11 protein classification

Question 1

proteins comprised of only 1 type of amino acid is called a:

Answer 1

simple protein

Question 2

a protein soluble in neutral, DISTILLED WATER

Answer 2

albumin

Question 3

a protein soluble in neutral dilute SALT

Answer 3

globulin

Question 4

a protein soluble in dilute acid or base

Answer 4

glutelin

Question 5

soluble in alcohol (ethanol)

Answer 5

prolamines

Question 6

insoluble in water and neutral salts

Answer 6

scleroproteins

Question 7

basic proteins (contain a lot of lysine and arginine)

Answer 7

histones

Question 8

food science is most interested in what classes of proteins?

Answer 8

albumins and globulins

Question 9

conjugated proteins

Answer 9

contain chemical moieties other than amino acids

Question 10

a non-amino acid component of a protein is called a:

Answer 10

prosthetic group

Question 11

prosthetic groups include:

Answer 11

• lipoproteins
• glycoproteins
• metaloproteins
• phosphoproteins

Question 12

carbohydrate usually attaches to OH group of what amino acids by O-glycosidic linkage?

Answer 12

threonine, serine

Question 13

carbohydrate usually attaches to amide group of what amino acid by N-glycosidic linkage?

Answer 13

asparagine

Question 14

what’s a metaloprotein?

Answer 14

protein mixed with metal ion that’s loosely chelated

Question 15

give 2 examples of metaloproteins

Answer 15

hemoglobin and myoglobin - they chelate Fe2+ in porphoryn rings

Question 16

numerous ______ have metal ions as their prosthetic group

Answer 16

enzymes

Question 17

what’s a phosphoprotein?

Answer 17

proteins conjugated to inorganic phosphates

Question 18

give examples of phosphoproteins

Answer 18

casein, rennin

P is linked to OH groups of ser and thr

Question 19

denaturation disrupts what structures of a protein?

Answer 19

secondary and tertiary

Question 20

denaturation:

Answer 20

change in structure or conformation that doesn’t involve breaking of peptide bonds

Question 21

what are the interactions disrupted in denaturation?

Answer 21

• H bonds
• electrostatic bonds
• hydrophobic interactions
• van der waal’s forces

Question 22

denaturation causes a lot of _______ properties to change

Answer 22

physical

Question 23

denaturation generally (increases/decreases) water solubility?

Answer 23

decreases

Question 24

denaturation can cause an (increase/decrease) in viscosity?

Answer 24

increase

Question 25

denaturation (promotes/inhibits) crystallization

Answer 25

inhibits

Question 26

what can occur if proteins are denatured to the point where their secondary structures are completely disrupted?

Answer 26

• polymerization or aggregation

leading to gel formation or precipitation

Question 27

what factors influence denaturation?

Answer 27

• temp
• pH
• changes in ionic strength
• chemical agents
• surface forces

Question 28

shift in pH effects which protein structure?

Answer 28

tertiary (electrostatic)

Question 29

what is one substance used to compete with peptide linkage for H bonds? disrupts both tertiary and secondary structures

Answer 29

urea