Carbonic anhydrase is an enzyme that catalyzes the interconversion of carbon dioxide and water to bicarbonate and a proton:

CO2 + H2O ? HCO3- + H+

This enzyme is necessary for the reaction shown above to occur rapidly enough for normal kidney function. Which of the following might you expect to occur if we inhibited the carbonic anhydrase present in renal tubular cells?

increased excretion of protons into the lumen of the renal tubule

respiratory alkalosis

metabolic acidosis

Eastern diamondback rattlesnake venom contains high levles of Phospholipase A2, this catalyzes the breakdown of the second of the three (C-2 position) lipid groups of glycerophospholipids. Though the high levels of phospholipase A2 in venom can be deadly, this enzyme is necessary for a variety of normal metabolic processes. What problem(s) does excess of this enzyme cause, by hydrolyzing these bonds? And what are the normal metabolic processes that phospholipase A2 is used for?

In Plant physiology

1. The control of development in plants is more “plastic” (“flexible”) than in animals. Provide one piece of experimental evidence that supports this statement.

2. Glutamate synthetase is central to nitrate assimilation. As a graduate student, you would like to study how this enzyme is regulated by the presences of nitrate in the environment. Describe the design of your experiment that will look at regulation of this enzyme by nitrate. Remember to include controls in your description

11. How do cells transform energy? Consider the first and second law of thermodynamics.

12. Describe the chemical reactions that either release or stores energy. Remembering that energy must be conserved. what do you think happens to the energy we obtain from food during cellular respiration? photosynthesis?

13. What is this energy that drive ALL cellular work? Is it a renewable source?

14. Explain how ATP transfers energy from exergonic to endergonic processes in the cell.

15. How do enzymes function?

16. Are enzymes specific? Why?

17. What is a cofactor? Provide 3 inorganic ions that are cofactors.

18. What is a co-enzyme? Provide an example. Is it organic or inorganic?

19. Enzyme inhibition can regulate enzyme activity in a cell. Explain the benefits of feedback inhibition to a cell.

1) You are a research scientist studying a novel enzyme X, and you want to characterize this new enzyme. You measure the velocity of the reaction with different substrate concentrations and get the following data:

a) Graph the above data. From the graph, estimate KM and Vmax (Michaelis-Menten Plot)

b) Use Lineweaver-Burk plot to calculate Km and Vmax. Show all equations and calculations.

c) You decide to do this experiment again, but this time with only one third of the enzyme X concentration used in the first experiment. Draw a new graph on the same graph that you did the first graph on. Estimate Km and Vmax from the new graph.

Fabry Disease

A 35-year-old man has a history of chronic burning pain in his hands and feet since early childhood. His family history is significant for two maternal uncles who died in their 40’s of renal failure. His mother had a stroke in her 50’s, but is still living. He has just learned that he has Fabry disease and is at very high risk for renal failure, early onset heart disease and stroke. He remembers being told about a enzyme replacement therapy but was too overwhelmed at that time to now recall what he was told. He also wants to know if there are any other options. The scenario described is typical for the presentation of the classical form. There is a less severe variant referred to as the cardiac variant because it is not associated with renal failure.

1. What gene is mutated in Fabry disease and where in the genome is the gene located?
2. Identify the enzyme altered by this mutation and discuss the consequences that result from the impairment of this enzyme.
3. What is the pattern of inheritance for Fabry disease?
4. Discuss some potential therapies, including the enzyme replacement therapies mentioned, as well as any additional options that there may be for this patient.

Answer all

8. As food travels through the digestive tract it will pass through a series of valves and sphincters IN ORDER

a. Lower esophageal spinster; pyloric specter; ileocecal valve; internal and external anal sphincters

b. ileocecal valve; pyloric sphincter; lower esophageal sphincter; internal and external anal sphincters

c. pyloric sphincter; lower esophageal sphincter; ileceal valve; internal and external anal sphincters

d. internal and external anal sphincters; pyloric sphincter; lower esophageal sphincter; ileoceal valve

14. the uvula and epiglottis are present in order to

a. propel food toward the esophagus and stomach during swallowing

b. prevent food from entering respiratory passages during swallowing

c. assist with mechanical digestion in the mouth during chewing

d. increase peristalsis in the esophagus during chewing

15. The primary function of the stomach is ___ made possible due to the presence of ___ a. absorption, villi

b. digestion, parietal cell secretiond

c. food storage, rugae

d. propulsion; smooth muscle

18. Lipid digestion requires the following steps IN ORDER

a. absorption, micelle formation; enzyme digestion, emulsification

b. emulsification; enzyme digestion; micelle formation; absorption

c. enzyme digestion, absorption; emulsification, micelle formation

d. micelle formation; enzyme digestion; emulsification; absorption

28. The binding of a hormone to an intracellular receptor ( inside the cell) would most likely

a. alter a g- protein couple receptor

b. alter a phosphorylation enzyme

c. after a second a messanger

d. alter DNA and start transcription

What are some metabolic diseases caused by amino acid or nucleotide synthesis/degradation mutations?

How can glutamine be used to gain energy? How is amino acid metabolism involved?

13. Describe the type of reaction and the coenzyme required for the first step in amino acid catabolism?