Chapter 15 - Key Concepts & Review Points

Question 1

Glycolysis involves the breakdown of ____________ to ____________ while using the free energy released in the process to synthesize ________ from ________ and ________.

Answer 1

glucose
pyruvate
ATP
ADP
Pi

Question 2

The 10-reaction sequence of glycolysis is divided into two stages: ____________ and ____________.

Answer 2

energy investment

energy recovery

Question 3

The 10 steps of glycolysis can be described in terms of their ____________, ____________, and ____________.

Answer 3

substrates
products
enzymatic mechanisms

Question 4

Glycolytic enzymes catalyze ____________, ____________, ____________, and ____________.

Answer 4

phosphorylation reactions
isomerizations
carbon-carbon bond cleavage
dehydration

Question 5

ATP is consumed in steps ____ and ____ but regenerated in steps ____ and ____ for a net yield of 2 ATP per glucose.

Answer 5

1 (glucose –> G6P)
3 (F6P –> FBP)
7 (1,3-BPG –> 3PG)
10 (PEP –> pyruvate)

Question 6

For each glucose, 2 NADH are produced in step ____.

Answer 6

6 (GAP –> 1,3-BPG)

Question 7

NADH, a substrate for the GAPDH reaction, must be ____________ for glycolysis to continue.

Answer 7

reoxidized

Question 8

In muscle, pyruvate is reduced to ____________ to regenerate NAD+.

Answer 8

lactate

Question 9

Yeast decarboxylates pyruvate to produce ________ and ________, in a process that requires the cofactor ________.

Answer 9

CO2
ethanol
TPP

Question 10

Enzymes that function with large ____________ free energy changes are candidates for flux-control points.

Answer 10

negative

Question 11

Phosphofructokinase, the major regulatory point for glycolysis in muscle, is allosterically inhibited by ________ and activated by ________ and ________.

Answer 11

ATP
AMP
ADP

Question 12

____________ allows the rate of glycolysis to respond rapidly to changing needs.

Answer 12

substrate cycling

Question 13

the commonly available hextoses ____________, ____________, and ____________ are converted to glycolytic intermediates for further metabolism.

Answer 13

fructose
galactose
manose

Question 14

The pentose phosphate pathway consists of three stages, in which ________ is produced, pentoses undergo isomerization, and glycolytic intermediates are recovered.

Answer 14

NADPH

Question 15

The pentose phosphate pathway provides ________ for reductive biosynthesis and ____________ for nucleotide biosynthesis in the quantities that the cell requires.

Answer 15

NADPH

ribose-5-phosphate