Protein and Amino acid

Question 1

protein accounts for how much of our total body mass?

Answer 1

15-16%

Question 2

structural proteins:

Answer 2

keratin in skin and hair

Question 3

protein enzymes:

Answer 3

glycolysis, citric acid cycle

Question 4

transport proteins:

Answer 4

glucose transporter, GLUT4, lipoprotein

Question 5

protective proteins:

Answer 5

antibodies

Question 6

Functional proteins:

Answer 6

actin and myosin in muscles

Question 7

signalling proteins:

Answer 7

hormones, insulin and glucagon

Question 8

what are all proteins composed of?

Answer 8

individual amino acids building blocks

Question 9

Amino acids are nitrogen containing compounds. T or F

Answer 9

T

Question 10

The 4th group is unique for each amino acid, why?

Answer 10

has implications for protein structure and function

Question 11

how many amino acids are commonly found in proteins?

Answer 11

20

Question 12

how are amino acids connected?

Answer 12

connected enzymatically through a peptide bond

Question 13

how are proteins created through DNA?

Answer 13

DNA is converted to RNA, read by a ribosome that connects amino acids together to form the protein

Question 14

what can happen to the protein if there is a change in the sequence of DNA?

Answer 14

dramatic changes on the proteins function

ex. altered polypeptide shape in red blood cells causes sicle cell disease

Question 15

what three ways are proteins broken down?

Answer 15

• Mechanical (chewing)
• Chemically (HCL in the stomach)
• Enzymatically (stomach and pancreatic enzymes)

Question 16

what are single amino acids and small peptides absorbed by?

Answer 16

mucosal cells of the small intestine

Question 17

once the amino acids and peptides are absorbed by the mucosal cells, what happens next?

Answer 17

peptides are broken down further and amino acids are transported to the liver

Question 18

how does the body recognize allergies?

Answer 18

Dietary proteins may be absorbed without being completely digested
The immune system may recognize these dietary proteins as a foreign antigen and mount an immune response

Question 19

what are the 3 steps in the body for an allergic reaction?

Answer 19

• First time, immune system is stimulated (sensitization)
• recognition as a foreign substance
• An immune response is mounted and an allergic reaction occurs

Question 20

what is the avg half life of a protein

Answer 20

~ 7 hours

Question 21

essential amino acids:

Answer 21

histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine

Question 22

non essential amino acids:

Answer 22

arginine, cysteine (cystine), glutamine, glycine, proline, tyrosine, alanine, asparagine, aspartic acid (aspartate), serine

Question 23

can proteins be broken down for energy?

Answer 23

yes

Question 24

can protein be stored for later?

Answer 24

yes

Question 25

what are the steps to storing protein?

Answer 25

- first step is removing the nitrogen group (deamination) - afterwards, the amino acid can enter the metabolic cycles to produce energy OR for storage as acetyl-CoA

Question 26

the liver processes amino acids, the nitrogen group is removed which creates what?

Answer 26

ammonia which is toxic

Question 27

what is ammonia combined with?

Answer 27

carbon dioxide

Question 28

what does carbon dioxide and ammonia generate?

Answer 28

urea

Question 29

how is urea excreted?

Answer 29

travels to the kidney and is excreted in the urine

Question 30

what is Phenylketonuria (PKU)?

Answer 30

Genetic disease where the gene for PAH is mutated and produces a non functional enzyme

Question 31

what is one of the common mutations for classic PKU?

Answer 31

a change from G to A at in the mRNA for the PAH gene

Question 32

what protein does Phenylketonuria (PKU) produce?

Answer 32

truncated protein which has lost of 99% of its activity

Question 33

how can PKU be managed?

Answer 33

limiting the dietary intake of phenylalanine

Question 34

how can brain damage be prevented with PKU?

Answer 34

must be detected early

Question 35

are infants screened for PKU?

Answer 35

yes, at birth

Question 36

why must aspartame be avoided for people with PKU?

Answer 36

artificial sweetener that is made from aspartate and phenylalanine

Question 37

what are the most common sources of animal proteins in Canada ?

Answer 37

Meat, fish, eggs and dairy products

Question 38

High intake of animal protein is associated with what?

Answer 38

high incidences of cardiovascular mortality

Question 39

what are plant sources of protein?

Answer 39

legumes, vegetables and grains - usually less expensive

Question 40

what food is a good source of both protein and fiber while containing less saturated fat?

Answer 40

beans

Question 41

High intake of plant protein is associated with?

Answer 41

decreased incidences of cardiovascular mortality

Question 42

what are complete protein sources?

Answer 42

Animal proteins, they contain all the amino acids

Question 43

what are incomplete protein sources? And why are they incomplete?

Answer 43

Plant proteins (apart from soy protein), still contain all the amino acids, but they may not be in the same proportions as human proteins

Question 44

what are complementing protein sources?

Answer 44

plants containing complementary amino acids to provide all essential amino acids

Question 45

how is protein quality assessed?

Answer 45

using a calculation called the DIAAS- Digestible Indispensable Amino Acid Score

Question 46

what does the DIAAS- Digestible Indispensable Amino Acid Score assess in protein?

Answer 46

accounts for the amino acids composition of a food but also the amount of amino acids that are absorbed

Question 47

what food group tends to have a higher score on the DIAAS?

Answer 47

meat

Question 48

the recommendation dietary allowance (RDA) for protein is based on what?

Answer 48

based on weight and growth needs

Question 49

when are protein and amino acid supplements worth it?

Answer 49

If dietary intake is deficient in protein

Question 50

when are protein and amino acid supplements not worth it?

Answer 50

If protein is being consumed in the diet

Question 51

Protein & Amino Acid Supplements will not help with immunity or muscle growth unless:

Answer 51

dietary intake was insufficient

Question 52

when are plant based milk a good alternative for adults?

Answer 52

those who may be lactose an tolerant

Question 53

should plant based milk be used as a replacement for human milk or infant formula?

Answer 53

NO

Question 54

what is Kwashiorkor

Answer 54

severe protein malnutrition and bilateral extremity swelling

Question 55

how does edema occur with Kwashiorkor?

Answer 55

without adequate protein, oncotic pull decreases and fluid remains in the tissues (edema)