nucleotides and nucleic acids

Question 1

describe DNA

Answer 1

double stranded
genetic code makes proteins
deoxyribose sugar

Question 2

describe RNA

Answer 2

single stranded
3 types of RNA all make proteins
ribose sugar

Question 3

what are the 3 types of RNA

Answer 3

mRNA
tRNA
ribosomal

Question 4

what is the monomer of RNA and DNA called

Answer 4

nucleotides

Question 5

describe the structure of a nucleotide

Answer 5

pentose sugar
organic nitrogenous base
phosphate group

Question 6

what are the bases of DNA

Answer 6

A, T, C, G

Question 7

what is the base ‘A’ called

Answer 7

adenine

Question 8

what is the base ‘t’ called

Answer 8

thymine

Question 9

what is the base ‘C’ called

Answer 9

cytosine

Question 10

what is the base ‘G’ called

Answer 10

guanine

Question 11

what are the bases of RNA

Answer 11

A, U, G, C

Question 12

what are the 2 purines

Answer 12

A and G

Question 13

what is a purine

Answer 13

larger, double ring bases

Question 14

what are the 3 pyrimidines

Answer 14

C, T, U

Question 15

what is a pyrimidine

Answer 15

smaller, single ring bases

Question 16

how do nucleotides join

Answer 16

condensation reaction

Question 17

what is the polymer of nucleotides called

Answer 17

polynucleotide

Question 18

what are the bonds between the phosphate group and the sugar of a nucleotide called

Answer 18

phosphodiester bond

Question 19

why is the bond between nucleotides referred to as a 3’ 5’ bond

Answer 19

the carbon 3 bonds with carbon 5

Question 20

what bond bonds the helix structure of DNA

Answer 20

hydrogen bonds

Question 21

how many bonds are between A and T

Answer 21

2 hydrogen bonds

Question 22

how many bonds are between C and G

Answer 22

3 hydrogen bonds

Question 23

what does anti-parallel mean

Answer 23

one strand is flipped upside down so the bases can pair in the middle

Question 24

give 4 reasons why the structure of DNA is good

Answer 24

coiled makes it compact
specific sequence gives a genetic code
double stranded makes it more stable
double stranded structure makes it easy for replication

Question 25

DNA extraction practical: why do you grind the sample with a mortar and pestle

Answer 25

to break down the cellulose cell wall

Question 26

DNA extraction practical: why do we mic the sample with detergent

Answer 26

to break down the cell membrane and the nuclear membrane

Question 27

DNA extraction practical: why do you add salt

Answer 27

takes water away from DNA

Question 28

DNA extraction practical: why do you add protease enzyme

Answer 28

break down histone proteins that DNA is wrapped around

Question 29

DNA extraction practical: why do you add a layer of alcohol on top of the sample

Answer 29

causes the DNA to precipitate out of solution

Question 30

give 3 reasons why need ATP

Answer 30

synthesis transport movement

Question 31

draw the structure of ATP

Answer 31

adenine ribose sugar 3 phosphate

Question 32

what is the product after ATP is hydrolysed

Answer 32

ADP, phosphate and energy

Question 33

how and where is ATP made in cells

Answer 33

mitochondria aerobic respiration

Question 34

give 4 ways that make ATP a good energy source

Answer 34

fairly small water soluble (can move across membrane) releases a small amount of energy (just enough for cellular reactions) easily re-made

Question 35

when does DNA need to replicate itself

Answer 35

mitosis or meiosis

Question 36

why does DNA need to replicate itself

Answer 36

this is to make enough DNA to be shared amount the new daughter cells

Question 37

describe the method of DNA replication

Answer 37

1) double helix had to unwind and separate exposing the bases by hydrogen bonds breaking using the enzyme DNA helicase 2) free nucleotides line up next to the exposed bases by complimentary base pairing 3)new hydrogen bonds form 4) new sugar phosphate back bones are formed (phosphodiester bonds form), using the enzyme DNA polymerase

Question 38

why is DNA replication called semi-conservative

Answer 38

each new daughter molecule has an original strand and a new strand

Question 39

what makes DNA replication so accurate

Answer 39

complementary base pairing

Question 40

why does one of the strands had to be copied continuously and the other has to be copied in sections

Answer 40

DNA polymerase enzyme can only move along the DNA in one direction (3' 5')

Question 41

what is it called when the strand is copied in sections

Answer 41

okazaki fragments

Question 42

what is the name for an error in a genetic code?

Answer 42

mutations

Question 43

what is a gene

Answer 43

a specific sequence of DNA nucleotides that code for a particular sequence of amino acids

Question 44

why is mRNA called messenger RNA

Answer 44

it carries a version of the genetic code as a message to the ribosome

Question 45

why is tRNA called transfer RNA

Answer 45

transfers amino acids to the ribosome to make proteins

Question 46

why is rRNA called ribosomal RNA

Answer 46

it makes up the ribosome

Question 47

where are proteins made

Answer 47

ribosome/ RER

Question 48

what are the 2 stages of protein synthesis

Answer 48

transcription and translation

Question 49

describe the first stage of protein synthesis (transcription)

Answer 49

1) enzyme DNA helicase attaches to gene causing it to unwind, breaking hydrogen bonds and making it unwind 2) one strand is the coding and the other is the template strand 3) free nucleotides line up for complementary base pairing (U replaces T) 4) temporary hydrogen bonds form 5) RNA polymerase makes the phosphate sugar backbone 6) once the enzyme leaves the DNA molecule reform, hydrogen bonds reform

Question 50

what are introns

Answer 50

non coding gene

Question 51

what are three bases on mRNA called

Answer 51

codon

Question 52

describe what happens in translation

Answer 52

1) mRNA attaches to a ribosome 2) tRNA molecules contain 3 bases called anticodons which line up next to the codons on the mRNA by complementary base pairing 3) amino acids join by peptide bonds 4) a new tRNA molecule now leaves the ribosome leaving it's amino acid behind 5) this happens until a 'stop' codon on the mRNA is reached 6) polypeptide is then released into the polypeptide

Question 53

where will the polypeptides pass to in order to be modified

Answer 53

Golgi apparatus

Question 54

what does it mean when the code is degenerate

Answer 54

there are more possible triplet codes than there are amino acids

Question 55

what is the 'start' codon called

Answer 55

AUG

Question 56

what does AUG code for

Answer 56

methionine