1. Which is true?
  1. Isoenzymes have the same 3D conformation and do different functions
  2. Isoenzymes have different 3D conformations and do different things
  3. Isoenzymes have the same 3D conf. And do the same reaction
  4. Isoenzymes have different 3D conf and do same function

 

  1. Which is true?
  1. Glucokinase has the same affinity for glucose than hexokinase
  2. At a certain concentration of glucose, glucokinase works faster than hexokinase
  3. Glucokinase can only work when the concentration of glc-6-P is low
  4. Hexokinase step can not be reversed by any other enzyme
  5. None

 

  1. Glucose gets in to the tissue cells by
  1. facilitated diffusion
  2. through a carrier
  3. requires NRG in the form of H+ gradient
  4. needs Na+ ions for it to be cotransported
  5. a, b, c
  6. a, b, d
  7. a , b
  8. all

 

  1. Which is true?
  1. all the irreversible steps of glycolysis involve either the production of ATP or the hydrolysis of ATP
  2. all the irreversible steps of glycolysis are regulatory points
  3. all the steps of glycolysis that include ATP production or breakdown are irreversible
  4. glycolysis gives 2 NADH as an end product of the reaction catalysed by glycerate 3 phosphate dehydrogenase
  5. a and c
  6. a and b
  7. a and b and d

 

 

4. Which is True?

a- if we extract some enzymes like Glucokinase from aplha cells of the pancreas and add them to a solution of 5% glucose and 95% glucose-6-P the reaction will occur at 5% of the normal rate

b- the slowest reaction in glycolysis is that catalysed by Hexokinase

c- labeling the NADH from glycolysis will show in the mitochondria only if we label the Nitrogen atom of NADH

  1. Epinephrine also results in the phosphorylation of Gluconeogenic enzymes in a cell that exhibits intercalated disks
  2. none

 

5- Which is True?

  1. Alcoholic fermentation in a Liver cell will produce ethanol and regenerates NAD+
  2. Fermentation cannot be maintained for a long time
  3. Pyruvate is the oxydized form of Lactate
  4. A and B and C
  5. A and C
  6. B and C

 

6- Which isTrue?

  1. Fructose 6-P activates Pyruvate kinase
  2. Fructose 2, 6 bisP activates a phosphatase
  3. F-2,6-bisP is made from F-1,6-bisP by an isomerase
  4. If we isolate the protein enzyme that produces F-2,6- bisP and we isolate the protein enzyme that dephosphorylates it at C2 and subject them to identification we get slightly different peaks in an NMR
  5. A and D

 

7- Which is True?

  1. if PFK 1 is active it means PFK 2 is inactive
  2. if PFK 2 is active it means PFK 1 is inactive
  3. if PFK 1 is active it means PFK 2 is active too
  4. these 2 enzymes are actually one enzyme and do different functions at different domains
  5. c and d

 

8- Which enzyme is regulated by a reversible covalent modification

  1. PFK 1
  2. PFK 2
  3. F-1,6-biphosphatase
  4. F 2,6 bisphosphatase
  5. A and B
  6. A and C
  7. B and D

 

9- Which enzyme is allosterically regulated?

  1. PFK 2
  2. PFK 1
  3. F 2,6- biphosphatase
  4. F-1,6- bisphosphatase
  5. A and B
  6. A and C
  7. B and D
  8. A and B and D

 

 

10- A biopsy was take from an individual and tests were done on the tissues

The lab technician was examining cells that showed a high concentration of lactate dehydrogenase these cells most likely came from

  1. the heart
  2. the lungs
  3. cornea
  4. muscle at rest
  5. cells that produce aldosterone
  6. c and e

 

11- which cells most likely undergo less anaerobic glycolysis

  1. fast twitch muscle fibers
  2. red muscles
  3. RBCs
  4. Cornea cells
  5. B and C and D
  6. A and C and D

 

 

 

Answers: d, e, g, g, f, f, a, c, g, g, c, b

Questions prepared by Michael Nawfal

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