CARBOHYDRATES, PROTEINS, AMINO ACIDS AND LIPID METABOLISM

Question 1

In the catabolism of carbohydrates, glycolysis converts glucose into ____ which is then metabolized into ___

Answer 1

pyruvate
acetyl CoA.

Question 2

In the catabolism of lipids, fatty acids are
converted into ___ and then cleaved into many acetyl CoA units

Answer 2

thioesters

Question 3

are usually reassembled into new proteins.

Answer 3

Amino acids

Question 4

The amino groups (NH2) are converted to ___ which is excreted in __

Answer 4

urea
urine

Question 5

catalyzes the addition of a -COO- (carboxylate).

Answer 5

Carboxylase

Question 6

catalyzes the removal of CO2

Answer 6

Decarboxylase

Question 7

catalyzes the removal of 2 H atoms.

Answer 7

Dehydrogenase

Question 8

catalyzes the isomerization of one isomer into another.

Answer 8

Isomerase

Question 9

catalyzes the transfer of a phosphate.

Answer 9

Kinase

Question 10

is a linear, 10-step anaerobic pathway that converts glucose into two molecules of pyruvate.

Answer 10

Glycolysis

Question 11

Steps [1] to [5] comprise the ____ where 2 ATP molecules are hydrolyzed.

Answer 11

energy investment phase,

Question 12

Steps [6] to [10] comprise the _____ , producing 1 NADH and 2 ATPs for each pyruvate formed.

Answer 12

energy-generating phase

Question 13

Step [1] begins with the
____ of
glucose into glucose 6-
phosphate, using an ATP
and a ___ enzyme.

Answer 13

phosphorylation
hexokinase

Question 14

Step [2] __ glucose 6-phosphate to
fructose 6-phosphate
with an ___
enzyme.

Answer 14

isomerization,
phosphohexose isomerase

Question 15

Step [3] is the
___ of
fructose 6-phosphate
into fructose 1,6-
bisphosphate with a
___ enzyme.

Answer 15

phosphorylation,
phosphofructokinase

Question 16

Step [4] ___ the fructose ring into a dihydroxyacetone phosphate and a gleraldehyde 3-phosphate with enzyme__

Answer 16

cleaves, aldolase

Question 17

Step [5] ___the dihydroxyacetone phosphate
into another glyceraldehyde 3-phosphate.

Answer 17

isomerizes, triose phosphate isomerase

Question 18

In step [6] the aldehyde end of the molecule is
___ by a dehydrogenase
enzyme and this produces
___ and ___

Answer 18

oxidized and phosphorylated

1,3-bisphosphoglycerate and NADH

Question 19

In step [7], the ___ onto
an ADP with a kinase enzyme, forming
3-phosphoglycerate and ATP by enzyme __

Answer 19

phosphate group is transferred

phosphoglycerate kinase

Question 20

In step [8], the phosphate group is __ to a
new position in 2-phosphoglycerate by enzyme

Answer 20

isomerized

phosphoglycerate mutase

Question 21

In step [9], ___ form phosphoenolpyruvate by enzyme __

Answer 21

dehydration

enolase

Question 22

In step [10], the ____ to an
ADP, yielding pyruvate and ATP with a
___ enzyme.

Answer 22

phosphate transfer/
pyruvate kinase

Question 23

Overall, the energy-generating phase forms

Answer 23

2NADHs and 4 ATPs.

Question 24

The fate of the 2 pyruvate molecules depends on
__ availability.

Answer 24

O2

Question 25

The 2 NADHs formed are made in the__
and must be transported to the __ to
join the electron transport chain and make ATP.

Answer 25

cytoplasm

mitochondria

Question 26

is obtained by the hydrolysis of the
disaccharide sucrose, found in sugar beets and
sugarcane.

Answer 26

Fructose

Question 27

___ can be converted by muscle or kidney cells into
___ and enter glycolysis at step [3].

Answer 27

fructose/ fructose 6-phosphate

Question 28

it can be converted by the liver to ___ and enter glycolysis at step [6].

Answer 28

glyceraldehyde
3-phosphate

Question 29

is obtained by the hydrolysis of the
disaccharide lactose in milk.

Answer 29

Galactose

Question 30

Galactose is converted into _ and then enters glycolysis in step [2].

Answer 30

glucose 6-phosphate

Question 31

__ is obtained from polysaccharides in
fruits such as cranberries and currants.

Answer 31

Mannose

Question 32

Mannose is converted to __
and it enters glycolysis at step [3].

Answer 32

fructose 6-phosphate,

Question 33

Thus, all the common hexoses enter glycolysis
and are metabolized into ___

Answer 33

pyruvate.

Question 34

___ can be converted into three possible
products depending on the conditions and the
organism.

Answer 34

Pyruvate

Question 35

pyruvate three products

Answer 35

under aerobic
conditions

under anaerobic
conditions

in fermentation by
microorganisms

Question 36

Under __(when O2 is plentiful),
pyruvate is oxidized by in the presence of
coenzyme A to form acetyl CoA.

Answer 36

aerobic conditions

Question 37

The NADH formed needs ___ to return to so without O2 no additional pyruvate can be
oxidized.

Answer 37

O2

Question 38

In ___ (when O2 is lacking) there is an abundance of NADH.

Answer 38

anaerobic conditions

Question 39

The NADH acts as a ____ reducing
pyruvate to ___

Answer 39

reducing agent,
lactate.