Proteins

Question 1

What atoms do all proteins contain

Answer 1

1. Carbon
2. Hydrogen
3. Oxygen
4. Nitrogen

Question 2

What atom do MOST proteins contain

Answer 2

Sulfur

Question 3

What atoms do SOME proteins contain

Answer 3

1. Zinc
2. Copper
3. Iron
4. Phosphorus

Question 4

How many calories per gram do proteins contain and what is the nitrogen content

Answer 4

4 calories per gram

16% nitrogen

Question 5

What are the four basic parts of amino acids

Answer 5

1. Side Chain (R group)
2. Amine group
3. Hydrogen atom
4. Carboxyl group

Question 6

how long can amino acids be stored in the body and how often do they need to be supplied

Answer 6

1. They are not stored in the body

2. Need to be supplied in the diet daily

Question 7

what bond joins amino acids

Answer 7

peptide bonds

Question 8

what is produced when two amino acids joined

Answer 8

dipeptide bonds and water

Question 9

Describe the primary structure of proteins

Answer 9

1. linear arrangement of amino acids

2. a sequence

Question 10

1. How many structures are in the secondary structure
2. What are these structures?
3. What dictates which is formed?

Answer 10

1. 3
2. Beta pleated sheets, alpha helix, random coil
3. the hydrogen bonds and pattern of backbone

Question 11

What are the 2 tertiary structures and their functions

Answer 11

1. Fibrous: structure, they are elongated molecules formed from repeating alpha helixes or beta pleated sheets and they are INSOLUBLE
2. Globular: transport, hydrophobic amino acids residues and hydrophilic residues, straight runs of secondary structure
   SOLUBLE

Question 12

What makes up the quaternary structure

Answer 12

more than 2 tertiary structures

Question 13

how does protein stability compare to carbs and lipids?

Answer 13

proteins change drastically when exposed to heat, air, osmotic pressure, or ph while carbs and lipids don’t change that much

Question 14

Define protein confirmation and denaturation

Answer 14

Denaturation: unfolding of protein molecule, changes shape without changing primary structure

Confirmation: normal structure and activity of protein

Question 15

2 physical denaturations of proteins and examples

Answer 15

1. heat: heating egg which then cannot go back to original form
2. air: when exposed to air proteins change and cannot return to original state

Question 16

2 ways proteins are chemically denatured

Answer 16

1. pH: pickle food

2. osmotic pressure: using salt to change structure of protein

Question 17

define reversible and irreversible protein denaturation

Answer 17

1. Reversible: protein can return to its original confirmation and biological activity
2. irreversible: protein cannot go back to original state or activity

Question 18

Define Complete and Incomplete protein quality and give sources of each

Answer 18

1. Complete: contains all essential amino acids in approximately the right proportions EX: meat and fish
2. Incomplete: lacks certain amino acids
   EX: nuts, seeds

Question 19

Define Protein complementation

Answer 19

completing the amino acid pattern by consuming complementing proteins, one contains what the other is lacking

BEANS AND RICE

Question 20

5 functions of protein in food

Answer 20

1. water binding
2. reduction
3. hydrolysis
4. texturize
5. emulsify

Question 21

what is protein hydrolysis and what is the necessary input

Answer 21

1. breaking down the peptide bond

2. water