Lesson 7.1 Proteins

Question 1

What are similarities and differences in amino acids?

Answer 1

All amino acids contain the alpha carbon, carboxyl group, and an amino group. They differ in the R-group / side chains.

Question 2

How can we identify whether side chains are nonpolar, polar, acidic, or basic?

Answer 2

Hydrophilic - Nonpolar side chains
Hydrophobic - Polar side chains
Acidic - side chain contains negative charge with a carboxyl group
Basic - side chain contains positive charge with an amino group

Question 3

What are the four levels of protein structure?

Answer 3

1. Primary - unique sequence of side chains
2. Secondary - coiled or pleated pattern caused by regular intervals of H bond
3. Tertiary - Final 3d shape of protein;determined by interactions between side chains
4. Quaternary - More than one polypeptide/protein bonded together

Question 4

What happens during denaturation?

Answer 4

When conditions like temperature, change in ph,and change in salinity disrupt the H and ionic bonds.

Question 5

Explain how tertiary structure is formed by interactions between side chains.

Answer 5

Hydrophobic interactions - clump together in middle to avoid contact
Hydrophilic interactions - form bonds with each other and others with a charge
Acidic and Basic side chains - attract to each other and form ionic bonds
Cysteine side chains - form bonds with each other

Question 6

Give examples of protein types and their functions.

Answer 6

Hormones - Carry molecular messages through blood
Enzymes - Cut and join molecules of life
Digestive Enzymes - Break food into small nutrient molecules
Infrastructure - support and move cells
Pumps,Channels,Receptors - get back and forth across membrane

Question 7

Why and how would the structure and function of a protein change if a hydrophobic amino acid was substituted for a hydrophilic one?

Answer 7

The structure and function would change as the new amino acid may not make the same interactions as the original which would lead to changes in the proteins shape.

Question 8

How are the effects and results of protein denaturation different from the effect and results of a mutation?

Answer 8

Denaturation changes the shape of a protein while mutation changes in the amino acid sequence. Denaturation doesn’t destroy the protein but it changes it’s functionally while mutations can destroy functions completely.