L2- Protein summary

Question 1

how many different levels of protien strucutre

Answer 1

4
primary
secondary
tertiary 
quarternary

Question 2

Primary

Answer 2

Structure and function

- peptide bonds

Question 3

Secondary

Answer 3

Localised folding

- hydrogen bonds

Question 4

Tertiary

Answer 4

ultimate folding of the protein

- disulphide, ionic, H bonds, Van Der Waals, hydrophobic

Question 5

quartenrayr

Answer 5

multiple subunit

-disulphide, ionic, H bonds, Van Der Waals, hydrophobic

Question 6

protein dentauration

Answer 6

losing confirmation of native state caused by breaking forces holding proteins together

Question 7

what can denature proteins

Answer 7

• heat (vibration)
• pH (alters ionisation state of amino acids)
• detergents/organic solvents (disrupts hydrophobic interaction

Question 8

example of protein misfolding which ca. cause disease

Answer 8

Transmissible spongiform encephalopathy e.g. BSE, Kuru, CJD

Question 9

protein folding is not

Answer 9

random- driven by the need to find the most stable conformation

Question 10

forces involved in maintaining proteins structure

Answer 10

• covalent
• electrostatic
• hydrogen
• hydrophobic
• van der waals

Question 11

covalent bond e.g. peptide bond

Answer 11

covalent bonds are strong

- broken by a reducing agent

Question 12

example of a covalent bond

Answer 12

disulphide bond between two cysteine

Question 13

most proteins with disulphide bonds re

Answer 13

secreted e.g. ribonuclease

Question 14

electrostatic interactsions

Answer 14

formed between electronegative atoms and a hydrogen bound to another electronegative atom

• salt bridges
• relatively strong

Question 15

hydrogen bonds

Answer 15

electrostatic interactions between water and nitrogen, oxygen or fluorine

Question 16

hydrophobic effect

Answer 16

interactions between hydrophobic side chains due to displaced water
- hydrophobic part will group together away from water

Question 17

van der waals

Answer 17

very weak

• due to dipole dipole interactions
• transient location of electrons at any given moment

intrinsic to any bond