topic 2.1.2: biological moleules

Question 1

describe the structure of ribose as an example of a pentose monosaccharide

Answer 1

5 C ring
OH group on 1,2 and 3
CH2OH on 5

Question 2

describe the structure of maltose

Answer 2

1-4 glycosidic bond between 2 alpha glucose

Question 3

describe the structure of sucrose

Answer 3

1-2 glycosidic bond between glucose and fructose

Question 4

describe the structure of lactose

Answer 4

1-4 glycosidic bond between glucose and galactose

Question 5

describe how a triglyceride is synthesised

Answer 5

OH from glycerol bonds with COOH from fatty acid to form an ester bond

Question 6

what are the 5 key cations?

Answer 6

Ca2+, Na+, K+, H+, NH4+

Question 7

what are the 4 key anions?

Answer 7

NO3-, HCO3-, CI-, PO43-

Question 8

describe the structure and function of starch

Answer 8

alpha glucose monomers, chains come in two forms:
amylose- long unbranched chain, 1-4 bonds make it coil
amylopectin- branched, 1-4 and 1-6
used by plants to store excess glucose

Question 9

describe the properties of starch

Answer 9

insoluble, large, branched, coiled, hydrolysis releases monomers

Question 10

describe the structure and function of glycogen

Answer 10

alpha glucose, 1-4 and 1-6 bonds
used by animals to store excess glucose

Question 11

describe the properties of glycogen

Answer 11

insoluble, compact, more branched than starch, large, releases monomers

Question 12

describe the structure and function of cellulose

Answer 12

polysaccharide of beta glucose, every other monomer flips
provides structural support for plant cells

Question 13

describe the structure of a triglyceride

Answer 13

glycerol backbone attached to 3 fatty acids with hydrocarbon chains varying in length

Question 14

describe the structure of a phospholipid

Answer 14

similar to triglyceride except one fatty acid is replaced by a phosphate group

Question 15

describe the properties of a triglyceride

Answer 15

long hydrocarbon tails (release energy), low mass to energy ratio (lots of energy in small vol) insoluble (don’t affect water potential), high ratio of H:O (release H2O when oxidised)

Question 16

describe the properties of a phospholipid

Answer 16

glycerol and phosphate are hydrophobic, tails are hydrophilic (allows bilayer to form)

Question 17

describe the properties and functions of cholesterol

Answer 17

polar molecule, binds to fatty acids to make bilayer more rigid

Question 18

describe the structure of an amino acid

Answer 18

central C atom, amino group, carboxyl group, H atom, and R group

Question 19

describe the condensation reaction that synthesises 2 amino acids

Answer 19

OH in carboxyl group + H in amino group, forms peptide bond

Question 20

describe the structure and properties of haemoglobin as a globular protein

Answer 20

two alpha and two beta chains (four O2 mols at a time), haem group, compact

Question 21

describe the structure and properties of insulin as a globular protein

Answer 21

two polypeptide chains held by disulfide bonds, soluble, specific shape

Question 22

describe the structure of amylase as a globular protein

Answer 22

single polypeptide chain, alpha helixes and beta pleated sheets

Question 23

describe the structure of a conjugated protein

Answer 23

globular protein with prosthetic group

Question 24

describe the properties of collagen as a fibrous protein

Answer 24

strong and flexible

Question 25

describe the properties of keratin as a fibrous protein

Answer 25

strong and insoluble, flexible or rigid depending on number of disulfide bonds