chap 5 proteins

Question 1

what is the basis structural component of proteins and what does it contain

Answer 1

amino acid -> carbon, hydrogen, oxygen, nitrogen

Question 2

It is the _ that distinguishes
them from the composition of carbohydrates,
fats, and alcohol

Answer 2

nitrogen

Question 3

when does a amino acid is essential vs non essential and why is it important

Answer 3

• if nitrogen balance is negative = indispensable
• essential (indispensable) cannot be synthesized by the body and need to be ingested by food

lack of essential AA limits protein synthesis

Question 4

how many AA are essential vs non essential

Answer 4

9 non, 11 essential

Question 5

protein quality is determined based on

Answer 5

the amounts and
types of amino acids and the extent to which the amino acids are absorbed

Question 6

what is the international method for determining protein quality

Answer 6

protein digestibility corrected amino acid score (PDCAAS)

Question 7

animal protein are termed complete or incomplete protein and why

Answer 7

complete ­ proteins because they contain all the indispensable amino ­ acids in the proper amounts and proportions to each other to prevent amino acid deficiencies and to ­ support growth.

Question 8

plant protein are considered complete or incomplete protein and why

Answer 8

plant proteins may lack one or more of the
indispensable amino acids or the proper concentrations and are termed ­ incomplete proteins

Question 9

what is the concept of complementary proteins

Answer 9

pair different plant proteins with each other and bring the total concentration of all the indispensable amino acids to an adequate level.

Question 10

what determine how a protein functions

Answer 10

primary structure of the polypeptide

Question 11

what is the primary structure of a protein

Answer 11

sequence of AA forming one or more polypeptide chain

Question 12

what is the secondary structure of a protein

Answer 12

coiling or folding of its polypeptide chain due to hydrogen bonding within or between AA chain -> give the shape of the protein

Question 13

what is the tertiary structure of protein

Answer 13

3-D shape of polypeptide caused by weak interaction among side groups and between side group and the fluid environment

Question 14

what is the quaternary level structure of protein

Answer 14

final 3D structure formed by all polypeptide, composed of 4 polypeptide chain,

Question 15

what is a conditionally indispensable AA

Answer 15

Under normal conditions, an amino acid that can be manufactured by the body in sufficient amounts, but under physiologically stressful conditions,
an insufficient amount may be produced.

Question 16

which AA are often limiting

Answer 16

lysine, threonine, cysteine, methionine

Question 17

what is a complementary protein

Answer 17

incomplete proteins that
when eaten together provide a full complement of all essential amino acids.

Question 18

what are the protein function in the body

Answer 18

• Enzymes
• Hormones & Cytokines
• Structural proteins
• Transport proteins
• Immune system proteins
• Acid-base regulator
• Fluid regulator
• Energy

Question 19

where does protein digestion begins

Answer 19

in the stomach when protein is in contact with gastric juice -> denature begin

Question 20

what is the role of HCI in the gastric juice of stomach

Answer 20

denature protein (change structure) and activate pepsin, enzyme that break polypeptide into smaller unit (10-20% digestion)

Question 21

where is the majority of digestion of protein occurs

Answer 21

small intestine

Question 22

where come the digestive enzyme that are activate in small intestine for protein digestion

Answer 22

pancratic juice and cell of the brush border

Question 23

large polypeptide that entered from the stomach are broken down in what

Answer 23

tripeptide, dipleptide and AA

Question 24

where protein absorption occurs and which one btw essential or non essential AA are absorbed more rapidly

Answer 24

entire small intestine, non-essential

Question 25

% of peptides and free AA aborsbed

Answer 25

67% as peptides 33% as free AA

Question 26

what does exogenous means

Answer 26

originate from outside of the body

Question 27

what does endogenous mean

Answer 27

originate from inside the body

Question 28

The amino acid pool contains amino acids recently absorbed from

Answer 28

food and from the breakdown of skeletal muscle tissue

Question 29

what is the amino acid pool

Answer 29

free amino acids that are circulating in the blood or in the fluid found within or between cells.

Question 30

The constant change in the body proteins as a result of protein synthesis and breakdown is referred to as

Answer 30

protein turn over

Question 31

what is a major site for amino acid metabolism

Answer 31

the liver

Question 32

the uses of protein for energy is a catabolic or anabolic process

Answer 32

cata

Question 33

What is the fate of the amino acids absorbed from the gastrointestinal tract and transported to the liver?

Answer 33

20% is used by liver and 50-65% are absorbed by liver

Question 34

purpose of catabolism

Answer 34

1. Degrades damaged proteins 2. Provides energy 3. Synthesis of other compounds

Question 35

what is transmination

Answer 35

involves the transfer of an amino group to another carbon skeleton,

Question 36

what is deamination

Answer 36

refers to the removal of the amino group from the amino acid. When the amino group is removed, the remaining compound is an ­ alpha-keto acid (a-keto acid), frequently referred to as the ­ carbon skeleton.

Question 37

transamination in the liver allows what

Answer 37

liver to manufacture dispensable AA from indispensable AA

Question 38

creatine synthesis begin where and end where

Answer 38

begin in kidney and completed in liver

Question 39

what happen with ammonia

Answer 39

- in muscle: form glutamine from glutamate - in liver: converted to urea - can also be excreted in sweat

Question 40

AA that undergo significant oxidation in muscle

Answer 40

Asparagine ¡ Aspartate ¡ Glutamate ¡ Isoleucine ¡ Leucine ¡ Valine

Question 41

the source of approximately half of the ATP used by the liver comes from

Answer 41

aa

Question 42

% of the total energy that come from AA is

Answer 42

3 to 5% but during higher prolonged intense exercise AA is an important source of energy

Question 43

why AA can be a major source of energy during endurance exercise

Answer 43

due to depletion of glycogen -> result in increased oxydation of leucine

Question 44

which AA are the only one that cannot make glucose

Answer 44

leucine and lysine

Question 45

AA will be converted in what to produce glucose

Answer 45

pyruvate

Question 46

what is nitrogen balance

Answer 46

the difference between total nitrogen (protein) intake and total nitrogen loss (via the urine and feces), usually determined over several weeks.

Question 47

net protein balance involve what

Answer 47

muscle protein synthesis (MPS) = muscle protein breakdown (MPB)

Question 48

. ­ Positive net protein balance occurs when

Answer 48

MPS > MPB

Question 49

Adults who want to be in a muscle growth state must achieve

Answer 49

positive nitrogen balance and positive net protein balance.

Question 50

when does a person is in a positive nitrogen balance

Answer 50

When intake is greater than loss

Question 51

protein intake > _ is not recommended

Answer 51

2.5

Question 52

high quality protein allow what

Answer 52

++ protein synthesis

Question 53

does protein intake before exercise has an effet

Answer 53

no

Question 54

does protein intake during exercise has an effet

Answer 54

unclear but may maximize anabolic responses

Question 55

how munch protein intake is recommended throughout the day

Answer 55

25-35g

Question 56

what is the anabolic window

Answer 56

first hour or two after exercise -> intake of protein after exercise = increase AA in blood = increase MPS

Question 57

whey protein is high in which AA

Answer 57

leucine

Question 58

effect of protein intake after exercise

Answer 58

support muscle growth, increase strength and power and body composition

Question 59

strategies to maximise protein intake after resistance exercise

Answer 59

- Immediately after exercise, when possible, but no later than 2 hours after exercise - High-quality protein containing a large amount of indispensable amino acids (such as egg white, whey, casein, and soy) - ~15 to 25 g of protein (0.25 to 0.3 g/kg) as a food, beverage, or protein supplement - For maximum protein synthesis, high quality protein source containing ~1.7 to 2.4 g of leucine

Question 60

which protein is considered high quality

Answer 60

milk, dairy, egg, whey protein isolate

Question 61

for athlete that don't consume animal product which source of protein is important

Answer 61

soy

Question 62

how munch protein intake prior to sleep

Answer 62

>40g

Question 63

The amount of protein associated with maximum protein synthesis after resistance exercise is

Answer 63

25g or > 2g/kg/d

Question 64

Protein intake in athletes with disordered eating or eating disorders

Answer 64

0,7-1.2 g/kg

Question 65

what happen under starvation (protein)

Answer 65

hormonal balance change -> decrease insulin production, muscle and fat cell become resistant to insulin -> decrease MPS because insulin promote uptake of AA by muscle celll -> increase MPB

Question 66

daily energy deficit should an athlete dieting have + daily protein intake

Answer 66

500 kcal, 1.8 g/kg and as high as 2.7

Question 67

is protein supplement better than food source

Answer 67

no better or worse

Question 68

protein supplement usually contain what

Answer 68

whey, casein, egg, soy proteins

Question 69

carnosine is in greater concentration in type 1 or 2 fiber

Answer 69

type 2

Question 70

which AA is the rate limiting factor of carnosine manufacture

Answer 70

beta-alanine

Question 71

role of carnosine in the muscle

Answer 71

buffer acid and maintain muscle pH within normal range -> important to enhance buffering during high-intensity

Question 72

Glutamine supplementation does/does not appear to be effective as a way to enhance the functioning of the immune system

Answer 72

does not

Question 73

Glucosamine/chondroitin sulfate is generally effective/ not effective for reducing joint pain

Answer 73

not effective

Question 74

The chemical composition of proteins differs from carbohydrate or fat because of the presence of

Answer 74

nitrogen

Question 75

the primary structure of the protein determines its

Answer 75

function

Question 76

The amino acids that are most rapidly absorbed from the intestine are:

Answer 76

indispensable

Question 77

which athlete would use protein as an energy source to the greatest extent

Answer 77

ultra endurance athletes

Question 78

amount of protein recommended daily for athletes in training on a kg of body weight basis is:

Answer 78

1.0 to 1.8g

Question 79

Which of the following is (are) recommended for post exercise intake: a. low-fat chocolate milk b. fruit-in-the-bottom yogurt c. turkey sandwich d. all of the above

Answer 79

d

Question 80

why do athlete who restrict their energy intake need more protein

Answer 80

more protein will be burned for energy

Question 81

which of the following systems is highly dependent on protein because of rapid cell turnover: a. renal c. neurologic b. immune d. cardiovascular ­

Answer 81

b

Question 82

how do whey and Casein differ

Answer 82

each is compromised of different amino acids

Question 83

which of the following is not an example of complementary protein or mutual supplementation: a. red beans and rice b. pinto beans and corn tortillas c. tofu and rice d. scrambled eggs with nonfat milk

Answer 83

d. scrambled eggs with nonfat milk

Question 84

what is the AA considered conditionally indispensable in long distance runner

Answer 84

glutamine

Question 85

what is the mechanism for beta-alanine supplementation

Answer 85

prevention of the breakdown of cartilage