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Flashcards in Metabolism Deck (64)
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1
Q

_____ is the building of complex structures from simpler ones, and requires energy, much
of which is supplied by _____.

A

Anabolism; ATP

2
Q

_____ is the breakdown of complex structures into simpler ones. Much of the energy
released is captured in _____.

A

Catabolism; ATP

3
Q

_____ is the entire set of reactions comprising both anabolism and catabolism.

A

Metabolism

4
Q

Carbohydrate is stored in the body as _____.

A

glycogen

5
Q

_____ is the set of reactions in which the body generates glycogen polymers from
glucose

A

Glycogenesis

6
Q

When glucose is needed by the body as fuel, glycogen is hydrolyzed back to glucose in a
process called _____.

A

glycogenolysis

7
Q

In the _____ or _____, both glycogenolysis and gluconeogenesis result in export of
glucose into the blood; in _____, however, the glucose that is produced cannot leave the
cell.

A

liver; kidneys; muscle

8
Q

Glycolysis occurs in the cell’s _____, and captures some of the energy stored in glucose
or fructose as ATP. It is particularly useful because it does not require oxygen and is
_____.

A

cytoplasm; very fast

9
Q

Draw a simple diagram of glycolysis showing NAD+, NADH, glucose, ADP, Pi, ATP, and
pyruvate, assuming that oxygen is available.

A

Check question 9. couldn’t paste diagram

10
Q

Draw a simple diagram of glycolysis showing NAD+, NADH, glucose, ADP, Pi, ATP, and
pyruvate, assuming that oxygen is NOT available.

A

Check question 10 couldn’t paste diagram

11
Q

If _____, NADH generated during glycolysis is re-oxidized during “oxidative
phosphorylation” and the energy stored in it is _____.

A

oxygen is available; used to

make ATP

12
Q

If _____, NADH generated during glycolysis is re-oxidized by reducing the product of
glycolysis (pyruvate) to lactate and the energy in the NADH is _____.

A

oxygen is NOT available; lost

13
Q

Before it can enter the citric acid cycle, pyruvate must be converted to _____. Pyruvate
has three carbons: _____ has two. The “missing” carbon leaves as _____, and the energy
that is released is captured in _____.

A

acetyl-CoA; acetyl-CoA; CO2
;
NADH

14
Q

When a phosphate is transferred from a molecule to an ADP, the molecule, phosphate
and ADP are _____ in a reaction. The process is called _____.

A

substrates; substrate level

phosphorylation

15
Q

When a phosphate is added to ADP by the action of ATP synthase, which is driven by a
hydrogen ion gradient generated by the _____ of fuels, the process is called _____.

A

oxidation; oxidative

phosphorylation

16
Q

The citric acid cycle occurs in the _____, and its purpose is to finish oxidizing fuels that
were partially oxidized elsewhere in the cell in order to _____.

A

mitochondrial matrix; extract as

much energy as possible

17
Q

The citric acid cycle is often called the _____ cycle.

A

Kreb’s

18
Q

_____ enters the Kreb’s cycle, and _____ is produced. The energy is captured in _____,
a similar molecule called _____, and _____.

A

Acetyl-CoA; CO2; NADH;

FADH2; ATP

19
Q

The electron transport chain is found in the _____.

A

inner mitochondrial membrane

20
Q

Electrons are fed into the electron transport chain by _____ and _____. Their energy is
transferred to a hydrogen ion gradient, and eventually they, and nearby hydrogen ions,
combine with _____ to form _____.

A

NADH; FADH2; oxygen; water

21
Q

The _____ across the mitochondrial inner membrane is used to power ATP synthase: as
_____ flow through the ATP synthase, ATP is made from ADP and Pi.

A

hydrogen ion gradient; hydrogen

ions

22
Q

In the absence of oxygen, _____ ATP molecules can be produced from the oxidation of
glucose or other sugars. Most of glucose’s energy is lost to the cell when _____.

A

only two; lactate is discarded

23
Q

Lactic acid produced by anaerobic glycolysis is transported in the blood to other organs
which can convert it back to _____ so that it can be used in oxidative phosphorylation.

A

pyruvate

24
Q

In the presence of oxygen, up to _____ ATP can be produced, since the glucose can be
completely, instead of partially, oxidized. There is no need to discard lactate.

A

38

25
Q

Fats are stored in the body as _____.

A

triglycerides

26
Q

The first step in fat catabolism is lipolysis, the separation of the _____ and _____ within
the triglycerides.

A

fatty acids; glycerol

27
Q

_____ is a three carbon molecule which can be converted to a glycolytic intermediate;
after release by lipolysis it can be used in _____ to form pyruvate or, in the liver, to build
_____.

A

Glycerol; glycolysis; glucose

28
Q

Within a cell’s _____, fatty acids undergo beta-oxidation, a process in which _____.

A

mitochondria; carbons are
removed two at a time to form
acetyl-CoA

29
Q

In most tissues, acetyl-CoA formed by oxidation of fatty acids is used in _____.

A

the citric acid cycle

30
Q

. In the liver, pyruvate can be produced from _____ or from _____ as well as from glucose.

A

amino acids; lactate

31
Q

. In the liver, pyruvate can be oxidized as fuel in the TCA cycle, or can be _____.

A

used to make glucose in a

process called gluconeogenesis

32
Q

If the liver does not have enough raw materials to make much pyruvate, both
gluconeogenesis and the TCA cycle slow down, and levels of _____ increase.

A

acetyl-CoA from fatty acid

oxidation

33
Q

If the liver has more acetyl-CoA (from fatty acid oxidation) than it does pyruvate, it uses
the extra to make “_____” which the liver secretes into the blood. From there they reach
the many tissues of the body, including the brain, that can _____.

A

ketone bodies; use them as fuel

34
Q

After a(n) _____, blood levels of ‘ketone bodies’ are ~ 0.12 mM.

A

overnight fast

35
Q

After a(n) _____, blood levels of ‘ketone bodies’ are ~ 7 mM.

A

two week fast

36
Q

In _____, blood levels of ‘ketone bodies’ are often ~ 23 mM.

A

diabetic ketoacidosis

37
Q

The production of ‘ketone bodies’ is _____ in healthy individuals even during a fast, and
levels are not allowed to increase enough to _____.

A

tightly regulated; alter the blood’s

pH

38
Q

In diabetic ketoacidosis, production of ‘ketone bodies’ is _____ and blood pH _____. This
leads to coma and death, unless _____ is administered.

A

uncontrolled; falls; insulin

39
Q

Proteins which are no longer needed are _____, and these in turn are catabolized.

A

hydrolyzed to amino acids

40
Q

When an amino acid is to be catabolized, the amino groups are converted to _____ and
then to _____ in the liver.

A

ammonia; urea

41
Q

When an amino acid is to be catabolized, after removal of the amino group, the remaining
“keto acid” is altered to allow it to enter the _____ (the point of entry depends on the
identity of the amino acid).

A

citric acid cycle

42
Q

What the body cannot store, it must metabolize, either using it for energy or converting it
to a storable form. Alcohol, for example, cannot be stored. Such nutrients are called
‘_____.’

A

obligate fuels

43
Q

Alcohol cannot be stored, and an alcoholic drink with a meal results in temporary _____
as the alcohol is used.

A

storage of the macronutrients

ingested in the meal

44
Q

Protein that is not needed for repair or growth is generally _____ or _____.

A

used for energy; converted to

carbohydrates or fat

45
Q

In times of rapid weight gain excess protein is stored as extra muscle, but this process is
so energetically demanding that it occurs only in the presence of _____ and is usually
accompanied by a large fat deposition.

A

very high caloric intakes

46
Q

Adaptations to increased or decreased ratios of fat to carbohydrate occur _____.

A

within days

47
Q

Adaptations to changes in protein intake occurs after _____, and an abrupt
decrease in dietary protein from accustomed levels can lead to a negative nitrogen
balance as required amino acids are _____.

A

weeks; catabolized for fuel

48
Q

_____ is the most easily stored macronutrient, and excess Calories will result in _____
from the extra food being preferentially stored.

A

Fat; fats

49
Q

The major macronutrients and many of their constituents (the non-essential amino acids,
and many types of fatty acids) can be enzymatically altered to _____.

A

convert one to another

50
Q

Most (although not all) nutrient inter-conversions occur in the _____, and this is one of its
primary tasks.

A

liver

51
Q

Because of the amount of water needed to solubilize it, glycogen occupies a great deal of
space and is quite heavy per Calorie stored. Thus, only _____
can be stored.

A

a few days’ worth

52
Q

Once glycogen stores are full, excess carbohydrate is converted into a(n) _____ in a
process called _____.

A

16 carbon saturated fat;

lipogenesis

53
Q

As glycogen stores are depleted, or when protein intake is excessive, the liver, kidney,
and muscles use amino acids, lactic acid, or glycerol from fats to build new glucose from
in a process called _____.

A

gluconeogenesis.

54
Q

For several hours after eating, the body is in an _____ state, during which its needs for
energy and raw materials for anabolic processes are met by _____.

A

absorptive; nutrients being

absorbed by the intestines

55
Q

Once the intestines are empty the body enters the _____ state.

A

post-absorptive

56
Q

During the post-absorptive state, energy needs are met by _____.

A

drawing on stored fuels

57
Q

During the post-absorptive state, raw materials for anabolic processes are obtained by
_____: that is, existing molecules are catabolized and their component parts used to build
new molecules that may be needed.

A

recycling existing molecules

58
Q

_____ is the energy used at rest. In a typical individual, it is a bit more than half of our
daily energy usage.

A

Basal metabolic rate

59
Q

_____ is the basal metabolic rate, plus any energy used to _____ or _____. (The need to
burn energy to digest food is called the thermic effect of food.)

A

Total metabolic rate; digest food;

perform work

60
Q

Muscle tissue, even at rest, is metabolically expensive: the greater its mass, the higher the
_____.

A

basal metabolic rate

61
Q

Muscle adds strength, which allows more work to be performed per _____, and thus an
increase in muscle mass leads to an increase in calories burnt during exercise or work.

A

hour OR minute

62
Q

Metabolic processes generate heat as a(n) _____. This is the source of our body’s
warmth.

A

waste product

63
Q

A precise body temperature is maintained by adjusting _____, _____, _____, and _____.
These events are overseen and controlled by the _____.

A

BMR; surface blood flow; sweat
production; muscle tension
(shivering); hypothalamus

64
Q

Basal metabolic rate is largely controlled by the _____, which among other things alter the
amount of “wasteful” ion transport across cellular membranes.

A

thyroid hormones