1.9 Proteins

Question 1

List 5 functions of proteins

Answer 1

1. structural proteins
   2.Enzymes
   3.Pigaments
   4.Hormones
   5.Immunoglobins

Question 2

What is the function of structural protein

Answer 2

-Makeup body parts

Question 3

What is the function of enzymes

Answer 3

-biological catalysts

Question 4

What is the function of pigment

Answer 4

-colored protein
-(it is a part of structural protein)

Question 5

What is the function of Hormones

Answer 5

-regulatory proteins
-Control metabolic pathways

Question 6

Immunoglobulins

Answer 6

-Antibodies

Question 7

Are enzymes soluble or insoluble

Answer 7

soluble

Question 8

State a fact about solubility in all 5 functions of proteins

Answer 8

They are all soluble except for structural proteins

Question 9

Give examples of structural proteins

Answer 9

-Myosin= Makes up muscle fibers
-Keratin=Hair and fur
-Collagen= skin and joints
-Microtubules & filaments= help support cell
-Bones and teeth

Question 10

Give examples of enzymes

Answer 10

-Amylase= hydrolysis reaction of polysaccharides into monosaccharide

-Pepsin=Hydrololsis of protein into aminoacids

-Lipase= Hydrolosis of lipids into glycerol and fatty acids.

Question 11

Give examples of pigament

Answer 11

-melanin
-hemoglobin= red pigment in RBC
-chlorophyll
-Anthocyanin

Question 12

Give examples of hormones

Answer 12

-Adrenaline
-Thyroxine= regulates metabolism.

Question 13

What determines the sequence of amino acids in proteins

Answer 13

The DNA

Question 14

What determines the function of the protein?

Answer 14

The primary structure because it determines the secondary and tertiary structures.

Question 15

What is the secondary structure caused by

Answer 15

Cause by H-bonds between N-H(+) and C=O(-) of different amino acids.

Question 16

How are the folds of b-pleated sheet

Answer 16

-More than 1 chain can H bond resulting in larger molecules
-mostly structural protein.

Question 17

What is mostly a structural protein

Answer 17

Secondary structure- more specifically B-pleated sheet.

Question 18

Is secondary b-pleated sheet soluble or insoluble

Answer 18

Insoluble

Question 19

Is secondary helix soluble or insoluble

Answer 19

soluble protein

Question 20

Tertiary structures are either…

Answer 20

1- H bonds between polar groups
2- disulfide bridges between neighboring sulfhydryl groups
3- Hydrophobic interactions of non-polar groups.

Question 21

What are tertiary structures

Answer 21

Further foldings cause by interactions of R-side chains.

Question 22

What are quaternary structures

Answer 22

2 or more protein chains interact together
may contain prosthetic group

Question 23

Give 2 examples of Quaternary structures

Answer 23

1. Hemoglobin with Fe
2. 2 amino acid chains.

Question 24

What causes denaturation of a protein?

Answer 24

-High heat
-High or low pH
-Heavy metals
-Organic solvents (dissolve non-polar groups)
-Detergents

Question 25

What happens in stage 1 (B) in Denaturation

Answer 25

• The H-bonds break
  -May regain a 3-d Structure (renaturation)

Question 26

What happens in stage 2 (C)

Answer 26

• Disulfide linkages break resulting in coagulated proteins (insoluble)
  -Irriversible