Lecture 7 - Glycolysis Flashcards
Where is glucose entry insulin dependent (i.e. in what cells?)?
adipose tissue, muscle
Glucokinase is found in:
A. Liver B. Pancreatic B cells C. All other cells D. None of these E. More than one of these
E - glucokinase is found in the liver and pancreatic B cells.
Does glucokinase or hexokinase have a lower Km?
Hexokinase (Km = 0.1 mM)
Does glucokinase or hexokinase have a higher Vmax?
Glucokinase
Hexokinase in cells such as the brain and RBCs is always saturated. Only the inhibition of its product, ________, keeps its activity below Vmax.
Glu-6-P
Pancreatic B cells respond to elevated glucose by secreting:
insulin
The role of glycolysis in the ______ is to supply energy for muscle contraction.
muscle
If there is a deficiency in __________ the result is hemolytic anemia.
pyruvate kinase
Glycolytic enzymes are located where?
A. Cytosol
B. Mitochondrial matrix
C. Ribosome
A
Which of the following enzymes is directly used in generating 1 NADH?
A. Hexokinase B. PFK-1 C. Glyceraldehyde-3-dehydrogenase (GAPDH) D. Phosphoglycerate kinase E. Pyruvate kinase
C. The GAPDH enzyme generates 1 NADH (2/glucose molecule).
Which of the following enzymes is directly used in generating 1 ATP?
A. Hexokinase B. PFK-1 C. Glyceraldehyde-3-dehydrogenase (GAPDH) D. Phosphoglycerate kinase E. None of these
D. Phophoglycerate kinase generates 1 ATP (2/glucose).
Which of the following enzymes directly requires 1 ATP?
A. PFK-1
B. Glyceraldehyde-3-dehydrogenase (GAPDH)
C. Phosphoglycerate kinase
D. Pyruvate kinase
A.
Which of the following enzymes is directly used in generating 1 ATP?
A. Hexokinase
B. PFK-1
C. Glyceraldehyde-3-dehydrogenase (GAPDH)
D. Pyruvate kinase
D. Pyruvate kinase is used to generate 1 ATP (2/glucose).
Glyceraldehyde-3-P dehydrogenase (GAPDH) generates an NADH, which must be __________ in order to be reused to continue glycolysis.
oxidized
In aerobic conditions, the ETC and oxygen function to oxidize NADH generated by GAPDH so it can be recycled.
In anaerobic conditions, __________ converts pyruvate to lactate, and oxidizes the NADH back to NAD+ so that glycolysis continues.
lactate dehyrdogenase
Aerobic glycolysis generates 2 pyruvate, 2 NADH, and 2 ATP.
How is anaerobic glycolysis different?
A. No pyruvate generated B. 1 NADH generated C. 1 pyruvate generated D. No NADH generated E. No ATP generated
D - pyruvate is reduced to lactate to regenerate NAD+ so no net NADH production.
______ is the rate-limiting step in glycolysis. It catalyzes the reaction of fru-6-P converted to fru-1,6-BP.
PFK-1
With what mechanism does PFK-1 regulate glycolysis?
Allosteric effectors work by changing the affinity of PFK-1 for the substrate.
PFK-1 is activated by ______ in the liver, which has increased levels with insulin.
A. AMP
B. ADP
C. Fru-2,6-P2
D. Alanine
C. Fru-2,6-P2 is a signaling molecule which has increased levels by insulin and decreased levels by glucagon.
In the liver, pyruvate kinase is covalently regulated by:
A. F-1,6-P2 B. ATP C. ADP D. Alanine E. cAMP-dependent protein kinase
E - cAMP-dependent protein kinase inhibits the action of alanine in the liver.
Glucose-6-P is an intermediate in glycolysis but also in the ______ pathway.
Pentose Phosphate Pathway
