OldFInal

Question 1

two of the three steps are regulated in glycolysis. what are these?

Answer 1

Hexokinase (1st step)

Phosphofructokinase-1 (3rd step)

Question 2

In the first regulated step (1st step), the produce of the reaction glucose 6-phosphate inhibits the enzyme that catalyzes its own formation. What is the reason for this type of regulation

Answer 2

This is feedback inhibtion

• occurs to prevent accumulation of glucose 6-phosphate
• to maintain high levels of glucose if the use of glucose 6-phosphate is inhibited

Question 3

Given the cure for relative velocity vs {Glucose} for the fist enzyme shown. Adding glucose 6-phosphate to the recant will shift the curve how? What if the Michaelis mention behavior instead, draw the curve.

Answer 3

DRAW ON TABLE

-look desktop

Question 4

Glucagon is a hormone secreted by the pancreas in response to low blood glucose levels. Describe at least 3 mechanisms that are induced by glucagon to restore blood glucose to normal levels.

Answer 4

1)Glucagon activates cAMP synthase and cAMP activates PKA, PKA phosphoryltes pyruvate kinase, so last step in glycolysis is inhibited

PKA phosphorylates glycogen phosphorylase and activates it.This induces synthesizing of glucose 1-phosphate from glycogen

Synthesis of glycogen from glucose is inhibited by PKA phosphorylation of glycogen synthase

Question 5

What are two enzymes within the citric acid cycle (after the synthesis of citrate) that are allosterically regulated and whose regulation control the overall oxidation of acetate?

Answer 5

1) Isocitrae dehydrogenase

2) a-ketogluterate dehydrogenase complex

Question 6

List one activator and one inhibitor of isocitrate dehydrogenase

Answer 6

activator: ADP or Ca2+
inhibitor: ATP

Question 7

List one activator and one inhibitor of a-ketogluteral dehydrogenase complex

Answer 7

Activator: Ca2+
Inhibitor: Succinyl-CoA or NADH

Question 8

What can happen to citrate if its further reaction in the citric acid cycle is impeded?

Answer 8

There is a transporter for exporting citrate to the cytosol

-and citrate in the cytosol will be broken down to oxaloacetate and acetyl-CoA production

Question 9

In the mechanism oxidative phosphorylation, what is the most highly reduced metabolite involved in the electron flow involved in complexes II, III, and IV?

Answer 9

Succinate reacting at complex II

Question 10

In the mechanism oxidative phosphorylation, what is the most highly reduced metabolite involved in the electorn flow involved in complex III

Answer 10

FADH2

Question 11

For complex IV, what is the initial reduced metabolite for electron flow and what is the last reduced metabolite?

Answer 11

Cytochrome (c) is initial reduced metabolite

H20 is last reduced metabolite

Question 12

How does the electron flow through complex III contribute to proton-motive force?

Answer 12

There are 4H+ transfered

Question 13

Is the ATP that is synthesized in oxidative phosphorylation in the eukaryotic cell in the correct cellular location for gluceoneogenesis? WHY?

Answer 13

NO the ATP is generated in the mitochondrial matrix. Gluceoneogenesis occurs in the cytosol so there has to be transport of ATP out of the MATRIX

Question 14

In the Photosystem II complex in purple bacteria, what is the initial electron donor after absorbance of a photon and what is the final reduced product of the PSII complex?

Answer 14

1) excited primary pigment

2) FADH2 (reduced)

Question 15

How much H+ transport is there during absorbance of photons in the PSII complex

Answer 15

NO H+ is transported in PSII

Question 16

In The PSII system, what its he reduced product form cytochrome bc1 (complex III) and what is the role in the overall photosynthesis mechanism?

Answer 16

the reduced produce of cytochrome bc is cytc c

its roles it to diffuse to PSII and reduce primary photopigment (P870) back to ground state

Question 17

What is the consequence of the absorbance of two photons in the photosystem II mech, prior to the action of ATP synthase?

Answer 17

consequence is the translocaton of 4H+ to inter membrane space