Protein structure

Question 1

What type of polymers are polypeptides and proteins

Question 2

How is the shape of the protein held together?

Answer 2

• complex shapes
• hydorgen bonds
• as well as other intermolecular force
• as well as disulfide bridges

Question 3

Why is the shape of proteins important?

Answer 3

• vital to their functions
• enzymes and structural materials in living thing

Question 4

What does helical mean? WHy does a protein have this shape?

Answer 4

spiral

due to hydrogen bonds between molecules

Question 5

What is pleating?

Answer 5

another arrangement of a protein

protein ends up in a pleated sheet

parallel chains held together by hydrogen bonds

Question 6

What is wool?

Answer 6

• protein fibre
• with a helix
  *

Question 7

Why is wool stretchy?

Answer 7

• held together by H-bonds which stretch and the fibre extends
• releasing the tension allows the hydorgen bonds to returns to their normal length and the fibre returns to its original shape
• however, washing at high temperatures can permanently break the H-bonds and a garment may permanently loose its shape

Question 8

Where does hydrogen bonding occur between amino acids?

Answer 8

C=O groups and -N-H groups

shown as C=O···H-N

Question 9

What other bonding is present between amino acids?

Answer 9

• ionic attracts
  
  • between groups on the side chain of amino acids that contain ions
• sulfur-sulur bonds
  
  • amino acid cysteine has a side chain with an -CH₂SH
  • under suitable oxidising conditions, two cysteine molecules may react to form a sulfur-sulfur bond that forms a bridge between the two molecules
  • creates a double amino acid called cysteins
  • aka disulfide bridge