Glycolysis and the TCA cycle

Question 1

Key regulatory enzymes of glycolysis

Answer 1

Hexokinase , PFK, Pyruvate kinase

Question 2

Nets of glycoolytic pathway

Answer 2

2 ATP 2 NADH 2 Pyruvate

Question 3

Explain Km and affinity for GLucokinase

Answer 3

high Km , low affinity for glucose .. only uses glucose when glucose levels are very high

Question 4

Increase of G6P means a decrease in

Answer 4

glucokinase

Question 5

Committed step go glycolysis

Answer 5

PFK

Question 6

Two isoforms of pyruvate kinase

Answer 6

Liver isoform - regulated by phosphorylation Muscle - not reg by phos

Question 7

Net yields of the TCA

Answer 7

3 NADH 1 GTP 3 H+ 1 FADH2

Question 8

Key regulation sites at TCA

Answer 8

Citrate synthase Isocitrate dehydrogenase Alpha ketoglutarate dehydrogenase

Question 9

Things that can be turned into Ace COA

Answer 9

AA FA Pyruvate

Question 10

Things that can be turned into OAA

Answer 10

AA Pyruvate , Propionyl COA

Question 11

Things to know about pyruvate dehydrogenase complex

Answer 11

1. requires TPP, lipoid acid, and FA 2. Requires 3 subunits E1 E2 E3 3. Catalyzes the oxidative decarboxylation of pyruvate

Question 12

More efficient shuttle

Answer 12

glycerol phosphate shuttle

Question 13

PFK influenced primary by

Answer 13

energy charge of cell and nutritional status of the liver

Question 14

Activators of glucokinase

Inhibitors

Answer 14

Insulin

Inhibitors: G6P

Question 15

A and I of PFK

Answer 15

A:

AMp,

F2,6-BisP

I:

ATP

Citrate

Question 16

A and I of Pyruvake kinase

Answer 16

A:

AMP,

F1,6-BisP- (earlier intermediate of that pathwasy that tells the cycle to keep up)

I:

ATp, Ace-CoA, Alanine

Question 17

Enzymes def in Hemolytic anemia

Answer 17

Pyruvate kinase (95%)

Phophoglucose isomerase (4%)

Question 18

What feeds into glyc pathway and where ?

Answer 18

GLycerol : at DHAP

GLycogen at G6P

Alanine and lactate at pyruvate

Question 19

Key regulatory enzymes of the TCA

Answer 19

Citrate synthetase

Isocitrate dehydrogenase

Alpha keto glutarate dehydrogenase

Question 20

Where is pyruvate dehydrogenase enzyme located ?

Requires what 3 things

Answer 20

Mito matrix

Tpp

Lipoic acid

FAD

Question 21

Explain CoA, NAD+ , and AMP regarding Pyruvate dehydrogenase complex

Answer 21

All of these activate

“Keep the cycle going and make energy”

Question 22

Ace-CoA, NADH, GTP/ATP regarding pyruvate dehydrogenase complex

Answer 22

Inhibitors

” slow down , we have enough”

Question 23

Explain dephosphorylation and phosphorylation of pyruvate dehydrogenase complex

Answer 23

Dephopshorylation =activation

Phosphorylation =deactivation

Question 24

What effects does pyruvate have on the Pyruvate dehydrogenase complex?

Answer 24

its is the substrate so its activates it

Pyruvate also inhibits the kinase which deactivates the complex, so its like taking the breaks off the car

Question 25

High NADH/NAD+ and high Ace-CoA/CoA levels will do what to pyruvate dehydrogenase complex?

Answer 25

SLow it down "says, we have enough stuff" But these ratios also activate a kinase which in turn inhibits the enzyme

Question 26

What effect does calcium have on the phosphodehydrogenase complex

Answer 26

It activates the phosphotase which activates the complex

Question 27

Given a High NADH and High Ace-CoA ratios , these do what to the pyruvate dehydrogenase complex?

Answer 27

Inhibit the phosphatase , therefore inactivating the complex

Question 28

What inhibits citrate synthase ?

Answer 28

ATP, NADH, and Succinyl Co-A

Question 29

Isocitrate dehydrogenase is inhibited by and activated by?

Answer 29

I: ATP, NADH A: ADP, Calcium

Question 30

Alpha keto glutarate is activated and inhibited by ?

Answer 30

I: ATP, NADH, Succininyl CO-A A: AMP , Calcium

Question 31

In oxidative phosphorylation, the protons are pumped into

Answer 31

intramenbranous space

Question 32

Complexes that pump hydrogen out

Answer 32

1, 3, 4 1 and 3 pump out 4H+ and 4 pumps out 2H+

Question 33

Role of ubiquinone

Question 34

What enzyme is associated with complex 2

Answer 34

Succinate dehydrogenase

Question 35

Oxidizes cytochrome C

Answer 35

Complex 4

Question 36

Explain the cost of ATP synthesis

Answer 36

the matrix has a -4 charg (ATP)and cytosol has a -3 charge (ADP) before ATP goes to cytosol Once ATP is exchanged to cytolsol, charge goes from -3 to -4 ,so inessence that costs 1 proton

Question 37

ATP to NADH and FADH2 ratio

Answer 37

1NADH=2.5 ATP 1FADH2= 1.5 ATP

Question 38

Gives overview of regulating oxidative phosphorylation

Answer 38

muscle uses ATP increase in ADP increase in ATP synthesis decrease in proton gradient increase ETC to restore gradient decrease in NADH/NAD+ and FADH2/FAD ratios increase fuel oxidation

Question 39

Inhibitors of complexes

Answer 39

complex 1: rotenone , Amytal, Demerol, Cyt C- Carbon monoxide , cyanide , azide, ATP synthase - oligomyocin Membrane- uncouplers , 2,4-dinitrophenol, dicumarol, FCCP