DNA Structure

Question 1

Polymers: Proteins
Nucleic Acid
Monomers?

Answer 1

Amino Acid

Nucleotide

Question 2

3 components of DNA:

Answer 2

Sugar (5 C’s)
Bases (N-rich)
Phosphate

Question 3

Linked with which bond?

Answer 3

Phosphodiester Bond

Question 4

5’ means what?

Answer 4

5 Prime end of DNA

Question 5

Name pyrimidines:

Answer 5

Cytosine
Thymine
Uracil

Question 6

Name Purines

Answer 6

Adenine

Guanine

Question 7

A forms which bond with T

Answer 7

Hydrogen bond

Question 8

1000 base pairs =

1,000,000 base pairs =

Answer 8

Kilobase (kb)

Megabase (Mb)

Question 9

All genetic material in a cell is called it’s

Answer 9

Genome

Question 10

Prokaryotic genomes (bacterial):
Genome with no nucleus in called...
Small circles of DNA called...
Diploid or haploid?
shape of chromosome

Answer 10

Nucleoid
Plasmids
Haploid
Typically circular

Question 11

Eukaryotics genomes:

Diploid or haploid

Answer 11

Mostly Diploid

Question 12

Position of constriction on chromosome is called

Answer 12

Centromere

Question 13

End of chromosome called

Answer 13

Telomere

Question 14

DNA functions (2)

Answer 14

DNA replication

Gene expression

Question 15

Repliction of DNA happens when?

Answer 15

before cell division, in interphase

Question 16

How many daughter cells produced in:
Mitosis
Meisois

Answer 16

2 (2n)

4 (n)

Question 17

Semi-conservative means:

Answer 17

half old and half new

Question 18

Which enzyme synthesises leading strand continuously

Answer 18

DNA polymerase

Question 19

What does RNA polymerase do?

Answer 19

synthesis short RNA primer, which is extended by DNA polymerase

Question 20

DNA polymerase digests ….. and replaces it with

Answer 20

RNA primer

DNA

Question 21

What does DNA ligase do?

Answer 21

joins together discontinuous fragments on lagging strand

Question 22

DNA polymerase can only work when

Answer 22

a nucleotide is present with a free reactive tail (3’)

Question 23

polymerisation means

Answer 23

joining together of nucleotides

Question 24

which direction does DNA polymerase polymerise?

Answer 24

5’ to 3’

Question 25

What is a gene?

Answer 25

Segment of DNA molecule nucleotide sequence producing a product

Question 26

2 key stages of gene expression:

Answer 26

Transciption | Translation

Question 27

Transcription= | Translation=

Answer 27

synthesis of an RNA copy of a gene | Synthesis of polypeptide by decoding genetic message within RNA copy

Question 28

Translation happens where in eukaryotic cell

Answer 28

cytoplasm

Question 29

Translation cant start until what is made

Answer 29

mRNA

Question 30

Transfer RNA size and function

Answer 30

Small, transports amino acids to site of protein synthesis

Question 31

Ribosomal RNA size and function

Answer 31

variable, combines with proteins to form ribosomes

Question 32

Messenger RNA size and function

Answer 32

Variable, directs amino acid sequence of proteins

Question 33

Promoters are where sites of what

Answer 33

where transcription starts, DNA sequences that bind RNA polymerase, each gene has own promoter

Question 34

What hapens at terminator site?

Answer 34

where transcription stops, RNA polymerase leaves DNA

Question 35

Non-coding DNA is called

Answer 35

Introns

Question 36

Coding DNA is called

Answer 36

exons

Question 37

RNA processing 3 steps:

Answer 37

Splicing Capping Tailing

Question 38

RNA processing step order and meaning of each step:

Answer 38

Splicing- introns removed, exons spliced together capping- cap structure added to 5' end Tailing- String of A bases added 3' end

Question 39

Ribosome:

Answer 39

protein-making gactory that reads mRNA message and carries out the messages instructions, made up of rRNA & ribosomal proteins

Question 40

The genetic code:

Answer 40

Message carried by mRNA

Question 41

tRNA function:

Answer 41

Carrier molecules of amino acids to ribosome

Question 42

tRNA structure:

Answer 42

Single strand of RNA secondary structure is cloverleaf structure consists of base paired 'stems' & unpaired 'loops' At 3' end is attatchment point for amino acid 3 bases (anticodon) base pair with mRNA (codon)

Question 43

3 stages of translation:

Answer 43

Initiation Elongation Termination

Question 44

Stages of initiation (1st stage of translation)

Answer 44

Ribosome recognises & attaches to mRna, Ribosome translocates along mRNA looking for start codon, initiator tRNA carries methionine and binds at P site, anitcodon arms match up with complementary sequence on codon of mRNA, Another tRNA enters at A site and peptide bond formed between 2 bound tRNA amino acids.

Question 45

Elongation (2nd stage of translation)

Answer 45

ribosome translocates along one codon along mRNA uncharged tRNA leaves rivosome via exit E ribosomes receive charged tRNA dictated by each codon ribosome continues to translocate along mRNA 5' to 3'

Question 46

Termination (3rd stage of translation)

Answer 46

Ribosome continues along mRNA till stop codon no tRNA enters stop site Release factor proteins enters instead resulting in translation termination translation complex dissociates polypeptid is released and folded to become mature protein.