Week 4 - Protein

Question 1

What are essential amino acids?

Answer 1

amino acids that cannot be synthesized and must be consumed in the diet

Question 2

What are nonessential amino acids?

Answer 2

amino acids that can be made from others in the body

Question 3

How many essential amino acids are there?

Answer 3

9

Question 5

What are BCAAs?

Answer 5

branch-chain amino acids - leucine, isoleucine, and vailne

Question 6

what is the primary protein structure?

Answer 6

a sequence of amino acids that forms one or more polypeptide chains

Question 7

what is the secondary protein structure?

Answer 7

the coiling or folding of its polypeptide chains as a result of hydrogen bonding between amino acid chains

Question 8

What is tertiary protein structure?

Answer 8

a folded three-dimensional shape caused by weak interactions between side groups

Question 9

What is the quaternary protein structure?

Answer 9

the final 3d structure formed by all the polypeptide chains making up the protein

Question 10

how is protein broken down in the mouth?

Answer 10

by mechanical digestion (chewing), no enzymes

Question 11

How is protein digested in the stomach?

Answer 11

hydrochloric acid unfolds protein into long polypeptide chains

Question 12

How do the pancreas and small intestine contribute to protein digestion?

Answer 12

they contribute enzymes that break polypeptide chains into free amino acids and smaller chains

Question 13

How and where are amino acids absorbed?

Answer 13

they are absorbed by enterocytes that line the small intestine, then sent to the liver and released into circulation

Question 14

What are the three fates for absorbed amino acids?

Answer 14

1. incorporated into body protein or used to make other nitrogen compounds
2. be oxidized for energy (deamination)
3. contribute to the body’s glucose, ketone, and lipid pool

Question 15

how is protein synthesized?

Answer 15

1. transcription - DNA is split and copied to mRNA which is a recipe for protein
2. translation - mRNA recipe is read to make a polypeptide chain or peptide

Question 16

What happens if the body is missing a non-essential amino acid during synthesis?

Answer 16

the body will make it or obtain from the pool of amino acids in the liver via bloodstream

Question 17

What happens if the body is missing an essential amino acid during synthesis?

Answer 17

synthesis will stop and the incomplete protein will be tagged for break down - amino acids will be recycled to the liver pool

Question 18

What is kwashiorkor caused by

Answer 18

a lack of protein in the diet

Question 19

what are the effects of kwashiorkor?

Answer 19

change in skin hair color texture, fatigue, diarrhea, loss of muscle, failure to grow,
edema (swelling) of the ankles, feet, and belly
damaged immune system, etc

Question 20

what is phenylketonuria?

Answer 20

a rare inherited disorder that causes the amino acid phenylalanine to build up in the body

Question 21

how can phenylketonuria be treated?

Answer 21

a carefully monitored low protein diet, or dietary supplements without phenylalanine

Question 22

what are the effects of phenylketonuria?

Answer 22

cognitive damage and intellectual disabilities

Question 23

What is the protein RDA for adults?

Answer 23

0.8g/kg

Question 24

What percent of daily energy intake should be made up of protein?

Answer 24

10-35%

Question 25

What is an RDA?

Answer 25

amount of a nutrient that is thought to meet the needs of ~98% of the population

Question 26

How much protein should athletes take in per day?

Answer 26

~1.6g/kg body mass

Question 27

How much protein should elderly people have per day?

Answer 27

1-1.2g/kg

Question 28

What is the energy density of protein?

Answer 28

4kcal/g

Question 29

What are three roles protein has in physical activity?

Answer 29

1. maximizing gains in muscle mass and strength
2. preserving lean mass during calorie deficit weight loss
3. structural benefits to tendon and bone

Question 30

What do BCAAs do in the body?

Answer 30

can be directly oxidized by muscle, and appear to play an important role in triggering MPS

Question 31

What population would benefit from BCAA supplementation?

Answer 31

vegans and vegetarians

Question 33

Why is it important for vegetarians/vegans to combine a variety protein sources?

Answer 33

anima proteins contain high amounts of all amino acids, but some plant based sources have higher amounts of specific amino acids compared to others - so in order to get all amino acids, multiple sources must be used