Nucleic Acid

Question 1

what structures are made from DNA and where are they found

Answer 1

double helix structures (chromosones) are made from DNA and are found in the nucleus

Question 2

what type of protein is also contained in a chromosone and what does it do

Answer 2

histones
holds DNA during replication

Question 3

what are the monomers of DNA and RNA called

Answer 3

nucloetides

Question 4

what reaction joins the components of a nucleotide together

Answer 4

condensation reaction to form phosphodiester bonds

Question 5

name the 4 nitrogenous bases in DNA

Answer 5

cytosine
guanine
thymine
adenine

Question 6

name the 4 nitrogenous bases in RNA

Answer 6

cytosine
guanine
adenine
uracil

Question 7

what is one side of a chromosone called

Answer 7

a chromotid

Question 8

what two things make up a chromotid

Answer 8

DNA tightly coiled round a histone

Question 9

what 3 parts make up DNA

Answer 9

phosphate group
deoxyribose sugar
nitrogous base

Question 10

what are the differences between DNA and RNA

Answer 10

DNA
double strand
A,T,C,G
dexoyribose

very stable
contains hereditary material

RNA
single strand
A,U,C,G
ribose

used in protien synthysis
short lived

Question 11

how many more oxygen does RNA have than DNA

Answer 11

1

Question 12

how many hydrogen bonds can form between base pairs

Answer 12

3 between C and G
2 between A and T

Question 13

is DNA parallel or antiparallel

Answer 13

anti parallel

Question 14

will C-G bonds or A-T bonds be stronger and why

Answer 14

C-G becuase they have more hydrogen bonds

Question 15

why is it a good thing that the DNA is very stable

Answer 15

to passes from generation to generation and rarely mutates

Question 16

why is it good that they two polynucleotide strands are linked only by hydrogen bonds

Answer 16

during replication and protein synthesis strands are easily separated

Question 17

why is it a good thing that DNA is a huge molecule

Answer 17

it can store lots of information

Question 18

why is it a good thing that DNA is coiled into a double helix with a sugar - phosphate backbone

Answer 18

the information is protected a bit within the coil

Question 19

why are base pairing good in DNA

Answer 19

allows DNA to replicate and transfer RNA as info

Question 20

what does in vivo mean

Answer 20

by a living organism (rather than a lab )

Question 21

how was the fact that DNA was hereditary material tested

Answer 21

mice were injected with harmful and safe pneumonia
both mice remained healthy
then the mice are given both types of pneumonia and they become ill

Question 22

what were the three theories that explained why the mice became ill from the two types of pneumonia

Answer 22

1. experimental error ( harmful pnemonia wasnt killed )
2. safe bacteria mutated into harmful bacteria
3. pneumonia is caused my toxins. harmful bacteria knows how to kill but is dead so cant. safe bacteria doesnt know how to kill but is alive. but this info may have been transfered to the safe pneumonia making it capable to kill

Question 23

how was theory 3 tested in pneumonia in mice

Answer 23

harmful bacteria was purified and added to safe bacteria
the substances which then became harmful was DNA because the info had been passed on in replication

Question 24

how was DNA as a hereditary material tested with a virus

Answer 24

the proteins and DNA were taken from a virus and radioactive material was attached
they both infected a bacteria
the bacteria was tested to see which one became radio active
the answer was the one with radio active DNA

Question 25

what 4 conditions must be met for DNA replication to happen

Answer 25

1 a pool of free nucleotides must be present 2 both strands of DNA must be copied as a template 3 the enzyme DNA polymerase and DNA helicase must be present 4 atp needs to drive the process

Question 26

what type of replication is it and why

Answer 26

semi conservative because one original strand remains in tact and a new complementary strand is formed

Question 27

how is the leading strand (towards the fork) replicated

Answer 27

continuously

Question 28

how is the lagging strand (away from the fork) replicated

Answer 28

discontinuously

Question 29

explain the meselson and stahl experiment

Answer 29

grew ecoli in heavy nitrogen all DNA was heavy nitrogen moved ecoli to light nitrogen so any new DNA would be light nitrogen after 1 generation bacteria and DNA was removed do another cycle and repeat the samples were spun in a centrifuge so that heavy nitrogen would fall to the bottom

Question 30

what were the results of meselson and stahls investigation

Answer 30

after first spin - 50 % heavy 50% light nitrogen after second spin - some heavy but most light

Question 31

how did meselson and stahls investigation support semi conservative replication

Answer 31

because after more spins occured the amount of light DNA increased proportionally

Question 32

what is the word equation for the conversion of ATP to ADP

Answer 32

atp - > adp + pi + energy (hydrolised)

Question 33

what is the word equation for the conversion of adp to atp

Answer 33

adp +pi -> atp (phosphorylation)

Question 34

what two organelles is atp synthesised in

Answer 34

mitrochondria chloroplast

Question 35

why is atp and immediate energy source

Answer 35

it is a universal currency it is released instantly in small amounts

Question 36

5 main biological functions of atp

Answer 36

1 lower activation energy of molecules because of the inorganic phosphate released during hydroylsis making other compounds reactive 2 metabolic processes 3 changes the shape of carrier proteins in the membrane making active transport possible 4 filaments of muscles slide past each other and shorten the muscle fibre 5 formation of lysomes

Question 37

why is glucose not a good immediate source of energy

Answer 37

it takes a while to release energy and there is a lot of waste

Question 38

hydrogen ions info

Answer 38

comes from acids breaking down high h + conc = low pH could denature enzymes

Question 39

magnesium ions info

Answer 39

creates chlorophyll

Question 40

calcium ion info

Answer 40

nerve communication releasing nurotransmitter s muscle contraction

Question 41

phosphate ion info

Answer 41

cell membrane phospholipids atp

Question 42

what does adhesion mean

Answer 42

water making hydrogen bonds with other structures

Question 43

what does cohesion mean

Answer 43

water making hydrogen bonds with water

Question 44

how do water molecules have hydrogen bonds

Answer 44

the molecules are attracted to the sligh opposite charge in the other molecules but this means bonds are broken easily

Question 45

why is waters high spesific heat capasity important

Answer 45

acts as a buffer to sudden changes in temp so stops enzymes denaturing, keeps conditions for fish stable

Question 46

why is water acting as a solvent good

Answer 46

it dissolves things so they can be transported

Question 47

why is water being transparent good

Answer 47

sea weed and photosynthesise

Question 48

why is the density of ice good

Answer 48

it is denser than water so acts as an insulator

Question 49

why is high specific latent heat of water good

Answer 49

it takes a lot of enegry to change state so helps with cooling down our bodies

Question 50

why are hydrogen bonds in water good

Answer 50

it creates surface tension and allows transport in the xylem

Question 51

where are inorganic ions found in the body

Answer 51

cytoplasm

Question 52

what is the function of iron in the body

Answer 52

production of hemoglobin in the red blood cells

Question 53

what is the function of sodium in the body

Answer 53

co transport of glucose and amino acids across the cell membrane muscle contractions nerve impulses

Question 54

Describe dna replication

Answer 54

1 dna helicase breaks hydrogen bonds 2 exposed base pairs attract new complementary bases and they try and make temporary hydrogen bonds 3 dna polymerase makes new strand 4 new phosphdiester bonds are formed 5 eventually dna separates into two strands of dna