1.9 Into to Proteins

Question 1

What are proteins made of?

Answer 1

Long chains of amino acids

Question 2

What is the structure of amino acids?

Answer 2

[from left to right]
NH2 attched to 2 C’s.
Middle C has an H at the top and an R group at the bottom.
C at the end is attached to a double bond O and an OH.

carboxyl, R-side chain, & an amino group

Question 3

What are peptide bonds? Polypeptide chains?

Answer 3

Amino acids connected together using amide bonds. A string of these amino acids are called poly peptide chains?

Question 4

What is the primary structure of a protein?

List points

Answer 4

• proteins organized in the precise sequence of amino acids that appear in the polypeptide chain
• starting point for determining the final structure of a protein
• small substitutions can greatly affect the protein by altering its ability to function and could affect protein folding

Question 5

Does the structure of a protein matter?

Answer 5

Yes
FUNCTION DETERMINES STRUCTURE
STRUCTURE DETERMINES FUNCTION

Question 6

What is the secondary structure of a protein?

List points

Answer 6

Different parts of the chain begin to fold on itself.
In this stage, the chain will fold in one of three ways:
1) alpha-helix (similar to DNA but single stranded)
2) beta-pleated sheet
3) random coil
It’s all held together by hydrogen bonds

Question 7

What is the tertiary structure of a protein?

List points

Answer 7

• When the secondary structure folds even more around itself
• many causes of this structure ex: H-bonding, hydrophilic/phobic interations, disulfide bridges (S-S), ionic boning, and proline kinks
• structures can either be globular (ex. hemoglobin) or fiberous (ex. hair)

Question 8

What is the quaternary structure of a protein?

Lists points

Answer 8

• proteins can be made of more than one polypeptide chain
• this is when the protein is folded around even more
• not all proteins have a quaternary structure
• interactions with other side chains here in this structure

Question 9

What are chaperone proteins?

Answer 9

Special proteins that help primary polypeptide chains fold and develop into tertiary structures.
“molecular supervisors”

Question 10

What is denaturation?

Protein denaturation

Answer 10

This occurs when proteins lose its shape, and therefore loses its function.
Sometimes this is temporary

Question 11

What can cause denaturation?

Protein denaturation

Answer 11

Causes include:
- temperature
- change in pH
- exposure to radiation
(Ex: cooking eggs)

Question 12

What are heat shock proteins (HSP)?
What do they do?

Answer 12

• a group of chaperone proteins is called HSP
• desgined to cling onto other proteins and prevent them from denaturation
• usually a low concentration of HSP until a stress is detected, in which they rapidly replicate and surround the cell to protect it