chap 5 - proteins

Question 1

whos most at risk for too little protein in their diet?

Answer 1

old people who typically cant cook for themselves

Question 2

is it a waste to get protein enriched food?

Answer 2

yes

Question 3

how many A.A are there?

Answer 3

20

9 essential and 11 non-essentail

Question 4

how much Nitrogen in A.A?

Answer 4

average 16% of A.A by weight (amino group)

Question 5

Essentail A.A

Answer 5

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

HIS
ISO
LUE
LYS
MET
PHE
THR
TRY
VAL

Question 6

which A.A is an artifital sweetener?

Answer 6

phenyalanine

Question 7

What is PKU and why do we get tested for it?

Answer 7

is an inherited disease in which the body cannot metabolize a protein called phenylalanine.

leads to build up of Phenylketones which is toxic to the brain*

babies are tested for this*

Question 8

what determines a proteins final shape?

Answer 8

the amino acid sequece…

exmaple: insulin has disulfide bonds that make it curl

Question 9

How can you denature a protein?

Answer 9

acid or heat

Question 10

sickle cell anemia

Answer 10

reduced carrying capacity of oxygen in the blood

Amino acid change in H6

Question 11

what is the structure of a bloodcell?

Answer 11

bloodcell —> millions of Hemoglobin —> 4 myoglobin —> A.A and Fe2+ & heme group

Question 12

how many O2 can 1 hemoglobin carry?

Answer 12

4 because each hemoglobin is made of 4 myoglobin

Question 13

what foods provide most of our protein?

Answer 13

Meat, dairy, grain

each about 21% of our protein intake

although meat is the most packed with protein

Question 14

Reasons to need protein

Answer 14

1. Regulate body processes Ex.
   - hormones
   - insulin
   - enzymes
   - neurotransmitters
2. Tissue growth and repair
   - actin + myosin
   - collagen
3. Immune Defense
   - antibodies
4. Transport
   - hemoglobin
5. Energy (last resort)
   - 4kcal/g

Question 15

transamination

Answer 15

process of which non-essentail amino acids are made

Question 16

Protein digestion steps

Answer 16

1. mechanical breakdown in the mouth
2. digestion begins in the stomach HCL denatures proteins (pepsin is also activated which breaks proteins into polypeptides)
3. they are broken further down into di- tri- peptides and amino acids by enzymes from the pacreas (trypsin and chymotripsin). this all happens in the small intestine
4. they are then absorbved by the mucosal layer

Question 17

what happens after digestion and absorbtion of protein? where does the A.A go?

Answer 17

goes to the liver.
-this is where non-essential A.A are made
-can convert A.A to glucose (if needed)
-liver can use these A.A for energy
-con convert to fat (if needed)

after the liver… goes into bloodstream (2 Priorities)
1. makes proteins (enzymes, antibodies, NT)
2. broken down into free Amonia (Deamination) and sent back to the liver to be excreted as Urea

Question 18

what is endogenous protein? where does it come from?

Answer 18

within the body. the body takes A.A from the tissues

Question 19

what is exogenous protein? where does it come from?

Answer 19

A.A that comes from the diet

Question 20

Do we store excess A.A?

Answer 20

NO

Question 21

what determines the QUALITY of a protein?

Answer 21

• digestability of the protein
• Types of A.A used
• proportion of A.A in that protein

Question 22

what percentage of animal, plant, and Legume proteins are digested/absorbed?

Answer 22

animal: 90-99% digested

plant: 70-90% digested

Legumes: >90% digested and absorbed

Question 23

Legumes are high in everything except ___ and ____

Answer 23

Methionine and Cystine

comaired to eggs and breast milk which are high in everything “GOLDEN STANDARD”

Question 24

what are “complementary/supplementary proteins”?

Answer 24

combining two foods with limiting A.A

example:
Grains are high in Met+Cys but low in Lys
Legumes are high in Lys but low in Met+Cys

eat both, because they complement what eachother is missing (rice and beans)

Question 25

Protein quality: animal pro VS. plant pro.

Answer 25

Animal protein:
-good digestion and absorbtion
-has all A.A

Plant protein:
- incomplete protein (no plant has every A.A)
- missing at leat 1 A.A

Question 26

what is protein turnover?

Answer 26

protein is continously being broken down and synthesized

theres a rate at how often you body does this

Question 27

IAAO method

Answer 27

method is a noninvasive way to determine amino acid and protein requirements for people, animals, and children

can be used as an alterative to measuring Nitrogen Balaces

Question 28

DRI AMDR for protein

Answer 28

10-35% of calories from protein

Question 29

RDA value for protein (19+) and (6moths old)

Answer 29

0.8g/kg/day for 19+

1.52 g/kg/day for 6 months old

BUT WE GET 2x THIS CURRENTLY

Question 30

why can taking amino acid supplements be a concern?

Answer 30

BRAIN: A.A imbalance in the BBB beacuse trytophan is used to make NT

GI TRACT: gut can get overwhelmed and only take up one A.A instead of all of them