ppqs

Question 1

Define universal, non-overlapping and degenerate.

Answer 1

universal - same codon alwaus codes for same aa

non over;apping - one base is only part of one codon and isnt read more than once

degenerate - more than one codon codes for each aa

Question 2

describe how a quaternary proetin is formed from its monomers

Answer 2

1. aa joined by peptide bonds
2. by condensation reactions
3. secondary structure formed by h bonding
4. tertiary struture formed by interactions between r groups
5. quat structure contains more that one polypeptide chain

Question 3

describe the structure of dna and the structure of a chromosome

Answer 3

1. polynucleotide
2. consists of deoxyribose, phosphate and nitrogenous base
3. phosphodiester bonds
4. dna double helix held by hydrogen bonds
5. h bonds between adenine and thyamine and cytosine and guanine
6. dna associated with histones
7. chrom consits of 2 chromatids joined at centromere

Question 4

describe and expalin the other processes (not mutation) that result in increases in genetic variation within a species

Answer 4

1. idependant assortment of homog chroms
2. crossing over between homog chroms
3. random fertilisation of gammetes
4. produces new combs of alleles

Question 5

describe how the scientist will use info from the colorimter and her calibration curve to determine the po2 in a smaple of blood

Answer 5

• measure light apsorption/transmission
• interpolate/draw line to curve then to po2

Question 6

expalin how a chrom mutation in the second meitic div could result in an extra chrom

Answer 6

• chromatids do not separate
• nondysjuction

Question 7

outline the similarities in and the differences between the structures of chloroplasts and mitichondria

Answer 7

sims
- double memb
- contain circ dna
- contain ribs

diffs
- grana v cristae
- stroma v matrix
- chlorophyll v no chlororphyll
- starch grains v no

Question 8

give 2 types of mol from which a rib is made

Answer 8

1. rna
2. protein

Question 9

describe how would remove large organelles from suspension of cell contents

Answer 9

• use centrifuge at low speed
• large dense organelles removed in first pellet

Question 10

describe importance of high heat capacity to orgs and latent heat of vapourisation

Answer 10

-buffers change in temp

• provides a cooling affect by evap

Question 11

3 marker on cohesion tension theory

Answer 11

• evap/transpiration
• tension created moves water upwards
• cohesion maintains column of water (due to h bonds between water mols)

Question 12

describe 2 functions of bile salts

Answer 12

• emulsify lipids/fats
• inc sa for inc lipase activity
• form micelles

Question 13

describe how an antitoxin antibody would be digested

Answer 13

• peptide bonds hydrolysed
• endopeptidases break internal pep bonds
• exopeptidases break terminal pep bonds
• dipeptidase break dipeptides to aa