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Flashcards in DNA to protein Deck (85)
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1

nucleoside =

base and sugar

2

nucleotide =

nucleoside and phosphate group

3

what is the difference between ribose and deoxyribose?

on C2 of ribose there is an OH instead of an H

4

what are the two purines?

adenine and guanine

5

what are the three pyramidines?

uracil, thymine and cytosine

6

in polymerisation a phosphodiester bond is formed between a free 3’ __ group and a 5’ ________

A phosphodiester bond is formed between a free 3’ OH group and a 5’ triphosphate

7

polymerisation releases 2 __ enegy bonds

high

8

new nucleotides are only added to a free _’ end

3

9

analogues of thymidine (ZDV=AZT=retrovir) can be used as drugs. The analogue is incorporated into the growing viral DNA
Lacks _’ __ group, therefore, chain elongation is terminated

Is incorporated into the growing viral DNA
Lacks 3’ OH group, therefore, chain elongation is terminated

10

the nucleotide analogue mechanism only works because viral _____ ______ has higher affinity for ZDV than human DNA polymerases

reverse transcriptase

11

Replication is semi-______

conservative

12

replication is catalysed by ________

DNA polymerase

13

DNA polymerase requires a ____ primer to start replication

RNA

14

in eukaryotes Replication starts simultaneously at several points in the genome
and is bidirectional, what is the advantage of this?

ensures that replication can be finished in a reasonable time

15

the leading strand template runs from __' to __'

5 to 3

16

the lagging strand template runs from __' to __'

3-5

17

which enzyme synthesises the primer for replication?

primase

18

DNA ______ unwinds the double helix

helicase

19

after the okazaki fragments have been generated the ____ are degraded and filled in by DNA -_______

primers, polymerase

20

DNA polymerase has 3’ → 5’ _______ activity

exonuclease which removes incorrect nucleotide

21

RNA is usually ___ stranded with local stretches of _______ base-pairing

single, intramolecular

22

what are the three main classes of RNA

1. ribosomal RNA
2. transfer RNA
3. messenger RNA

23

what are the stable RNAs?

ribosomal and transfer

24

what is the function of ribosomal RNA?

combines with proteins to form ribosomes where protein synthesis takes place

25

what is the function of transfer RNA?

carries the amino acids to be incorporated into the protein

26

what is the function of messenger RNA?

carries the genetic information for protein synthesis

27

RNA contains __ instead of thymine

uracil

28

rRNA has __ units to it

4

29

in tRNA specific amino acid is attached to the _’ end
depends on _______ sequence

Specific amino acid is attached to the 3’ end
depends on anticodon sequence

30

RNA is made by ___ _______

RNA polymerases