biological molecules

Question 1

describe covalent bonds

Answer 1

atoms share electrons

Question 2

what do carbs contain

Answer 2

carbon
hydrogen
oxygen

Question 3

name 3 monosaccharides

Answer 3

lactose
sucrose
glucose

Question 4

name 3 polysaccharides

Answer 4

cellulose
starch
glycogen

Question 5

glucose:
polar?
soluble?

Answer 5

polar+ soluble

Question 6

bonds in amylose

Answer 6

I-4
glycosidic
form long twisted chain

Question 7

bonds in amylopectin

Answer 7

1-4/1-6
glycosidic
form branched structure

Question 8

bonds in cellulose

Answer 8

hydrogen bonds

Question 9

what types of sugars are reducing sugars

Answer 9

all monosaccharides
some disaccharides
can donate electrons

Question 10

how to test for non-reducing sugars

Answer 10

Benedict’s test
boil with hydrochloric acid
sugars hydrolysed

Question 11

iodine test
what for?
how?

Answer 11

starch

few drops of iodine dissolved in potassium iodide solution

Question 12

lipids
polar?
soluble?

Answer 12

not polar/ soluble

Question 13

double chain is ……. fatty acids

Answer 13

unsaturated

liquids

Question 14

identification of lipids

Answer 14

emulsion test
sample mixed with ethanol
solutions mixed with water
white emulsions= lipids

Question 15

role of lipids

Answer 15

membrane formation
hormone production
electrical/ thermal insulation
buoyancy
protection of vital organs

Question 16

3 types of lipid

Answer 16

triglyceride

• 1 glycerol + 3 fatty acids
• ester bonds between mol.s

phospholipid

• modified triglycerides
• fatty acid chain replaced with a phosphate group

sterol
-4 carbon ring structure

Question 17

what enzyme catalyses the reaction of peptides =>amino acids

Answer 17

protease

Question 18

bonds in primary protein structure

Answer 18

peptide

Question 19

bonds in secondary protein structure

Answer 19

hydrogen bonds

Question 20

bonds in tertiary (and quaternary) protein structure

Answer 20

hydrophobic + hydrophilic interactions
disulphide bonds
ionic bonds
hydrogen bonds

Question 21

what bond is formed during condensation reaction

Answer 21

glycosidic

between carbons 1 and 4

Question 22

how are amino acids joined

Answer 22

hydroxyl in carboxyl group reacts with amine group of another
peptide bonds
condensation reaction
forms polypeptide

Question 23

name + describe types of proteins

Answer 23

globular

• water soluble
• proteins in tertiary structure
• regulate processes necessary for life
• e.g. insulin (hormone)

conjugated

• globular protein with non-protein prosthetic group
• lipids + carbs combine with proteins to form lipoproteins and glycoproteins
• e.g. catalase (enzyme)

fibrous

• many amino acids with hydrophobic r groups in primary structure
• make long strong mol.s NOT folded into complex 3D shapes
• e.g. keratin, elastin, collagen