Biomolecules

Question 1

General formula of carbohydrates

Answer 1

CH2O

Question 2

Monosaccharide characteristics

Answer 2

• soluble
• hexose/pentose
• struc isomers

Question 3

Pentose monosaccharides

Answer 3

• ribose
• doexyribose

Question 4

Hexose monosaccharids

Answer 4

• glucose
• fructose
• galactose

Question 5

Carb uses generally

Answer 5

• energy source
• structure of cells

Question 6

Carb uses forensically

Answer 6

• distinguish between plant/animal
• PMI using carb decomposition biomarkers
• used in drug bulking, can be used to ID certain ‘brands’

Question 7

Disaccharide

Answer 7

Glycosidic linkage of 2 monosaccharides

Question 8

Disaccharides and their monomers

Answer 8

• glucose + glucose = maltose
• glucose + galactose = lactose
• glucose + fructose = sucrose

Question 9

Polysaccharide

Answer 9

complex molecules that are INSOLUBLE in water

Question 10

What monomer makes up starch

Answer 10

glucose

Question 11

Lipid uses generally

Answer 11

• makes up bilayers/membranes
• energy storage
• cell signalling

Question 12

Lipid uses forensically

Answer 12

• ID of bacteria
• detection of water contamination
• PMI estimation and clandestine grave ID

Question 13

Glycolipid

Answer 13

• present in membranes
• heads contain oligosaccharide

Question 14

Sterols

Answer 14

• present in membranes
• heads contain steroid ring i.e. cholesterol

Question 15

Phospholipid

Answer 15

• present in membranes
• +ve head, -ve phosphate tail

Question 16

Protein uses generally

Answer 16

• structure
• catalyst / regulation i.e. enzyme, hormone

Question 17

Primary protein structure

Answer 17

sequence of amino acids in chain

Question 18

Secondary protein structure

Answer 18

Folding of polypeptide due to hydrogen bonding
- a-helix; H bonds every 4th peptide
- b-pleated sheet; can be parallel or anti-parallel

Question 19

Hair / a-keratin

Answer 19

• 2 or more a-helices; stretch and untwist to give hair springiness
• structure determined by sulphide bridges
• can trap drugs

Question 20

Tertiary protein structure

Answer 20

More folding due to R group interactions i.e. H bonds, ionic bonds, disulphide bridges

Question 21

Quaternary protein structure

Answer 21

• multiple polypeptide chains join together via H, ionic, disulphide bridges

Question 22

Enzyme

Answer 22

• biological catalyst
• catalysis occurs at active site
• active site is 3D cleft formed (3/4 protein)
• requires co-factors

Question 23

Lock and key theory VS induced fit theory

Answer 23

• LaKT: enzyme and substrate are perfect match
• IFT: enzyme folds around substrate

Question 24

factors affecting protein folding

Answer 24

• sequence of amino acids in primary structure
• environment i.e. denaturation

Question 25

Enzyme Co-factors

Answer 25

- required by some for activity - small organic molecule or metal

Question 26

Enzyme competitive inhibitors

Answer 26

- compete for active site - can be overcome with addition of more substrate

Question 27

Enzyme non-competitive inhibitors

Answer 27

- bind to enzyme at a location other than the active site - causes polypeptide chain to change shape and become non-specific - cannot be overcome with addition of more substrate

Question 28

Protein extraction

Answer 28

- tissue homogenised - solvents used to dissolve protein fraction - protein purified

Question 29

Factors affecting method of protein purification

Answer 29

- ionic charge - size - binding affinities

Question 30

Ion exchange chromatography

Answer 30

- protein purification - charged resins bind to charged proteins - retention depends on strength of charge (weak = released first)

Question 31

Affinity chromatography

Answer 31

- protein purification - resins with attached ligands bind to specific protein via lock and key

Question 32

How are purified proteins analysed?

Answer 32

SDS-PAGE

Question 33

What does SDS-PAGE stand for

Answer 33

Sodium Dodecyl Sulphate Poly-Acrylamide Gel Electrophoresis

Question 34

Haemoglobin structure

Answer 34

2 alpha polypeptide units 2 beta polypeptide units