proteins

Question 1

name basic protein synthesis

Answer 1

DNA - transcription to RNA - translation to protein

Question 2

name some classes of amino acid

Answer 2

acidic, aromatic, aliphatic(hydrocarbon), basic(nitrogen group), sulphur-containing, uncharged polar

Question 3

what is a peptide bond

Answer 3

Formation of a covalent bond with the loss of 1 molecule of water

Question 4

what is the primary structure

Answer 4

The sequence of amino acids in a polypeptide chain

Question 5

what is the secondary structure

Answer 5

Is the spatial arrangement of amino acid residues that are near each other in the linear sequence
alpha helixes and beta sheets

Question 6

what is tertiary structure

Answer 6

The spatial arrangement of amino acid residues that are far apart in a linear sequence

Question 7

what is secondary structure held together by

Answer 7

h bonds

Question 8

what is tertiary structure held together by

Answer 8

van der Waals
Ionic interactions
Hydrogen bonds
Disulphide bridges
Hydrophobic interactions

Question 9

where and what are disulphide bonds

Answer 9

These are strong covalent bonds between two cysteine residues
They are common in extra-cellular proteins.

also bind the light and heavy chains in antibodies

Question 10

what is quaternary structure

Answer 10

Refers to the spatial arrangement of individual polypeptide chains in a multi- subunit protein

Question 11

what happens when a protein is denatured

Answer 11

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

Question 12

what are the 3 other types of proteins

Answer 12

Glycoproteins
Lipoproteins
Metalloproteins

Question 13

what are glycoproteins

examples?

Answer 13

Compound composed of protein and carbohydrate

Immunoglobulins

Question 14

what is glycosylation

Answer 14

post translation modification - where a sugar molecule binds to the protein

Question 15

what dose glycosylation do/ effect

Answer 15

Protein stabilisation 
Affect solubility
Protein Orientation 
Signalling
Cell recognition

Question 16

what are lipoproteins
what do they do
examples

Answer 16

Protein and lipids are either covalently or non-covalently bonded together

transport of water-insoluble fats and cholesterol in the blood

HDL, LDL

Question 17

what are metalloproteins

what are the functions

Answer 17

Protein molecule with a bound metal ion
help protein to be/do
Enzymes
		Storage
		Signalling
		Transport

Question 18

what are the 3 structures of proteins

Answer 18

globular , fiborius and membranpous

Question 19

what do globular proteins do

Answer 19

Enzymes
Messengers (hormones)
Transporters
Stock of amino acids
Structural function e.g. actin and tubulin

Question 20

what do fiborous proteins do

Answer 20

Bone matrices
Muscle fibre
Tendons
Connective tissue

Question 21

what do membranous do

Answer 21

Relay signals
Membrane transporters
Membrane enzymes
Cell adhesion molecule

Question 22

what is co-operative binding

Answer 22

the alteration of a proteins shape and assecsibility due to the binding of a molecule

Question 23

what is collagen

Answer 23

25 percent of proteins in humans (most in humans)

high tensile strength

Question 24

what type of proteins is a LDL receptor

where is it what dose it do

Answer 24

Glycoprotein
Present on the surface of all cells
Causing the internalisation of LDL - leading to the breakdown of LDL by lysosomes

Question 25

what is a lysosome

Answer 25

a vesicle containing degenerative enzymes