Proteins

Question 1

Structure of Amino acids

Answer 1

Amine group on the left, covalently bonded to a central C atom, which is also bonded to a R group above and a H atom below. To the right, the C is bonded to a carboxyl group

Question 2

What determines whether amino acids are polar or not?

Answer 2

If the R group has a -OH, -NH2 or -SH, it is polar.

Question 3

What is the primary structure of proteins?

Answer 3

Single polypeptide chain where different amino acids have been joined through condensation reactions

Question 4

What is the secondary structure of proteins?

Answer 4

Polypeptide chains fold due to hydrogen bonding between backbone of amino group and carboxyl group to make a beta pleated sheet or alpha helix structure

Question 5

What is the tertiary structure of proteins?

Answer 5

There is bonding between R groups to form a 3D structure

Question 6

What is the quaternary structure of proteins?

Answer 6

Not all proteins reach this step - when multipe proteins come together and form van der waal forces

Question 7

What types of bonding can occur between R groups in tertiary structure?

Answer 7

• Hydrogen bonds (between O and H)
• Disulphide bonds (Between 2 sulfurs)
• Ionic bonds (between r groups with opposite charges)

Question 8

What can split hydrogen bonds between R groups?

Answer 8

High temps and altered pHs

Question 9

What can split ionic bonds between R groups?

Answer 9

Altered pH

Question 10

What can split disulphide bonds between R groups?

Answer 10

Reducing agents

Question 11

What is formed when a polypeptide chain is formed?

Answer 11

Water from condensation reactions