Chapter 4 Proteins

Question 1

What are the building blocks that make up our proteins?

Answer 1

amino acids

Question 2

Does each protein have the same sequence of amino acid chains?

Answer 2

no

Question 3

How is the amino acid pool created?

Answer 3

when protein foods are eaten and broken down

Question 4

What can we use amino acids for?

Answer 4

building new protein

Question 5

what is in the amino group in an amino acid?

Answer 5

NH2

Question 6

how many amino acids do we need to make every protein in our body?

Answer 6

20

Question 7

what makes each amino acid different?

Answer 7

the unique side off the central C changes. the top part stays the same

Question 8

How is a protein made?

Answer 8

Take two amino acids, dehydrate them. Extract OH from one and H from another, which causes a bond between the C and N.

Question 9

What is the bond between C and N called when joining two amino acids?

Answer 9

peptide bond.

Question 10

What are amino acids that cannot be manufactured in our body and must be consumed in food called?

Answer 10

indispensable (essential)

Question 11

what are amino acids called that we have the ability to produce (synthesize)?

Answer 11

dispensable (non essential)

Question 12

what amino acids can normally be made in the body but in certain conditions, we may require temporary dietary intake it in the diet?

Answer 12

conditionally indispensable amino acids

Question 13

Normally, is intake and output of protein equal (in equilibrium)?

Answer 13

yes

Question 14

What is it called when we take proteins in and break them down or break them down from tissues in the body?

Answer 14

catabolism

Question 15

What is it called when we take amino acids and use them to build new proteins?

Answer 15

anabolism

Question 16

Explain deamination

Answer 16

amino acids break down and remove the Nitrogen group. The N makes urea and then is excreted through the urine.

The remaining O and H are called residue and they can convert to carbohydrates and fats

Question 17

What are the three contributors to the amino acid pool?

Answer 17

dietary protein
protein from breaking down tissue (catabalism)
plasma proteins

Question 18

What four things can the amino acid pool create?

Answer 18

Nitrogen via deanimation
Fats/Carbs via deanimation
Creating tissue
plasma proteins

Question 19

What can we look at to determine our protein balance?

Answer 19

nitrogen balance

Question 20

What does looking at our nitrogen balance indicate?

Answer 20

how well our tissues are maintained

Question 21

What measure determines nitrogen balance? How much nitrogen excreted per level of intake.

Answer 21

1 g of nitrogen is excreted for every 6.25g of nitrogen from the diet and metabolism

Question 22

What is positive nitrogen balance?
When in life does it normally occur?

Answer 22

stores more nitrogen than it excretes
rapid growth, pregnancy, lactation, following illness

Question 23

What is negative nitrogen balance?
Why does it happen and what does our body do in response?

Answer 23

body takes in less nitrogen than it excretes
results from inadequate protein intake
body will break down tissue to supply amino acids

Question 24

What are the 6 functions of protein?

Answer 24

build tissue
water balance
pH balance
metabolism
body defense system
energy (4 kcal/g)

Question 25

How does the amino acid act as a buffering agent to regulate pH?

Answer 25

The amino acid can let go of the H in the carboxyl group when we are too alkaline. H ions make us acidic, which would help balance the pH If we are too acidic, the NH2 group can act as a base and accept extra H from the blood, raising the pH to become more alkaline

Question 26

What is the term for when the amino acid has the ability to act as an acid and a base?

Answer 26

amphoteric

Question 27

What are most enzymes in our body made of?

Answer 27

proteins

Question 28

How many indispensable (essential) amino acids are there?

Answer 28

9

Question 29

What complete protein sources supply the 9 indispensable (essential) amino acids?

Answer 29

eggs, milk, cheese, meat, fish, poultry, soy

Question 30

What are sources of incomplete indispensable (non essential) amino acids?

Answer 30

grains, legumes, nuts, seeds, fruits, vegetables

Question 31

How do vegetarian diets consume all amino acids if the 9 complete essential amino acids come from animals?

Answer 31

they have to heat the right variety of plant based foods to get all the amino acids

Question 32

List the types of vegetarian diets

Answer 32

lacto-vegetarian (dairy) ovo-vegetarian (eggs) lacto-ovo vegetarian (dairy and eggs) vegan (no animal foods)

Question 33

Benefits of vegetarian diets

Answer 33

decreased fat and cholesterol, obesity, CVD, diabetes, cancer risk improved lipid panels

Question 34

Explain digestive process of proteins

Answer 34

Mouth - mechanical digestion Stomach - stomach secretes pepsinogen (inactive form of protein enzyme) which is activated by hydrocholoric acid from the stomach, and creates pepsin. Pepsin breaks proteins into smaller proteins. Makes chyme and polypeptides. Small intestine - polypeptides come in contact with pancreatic and intestinal proteases, which breaks down proteins into dipeptides and amino acids. Pancreatic enzymes trypsin, chymotrypsin, and carboxyypeptidase assist with hydrolysis. Peptides aminopeptidase and dipeptidase break it all down into amino acids.

Question 35

What are the three pancreatic enzymes used in protein digestion?

Answer 35

trypsin chymotrypsin carboxypeptidase

Question 36

What activates trypsinogen to turn into trypsin?

Answer 36

enterokinase

Question 37

What does the pancreatic enzyme trypsin do?

Answer 37

digests large polypeptides into small dipeptides

Question 38

what does trypsin activate that gets converted to chymotrypsin?

Answer 38

chymotrypsinogen

Question 39

what activates the pancreatic enzyem carboxypeptidase to be released and break down proteins into small peptides and amino acids?

Answer 39

trypsin

Question 40

What does aminopeptidase that is secreted from the small intesting in protein digestion do?

Answer 40

produce small peptides and amino acids

Question 41

what does dipeptidase that is secreted from the small intestine in protein digestion do?

Answer 41

splits dipeptides into amino acids