate Pyruvate Glycogen 23. What compound below is Chlorophyll similar to? Hemoglobin Glucose ATP AcCoA Mitochondria 24. When Nitrogen is ‘Fixed’ what is occurring: a. b. c. d. e. Nitrogen is being oxidized to a biologically useful form Nitrogen is being reduced to a biologically useful form Nitrogen from amino acids is being converted to a biologically useful form Nitrogen is being decomposed and excreted to the soil. Nitrogen is being assimilated into Urea. 25. What type of plants fix nitrogen? 26. Is the fixing of nitrogen an exothermic or endothermic process? 27. Which molecule is necessary for the assimilation of nitrogen into amino acids? a. b. c. d. Acetyl Co-A Pyruvate -Ketoglutarate GAP 28 Which Amino acids would you consider to be both Glucogenic and Ketogenic (use chart below)? 29. The biosynthesis of Tyrosine depends upon the hydroxylation of phenylalanine by the enzyme phenylalanine dehydrogenase (PAH) (show below). a. What disease results from the lack of PAH? b. Show the reaction that will occur when phenylalanine cannot be converted to tyrosine. 30. Depict the hydrogen bonding between the base pair Cand G. O H H N N N H N HN NH N O NH2 Guanine 31 Depict the enol form of Guanine base cytosine H 32. Describe ‘translation’ H O N N N HN H N NH N O thymine 33. Describe transcription. adenine