Concept 9.2: Glycolysis harvests chemical energy by oxidizing glucose to pyruvate

Question 1

The word glycolysis means

Answer 1

“sugar splitting,”

Question 2

Glucose, a six-carbon sugar, is split into

Answer 2

two three-carbon sugars

Question 3

These smaller sugars are then oxidized and their remaining atoms rearranged to form

Answer 3

two molecules of pyruvate

Question 4

glycolysis can be divided into two phases: the energy investment

Answer 4

phase and the energy payoff phase

Question 5

During the energy investment phase, the cell actually spends

Answer 5

ATP.

Question 6

this investment is repaid with interest during the energy payoff phase, when ATP is produced by substrate-level phosphorylation and is

Answer 6

reduced to NADH by electrons released from the oxidation of glucose.

Question 7

The net energy yield from glycolysis, per glucose molecule, is

Answer 7

2 ATP plus 2 NADH

Question 8

ATP is produced from a molecule of

Answer 8

glucose, our fuel

Question 9

the first step called glycolysis and takes place outside the

Answer 9

mitochondria

Question 10

to begin the process some energy

Answer 10

has to be invested

Question 11

next the molecule is split in

Answer 11

half

Question 12

now the molecule, NAD+ an electron carrier picks up electrons and a hydrogen atom from the carbon molecule becoming

Answer 12

NADH

Question 13

the electron carriers play an important role by

Answer 13

transporting electrons to the mitochondria

Question 14

in the final steps of glycolysis some

Answer 14

ATP is produced but not much

Question 15

for every glucose molecule only two net ATPs are produced outside the

Answer 15

mitochondrion

Question 16

however, glycolysis has produced __________________ which still has a lot of energy available

Answer 16

pyruvic acid

Question 17

no carbon is released as ______ during glycolysis.

Answer 17

CO2

Question 18

if O2 is present, the chemical energy stored in pyruvate and NADH can beextracted by

Answer 18

pyruvate oxidation, the citric acid cycle, and oxidative phosphorylation.