biological molecules, dna and enzymes

Question 1

thymine and cytosine

Answer 1

pyrimidine bases

Question 2

magnesium ions

Answer 2

produce chlorophyll

Question 3

sucrose

Answer 3

made of alpha glucose and fructose

Question 4

polysaccharides good for storage

Answer 4

insoluble so doesn’t affect water potential, compact

Question 5

starch

Answer 5

made of amylose and amylopectin

Question 6

glycogen

Answer 6

energy store for animals and fungi

Question 7

amylopectin

Answer 7

alpha glucose, 1-4 and 1-6 glycosidic bonds

Question 8

test for non reducing sugars

Answer 8

after benedict’s test heat with acid then repeat test - acid hydrolyses disaccharide

Question 9

roles of lipids

Answer 9

energy, waterproofing, insulation, protection

Question 10

tertiary structure

Answer 10

secondary structure twisted further into 3D shape

Question 11

globular protein

Answer 11

haemoglobin

Question 12

structure of haemoglobin

Answer 12

four polypeptide chains held by disulfide bonds, haem group with iron molecule to bind with oxygen, tetrahedral

Question 13

substrate

Answer 13

molecule on which enzyme acts

Question 14

enzyme substrate complex

Answer 14

when enzyme combines with substrate

Question 15

competitive inhibitor

Answer 15

binds to active site, prevents substrate fitting

Question 16

non-competitive inhibitor

Answer 16

fits into allosteric site, distorts shape of active site so substrate can no longer fit

Question 17

fraenkel and conrat

Answer 17

showed rna can be transforming principle in viruses

Question 18

franklin, watson and crick

Answer 18

worked out structure of dna, established it was a double helix

Question 19

adenine and guanine

Answer 19

purine bases

Question 20

bond between nucleotides

Answer 20

phosphodiester

Question 21

genetic code is universal

Answer 21

same in all living things

Question 22

triplet code

Answer 22

three bases code for one amino acid

Question 23

nitrate ions

Answer 23

make dna and amino acids

Question 24

calcium ions

Answer 24

form calcium pectate for middle lamellae

Question 25

phosphate ions

Answer 25

make adp and atp

Question 26

maltose

Answer 26

made of two alpha glucose

Question 27

lactose

Answer 27

made of alpha and beta glucose

Question 28

cellulose

Answer 28

made of beta glucose, alternate inverted

Question 29

energy release of starch

Answer 29

mix of quick and slow due to mix of amylose and amylopectin

Question 30

energy release of amylopectin

Answer 30

fast because side chains of glucose easily broken off for respiration

Question 31

properties of enzyme

Answer 31

globular proteins that act as catalysts, alter rate without being changed themselves, can be reused

Question 32

catabolic enzyme

Answer 32

puts strain on substrate, makes it easier to break bond

Question 33

meselsohn and stahl

Answer 33

proved replication is semi conservative

Question 34

amylose

Answer 34

alpha glucose, 1-4 glycosidic bonds

Question 35

hexose

Answer 35

6 carbon sugar eg glucose, fructose, galactose

Question 36

pentose

Answer 36

5 carbon sugar eg ribose, deoxyribose

Question 37

benedict's test for reducing sugars

Answer 37

mix and heat in water bath - blue to green to orange to brick red

Question 38

reducing sugars

Answer 38

all monosaccharides, lactose, maltose

Question 39

bond in a triglyceride

Answer 39

ester

Question 40

bond between two amino acids

Answer 40

peptide in condensation reaction

Question 41

primary structure

Answer 41

amino acids join to form polypeptide - polymerisation

Question 42

secondary structure

Answer 42

polypeptide chain folds to form alpha helix/beta pleated sheet - held by hydrogen bonds

Question 43

quaternary structure

Answer 43

polypeptides link to form large complex molecules

Question 44

fibrous protein

Answer 44

collagen

Question 45

structure of collagen

Answer 45

three long parallel polypeptide alpha chains in triple helix structure joined by cross links to form fibres

Question 46

activation energy

Answer 46

minimum amount of energy needed to start a reaction

Question 47

active site

Answer 47

functional part of the enzyme

Question 48

anabolic enzyme

Answer 48

aligns molecules for reaction

Question 49

end product inhibition

Answer 49

end product of metabolic pathway binds to part of first enzyme in pathway - not active site

Question 50

miescher

Answer 50

isolated nuclei and discovered chemical we call dna

Question 51

briggs and king

Answer 51

removed/added nuceli to egg cells - showed that you need the nucleus for an embryo to develop

Question 52

griffiths and avery

Answer 52

Used bacteria etc and established that DNA is transforming principle

Question 53

hershey and chase

Answer 53

used viruses to confirm that dna is transforming principle

Question 54

degenerate code

Answer 54

often third base is irrelevant

Question 55

dna helicase

Answer 55

breaks hydrogen bonds between two strands

Question 56

dna polymerase

Answer 56

links up nucleotides along template strand

Question 57

dna ligase

Answer 57

catalyses formation of phosphodiester bonds