Glycolysis

Question 0

What is GLUT1?

Answer 0

a housekeeping glucose transporter with a low Km

found in all cells including RBCs which depend solely on glucose for fuel

Question 1

what is GLUT5?

Answer 1

a fructose transporter in the liver or small intestines

Question 2

What is GLUT2?

Answer 2

high Km for glucose
presence in liver means liver will take up glucose when blood glucose concentration is raised such as after a meal
allows for the export of glucose from the liver in the fasted state

Question 3

What is GLUT3?

Answer 3

low Km glucose transporter in the brain

Question 4

What is GLUT4?

Answer 4

In adipose and muscle tissues
Insulin dependent translocation to plasma membrane
increases uptake 20 fold

Question 5

What would you expect in a person without GLUT2?

Answer 5

Inability of liver to uptake excess glucose when blood glucose is high
Functioning GLUT2 allows for the export of glucose from liver in the fasted state

Question 6

What links Glycoylosis to other pathways?

Answer 6

Glucose 6 P

Question 7

What is the enzyme in the first committed step of glycolysis?

Answer 7

Phosphofructokinase I

by adding the PO4, the glucose is now trapped inside the cell

Question 8

What is substrate level phosphorylation?

Answer 8

…

Question 9

What does Glycolysis consume?

Answer 9

glucose
2 ADP
2 NAD+
2 Pi

Question 10

What are the products of Glycolysis?

Answer 10

2 pyruvate 
2 ATP 
2 NADH
2 H+ 
2 H20

Question 11

Hexokinase IV

Answer 11

only in liver
works when glucose concentration is high
has very high Km = 10^-2

Question 12

PFK1

Answer 12

metabolically irreversible
critical regulatory point
first committed step of glycolysis

Question 13

PFK2

Answer 13

regulatory molecule for PFK1

Question 14

ATP is a substrate AND ???? for ????

Answer 14

Allosteric inhibitor for PFK1

Question 15

NAD+ is reduced to

Answer 15

NADH

Question 16

What is a site for Arsenic poisoning?

Answer 16

AsO4 can substitute for PO4 creating a futile cycle

Question 17

Under aerobic conditions, what is the fate of pyruvate?

Answer 17

Acetyl CoA

Question 18

Under anaerobic conditions in microorganisms, allows Pyruvate conversion to …

Answer 18

Ethanol

Question 19

Under anaerobic conditions what do our muscles convert pyruvate to?

Answer 19

Lactate

Question 20

what must you recycle to keep glycolysis running?

Answer 20

NADH must be converted back to NAD+ to keep glycolysis running

Question 21

when ATP is needed

Answer 21

glycolysis is activated

Question 22

what inhibits Hexokinase?

Answer 22

excess G6P

Question 23

what ramps up PFK1?

Answer 23

AMP

F26BP

Question 24

what inhibits PFK1?

Answer 24

ATP

citrate

Question 25

What induces Pyruvate kinase ? inhibits?

Answer 25

F1,6 BP - induces

ATP - inhibits

Question 26

What induces Pyruvate dehydrogenase? inhibits?

Answer 26

ADP and Ca+2 - induce

NADH and Acetyl CoA - inhibit

Question 27

what is F 2,6 BP?

Answer 27

allosteric activator of PFK1 that opposes ATP inhibition

synthesized by PFK-2 from F6P
has kinase and phosphatase domain
can be regulated by serine-threonine protein kinases

Question 28

For PFK-2,in skeletal muscle, when a high concentration of F6P is present, this activate the kinase and inhibit the phosphatase thereby

Answer 28

increasing concentration of F2,6 BP and activating glycolysis

Question 29

increased NADH concentration prevents pyruvate oxidation in the TCA cycle and directs …

Answer 29

pyruvate to lactate

Question 30

What is the Pasteur effect?

Answer 30

slowing of glycolysis in the presence of oxygen
more ATP is produced under aerobic conditions than under anaerobic conditions, therefore less glucose is consumed aerobically