Proteins

Question 1

Aliphatic

Answer 1

Side chains are non-polar and hydrophobic

Question 2

Aromatic

Answer 2

Planar unsaturated ring of atoms

Question 3

Sulphur containing

Answer 3

Disulphide bonds-Cysteine

Question 4

Basic

Answer 4

Side chain has neutral PH Lysine, Arginine, Histidine

Question 5

Acidic

Answer 5

Negatively charged side chain- Aspartate and Glutamate

Question 6

Uncharged Polar

Answer 6

Serine, Threonine, Asparagine and Glutamine

Question 7

Primary Structure

Answer 7

Polypeptide chain

Question 8

Secondary Structure

Answer 8

Alpha helix
Beta sheets
Local folded structures that form within a polypeptide due to interactions between atoms of the backbone

Question 9

Tertiary Structure

Answer 9

3-Dimensional structure of a polypeptide

Question 10

Forces within tertiary structure

Answer 10

Hydrogen bonds
Hydrophobic interactions
Disulphide bridge
Ionic interactions
Van der Waals

Question 11

Hydrogen bonds

Answer 11

1/20 of covalent bonds

similar to Van der Waals but stronger and more permanent

Question 12

Hydrophobic interactions

Answer 12

Interactions which exclude water- globular protein

Question 13

Disulphide

Answer 13

Interaction between two cysteine molecules

Question 14

Ionic

Answer 14

Occur between two oppositely charged R groups (side chains)

Question 15

Van der Waals

Answer 15

non-specific, weak attraction, stabilise structure in large number

Question 16

Quaternary Structure

Answer 16

Multiple polypeptide chains

Question 17

Haemoglobin

Answer 17

Quaternary
2 alpha
2 beta

Question 18

Protein denaturation

Answer 18

Disruption and possible destruction of both secondary and tertiary structures
Primary structure remains

Question 19

Causes of protein denaturation

Answer 19

Acids
Heat
Solvents (ethanol, methanol)
Cross linking reagents (formaldehyde)
Urea
Disulphide bond reducers

Question 20

Effects of Denaturation (4)

Answer 20

Decreased solubility
Altered water binding capacity
Loss of biological activity
Improved digestibility

Question 21

Peptidases

Answer 21

Cleavage of peptide bonds

Question 22

Endopeptidases

Answer 22

Cleavage on internal bonds

Question 23

Exopeptidases

Answer 23

Cleavage of amino acid one at a time

Question 24

Carboxypeptidases

Answer 24

Cleavage at -COOH terminal

Question 25

Aminopeptidases

Answer 25

Cleavage at NH2 terminal

Question 26

Glycoproteins

Answer 26

Sugar and protein

Question 27

Glycolated Hb

Answer 27

HbA1C

Question 28

Where does the glucose attach to on Hb

Answer 28

N terminal on Valine of the beta chain

Question 29

Type 2 diabetes can be diagnosed through

Answer 29

Hb1AC

Question 30

Lipoproteins

Answer 30

Protein and Lipids

Question 31

Function of lipoproteins

Answer 31

transport insoluble fats and cholesterol in blood (HDL, LDL)

Question 32

Apolipoproteins are____

Answer 32

Proteins that bind to lipids to fomr lipoproteins

Question 33

Metalloproteins

Answer 33

Protein that needs metal ion to be active

Haem molecule has 1 Fe molecule

Question 34

Collagen

Answer 34

Structural protein

Every 3rd amino acid is glycine

Question 35

Scurvy

Answer 35

Vitamin C is required to convert proline to hydroxyproline and lysine to hydrolysine which are essential for stabilising crosslinks between chains

Question 36

Osteogenesis Imperfecta

Answer 36

Glycine is substituted for larger amino acid
Protein is unable to form a tight coil
Loss of secondary and tertiary structure
Weakened and brittle collagen

Question 37

LDL receptor

Answer 37

Mosaic protein of 839 amino acids that mediate endocytosis of cholesterol rich LDL

Question 38

5 Classes that effect the receptors of LDL receptors

Answer 38

Class 1-5

Question 39

Class 1

Answer 39

no receptors produced

Question 40

Class 2

Answer 40

receptors never reach cell surface

Question 41

Class 3

Answer 41

Receptors can’t bind to LDL

Question 42

Class 4

Answer 42

Receptors don’t internalise

Question 43

Class 5

Answer 43

Receptors don’t release LDL