Exam #2: Metabolism

Question 1

The term metabolism is best defined as:

Answer 1

the sum of energy produced by all the chemical reactions the mechanical work of the body

Question 2

The food sources from which we derive energy are composed mainly of:

Answer 2

carbon, hydrogen, nitrogen, and oxygen

Question 3

Carbohydrates are stored in the body as

Answer 3

glycogen

Question 4

Lipid storage is at least 50 times as much (in kcal of energy) as glycogen storage in the body even in a lean adult

Answer 4

true

Question 5

The Tricarboxylic cycle, the citric acid cycle, the Kreb’s cycle are three differing metabolic functions important for producing energy from foodstuffs

Answer 5

False

Question 6

Sucrose —> Glucose + Fructose

The sucrase above is called a(n) _______, and the activity shown in the figure is called _________.

Answer 6

enzyme

hydrolysis

Question 7

Which compound is necessary to transport fatty acids (as acetyl CoA) into the mitochondrial matric, making the use of fatty acids possible as cellular energy sources?

Answer 7

carnitine

Question 8

The electron transport chain resulting from the oxidative system results in _____ ATP from one mole of glycogen, and the resultant total ATP from a mole of glycogen from glycolysis + Kerb’s cycle + the ETC is _____ ATP

Answer 8

34;39

Question 9

Within the mitochondrion, theATP formed along the electron transport chain a created by the process called oxidative phosphorylation

Answer 9

True

Question 10

Which of the following statements is most obviously true regarding the relative roles of fat, carbohydrate, and protein as energy sources for cellular metabolism?

Answer 10

Fat cannot provide all of the energy required for high-intensity muscular activity because the rate of energy release from fat is too slow

Question 11

During maximal, very short-duration exercise, ATP is generated almost exclusively from:

Answer 11

ADP and CrP

Question 12

Fat provides more kilocalories per gram than carbohydrate, but oxidation requirements for fat are greater than oxidation requirements for carbohydrate, making fats less efficient as an energy source per unit of oxygen

Answer 12

True

Question 13

Phosphocreatine is a high-energy phosphate compound that is used in the cell

Answer 13

to resynthesize ATP

Question 14

Before fat can metabolized by the muscle cells, it must be first be broken down into

Answer 14

free fatty acids and glycerol

Question 15

The synthesis of glycogen from glucose is called:

Answer 15

glycogenesis

Question 16

Each human enzyme has an optimal _____ and ______ for it to work most efficiently

Answer 16

temperature and pH

Question 17

Most of the energy for a 2-hour bout of exercise is provided by

Answer 17

the oxidative system

Question 18

Which of the following statements is NOT an accurate description of anaerobic glycolysis

Answer 18

It takes place in the mitochondria of the cell

Question 19

For each liter of oxygen consumed by the body, which substrate provides the greatest number of kcal of energy?

Answer 19

carbohydrate

Question 20

The major metabolic waster product that causes the muscles and blood to have a lower pH during exercise of increasing intensity is:

Answer 20

hydrogen ions

Question 21

Glycolysis takes place in:

Answer 21

the muscle cell cytoplasm

Question 22

Which of the following measurements is necessary when assessing the rate of protein metabolism in the body?

Answer 22

urine nitrogen excretion

Question 23

An important enzyme is involved in one of the simplest and earliest form of the energy systems, called:

Answer 23

creatine kinase

Question 24

NAD and FAD are

Answer 24

coenzymes that transfer hydrogen to the electron transport chain

Question 25

The process of which triglycerides are broken down into glycerol and free fatty acids is called:

Answer 25

lipolysis

Question 26

The process of converting liver or muscle glycogen into glucose-1-phosphate is referred to as glycogenesis

Answer 26

False

Question 27

Beta oxidation is the name for

Answer 27

the process by which free fatty acids are broken down to yield multiple molecules of acetyl CoA

Question 28

The two enzymes most commonly measured in order to assess the oxidative capacity of muscle tissues are:

Answer 28

succinate dehydrogenase and citrate synthase

Question 29

Fast-twitch muscle fibers are best suited for glycolytic energy production

Answer 29

True

Question 30

During near-maximal exercise, significant amounts of lactic acid are generated by the ATP-PCr energy system

Answer 30

False

Question 31

The respiratory exchange ratio (RER) is defined as the ratio between the:

Answer 31

amount of CO2 released to the amount of O2 consumed during metabolism

Question 32

The catabolism of lipids for energy during metabolism will result in a RER of:

Answer 32

>1.0

Question 33

An aerobically trained athlete will have a higher RER during exercise of low to medium intensity than a lesser trained, untrained, or an anaerobically trained athlete

Answer 33

False

Question 34

Accumulation of lactate in the blood is determined by the balance between lactate production and lactate clearance

Answer 34

True

Question 35

Which organ would suffer the most if blood glucose levels during exercise were to drop drastically?

Answer 35

brain

Question 36

Which of NOT true of beta oxidation?

Answer 36

It involves the anabolism of fats

Question 37

Why is beta oxidation called "beta"?

Answer 37

Because oxidation of the fatty acyl chain is on the beta carbon and the chain is broken at each beta carbon atom

Question 38

Protein is not used at all for energy production

Answer 38

False

Question 39

Fatty acids are soluble in blood

Answer 39

False

Question 40

In order to increase lipid metabolism during exercise, aerobic training causes:

Answer 40

improved transport of FFAs through the sarcolemma

Question 41

Free Fatty Acids with a 18-carbon chain entering beta oxidation will yield:

Answer 41

9 molecules of acetic acid for Kreb's cycle

Question 42

Increased carnitine and carnitine acyl tranferase increases the speed of carbohydrate transport in sacroplasm.

Answer 42

False

Question 43

The Cori cycle

Answer 43

recycles lactate via the blood back through the liver to reform glucose

Question 44

After exercise, metabolism returns to resting state

Answer 44

within hours after the end of exercise

Question 45

Metabolic regulation during rest and exercise is controlled by two systems

Answer 45

neural and endocrine

Question 46

At the beginning of exercise, endogenous local ATP loses a phosphate to produce ADP. The ADP stimulates

Answer 46

enhanced secretions of catecholamines blood flow shifts gluconeogenesis increased enzyme activation

Question 47

Lipids released by lipolysis into the blood stream during exercise are carried by:

Answer 47

albumin

Question 48

The first form of ATP buffering during activity is:

Answer 48

ADP+ADP=ATP+AMP

Question 49

Creatine kinase is needed to resynthesize ATP from ADP by phosphorylation, and is boundto the M line proteins on myosin filaments

Answer 49

True

Question 50

Which two hormones stimulate the enzymes necessary for gluconeogenesis

Answer 50

epinephrine and glucagon

Question 51

Exercise stimulates a glucose transporter to get glucose into the sarcoplasm called:

Answer 51

GLUT4

Question 52

As exercise commences, the release of ____ triggers acceleration of pyruvate oxidation

Answer 52

Ca++

Question 53

Overproduction of ____ in intensely contracting muscles is the largest factor stimulating the shutdown of the Krebs cycle

Answer 53

NADH

Question 54

Extremely high levels of lactate in the blood during exercise indicates:

Answer 54

extreme anaerobic exercise increasing lactate levels beyond threshold that the athlete is "in great anaerobic shape"

Question 55

Anaerobic threshold is defined as:

Answer 55

when blood lactate levels rise noticeable above resting levels

Question 56

Pyruvate's dilemma is:

Answer 56

the fact that pyruvate can follow either an aerobic or anaerobic metabolic rate

Question 57

Prolonged exercise causes greater need for lipid energy, which can result in increased

Answer 57

ketone bodies

Question 58

Hard aerobic training does NOT result in increase of ___ in resting muscle

Answer 58

muscle fibers

Question 59

The end product(s) of Beta oxidation that are funneled into the Kreb's cycle and ETC is (are):

Answer 59

acetyl CoA, FADH, and NADH

Question 60

During exercise, gluconeogenesis in the liver oxaloacetate since dependence of fats (i.e. lack of carbohydrate) and depleted oxaloacetate causes the results of fat metabolism to produce ketone bodies

Answer 60

True

Question 61

"Alactic" ATP Production

Answer 61

Production of ATP through anaerobic pathways WITHOUT the lactate as the product

Question 62

"Lactic" ATP Production

Answer 62

Production of ATP through anaerobic pathways WITH the lactate as the product

Question 63

Glycotic ATP Production

Answer 63

Production of ATP through glycolysis.

Question 64

Oxidative ATP Production

Answer 64

Produces ATP through Kreb's cycle and Electron Transport Chain.

Question 65

Explain why is the function of Cori Cycle so important during exercise?

Answer 65

- Lactate is recycled via blood to the liver to supply additional energy to the muscle - It also gets rid of waste products

Question 66

Explain the implications of the illustrated part of the figure concerning #3 (phosphofructokinase)

Answer 66

Exercise increases glycolytic enzymes as ATP and CP levels decrease and AMP levels increase causing stimulation of phosphofructokinase

Question 67

Explain the implications of the illustrated part of the figure concerning #10 (pyruvate kinase)

Answer 67

Exercise increases glycolytic enzymes as ATP and CP levels decrease and ADP levels increase causing stimulation of Pyruvate kinase