Regulation of Carbohydrate Metabolism and Exercise

Question 1

what systems does exercise involve? (4)

Answer 1

musculoskeletal
respiratory
endocrine
immune

Question 2

what does increased breathing and heart rate provide? (4)

Answer 2

increased O2 and nutrients
eliminates CO2 and metabolic waste products
transport hormones
maintain body temp and acid-base balance

Question 3

in response to demand, muscles (3)

Answer 3

change ability to extract O2
choose energy sources
eliminate metabolic waste

Question 4

what are fast fibers composed of?

Answer 4

type 2 myosin (2a and 2b)

Question 5

what are slow fibers composed of?

Answer 5

type 1 myosin

Question 6

what are the main fiber types? (3)

Answer 6

type 1
type 2a
type 2b

Question 7

what color are type 1 fibers? why?

Answer 7

red, due to large amounts of myoglobin

Question 8

what do slow twitches contain? (2)

Answer 8

large numbers of oxidative enzymes

more mitochondria

Question 9

do slow twitches or fast twitches surround more capillaries?

Answer 9

slow

Question 10

type 1 fibers have a large capacity for

Answer 10

aerobic metabolism

Question 11

type 1 fibers have a high resistance to

Answer 11

fatigue

Question 12

generally, postural muscles are used for

Answer 12

endurance (marathon runners)

Question 13

how do type 1 fibers generate ATP?

Answer 13

aerobic metabolism

Question 14

what are type 2a fast oxidative fibers are a hybrid of

Answer 14

type 1 and type 2

Question 15

what color are type 2a fibers?

Answer 15

red, but not as red as type 1

Question 16

do type 2a fibers perform anaerobic or aerobic metabolism?

Answer 16

both to generate metabolism

contain large numbers of mitochondria

Question 17

type 2b fast glycolic fibers are what color? why?

Answer 17

white, they contain low levels of myoglobin and few mitochondria

Question 18

do type 2b fibers use aerobic or anaerobic metabolism?

Answer 18

anaerobic to generate ATP

Question 19

what can influence muscle composition?

Answer 19

training and genetics

most are a combination of these two types

Question 20

what is type 1 used for?

Answer 20

long distance

slow twitch

Question 21

what is type 2a used for?

Answer 21

400m/800m

fast twitch oxidative

Question 22

what is type 2b used for?

Answer 22

short sprints

fast twitch glycolytic

Question 23

low fatigue to high fatigue

Answer 23

type 1
type 2a
type 2b

Question 24

what does fiber type vary with?

Answer 24

exercise type

Question 25

what do slow twitch fibers vs fast twitch fibers look like under a microscope?

Answer 25

slow: dark fibers fast: white fibers

Question 26

what provides energy during the start of exercise?

Answer 26

muscle glycogen ~50% muscle triglycerides ~25% plasma free fatty acids ~25%

Question 27

what energy is used after one hour of exercise?

Answer 27

blood glucose and plasma free fatty acids provide more of the energy nutrients as muscle glycogen and triglycerides are being depleted

Question 28

what energy is used after two hours of exercise?

Answer 28

muscle glycogen and triglycerides are being depleted faster than they can be replaced blood glucose and plasma free fatty acids provide a greater and greater percentage

Question 29

what energy is used after three hours of exercise?

Answer 29

>70% of energy needs are being provided by blood glucose and plasma free fatty acids

Question 30

what energy is used after four hours of exercise?

Answer 30

>90% of energy fuel is provided by blood glucose and plasma free fatty acids muscle glycogen is fully depleted and muscle triglycerides provide >10% of energy needs

Question 31

at any given speed of movement, muscle groups with a high percentage of fast-twitch (FT) fibers exert more --- than those with muscle groups that contain primarily slow-twitch (ST) fibers

Answer 31

force

Question 32

muscle contractility can be measured and expressed as (2)

Answer 32

maximal titanic force | specific force generated

Question 33

specific force

Answer 33

the max force divided by muscle cross sectional area

Question 34

inhibitors of muscle differentiation (2)

Answer 34

myostatin | growth differentiation factor 8 (GDF8)

Question 35

what does loss of myostatin lead to?

Answer 35

increased muscle size

Question 36

what family is myostatin a member of?

Answer 36

TGF-beta

Question 37

myostatin actives

Answer 37

type 2 receptors

Question 38

in the case of the myostatin knockout muscle the max force is the same, but when corrected for the larger muscle size, the specific force is ---, meaning

Answer 38

lower | individual muscle fibers are weaker

Question 39

both endurance and resistance (weight) training result in a shift from

Answer 39

fast 2b myosin to 2a myosin

Question 40

training induced changes are small and do not result in

Answer 40

complete conversion

Question 41

aging is associated with a loss of muscle mass, known as

Answer 41

sarcopenia

Question 42

loss appears to follow which two phase?

Answer 42

10% is lost from age 25-50 | then a more rapid loss in muscle mass after age 50

Question 43

what can reduce or limit age related muscle loss?

Answer 43

regular exercise

Question 44

muscle loss also occurs with (2)

Answer 44

``` paralysis disuse atrophy (broken arm/leg) ```

Question 45

--- fibers have more ATP and cross bridges

Answer 45

fast

Question 46

sources of ATP required for muscle contraction (4)

Answer 46

glycolysis Krebs cycle glycogenolysis fatty acid oxidation

Question 47

glycogen is a

Answer 47

glycoprotein

Question 48

what does glycogen consist of?

Answer 48

a core protein glycoprotein

Question 49

branching of glycogen

Answer 49

highly branched structure made of glucose molecules connected through 1,6 and 1,4 glycosidic bonds

Question 50

during glycogen breakdown, the terminal residue is released as

Answer 50

glucose, subsequent ones as G1P

Question 51

glycogen phosphorylase

Answer 51

removes glucose

Question 52

glycogen deb ranching enzyme

Answer 52

breaks branches

Question 53

muscle glycogen content was measured directly for the first time using a --- --- method

Answer 53

needle biopsy

Question 54

using different diets, glycogen content of muscle could be changed dramatically from 0.6 g/100 g to 4.7 g/100 g for

Answer 54

protein and fat diet versus carbohydrate rich diet | diets were induced by first undergoing glycogen depletion

Question 55

individuals fed the carbohydrate Ruch diet displayed longer or extended muscle performance times when maintained at 75% of their max --- ---

Answer 55

oxygen consumption

Question 56

muscle glycogen content is a determinant of the capacity to do

Answer 56

long term heavy exercise

Question 57

muscle glycogen content can be manipulated depending upon diet following

Answer 57

glycogen depletion

Question 58

Type 0 | glycogen storage diseases

Answer 58

glycogen synthase deficiency (muscle) | symptoms: cardiomyopathy and exercise intolerance associated with complete absence of muscle glycogen

Question 59

``` type IXd (glycogen storage diseases) ```

Answer 59

muscle phosphorylase kinase deficiency symptoms: x-linked disease, relatively mild disorder characterized by variable exercise induced muscle weakness or stiffness

Question 60

why do we get cramps?

Answer 60

lactate builds up in the muscle

Question 61

triglycerides are highly concentrated stores of metabolic energy because they are

Answer 61

reduced and anhydrous

Question 62

the yield from oxidation of fatty acids is

Answer 62

9 kcal/g

Question 63

the yield from oxidation of carbohydrates and proteins are

Answer 63

4 kcal/g

Question 64

triglycerides are non polar and so are stored in nearly --- form

Answer 64

anhydrous

Question 65

more polar proteins and carbohydrates are more highly

Answer 65

hydrated

Question 66

what is the major reason triglycerides were selected in evolution as the major energy reservoir?

Answer 66

fat stores more than 6x as much energy as glycogen

Question 67

glycogen and glucose stores provide enough energy to sustain biological function for about ---, whereas triacylglycerol allows survival for

Answer 67

24 hours | several weeks

Question 68

metabolically, the enzymatic process of degradation of fatty acids to yield ATP energy requires

Answer 68

molecular oxygen

Question 69

muscles burning fatty acids must do so aerobically or anaerobically?

Answer 69

aerobically, which is slower than burning glucose anaerobically and utilizing the cori cycle

Question 70

4 steps of beta oxidation

Answer 70

oxidation hydration oxidation thiolysis

Question 71

weight is largely a function of how much

Answer 71

energy you consume versus how much you expend

Question 72

doping induces performance enhancing drugs by

Answer 72

steroids to boost muscle growth, narcotics to suppress pain, beta blockers to slow the heart rate (particularly helpful for fine motor control) and stimulants to add pep

Question 73

erythropoietin (EPO)

Answer 73

a naturally occurring hormone that is produced by the kidneys, which stimulates red blood cell production

Question 74

EPO stimulates

Answer 74

red blood cell production which can increase strain on the heart

Question 75

higher RBC counts should translate to a greater supply of

Answer 75

oxygen to tissues