DNA to Protein

Question 1

By what process does DNA become RNA?

Answer 1

transcription

Question 2

By what process does RNA become protein?

Answer 2

translation

Question 3

Give the difference between a nucleotide and nucleoside.

Answer 3

nucleotide contains phosphate group

Question 4

Is the 5’ or the 3’ the OH group?

Answer 4

3’

Question 5

What is the 5’?

Answer 5

triphosphate

Question 6

What end are nucleotides added to, 5’ or 3’?

Answer 6

3’

Question 7

How does ZDV work?

Answer 7

because viralreverse transcriptase has higher affinity for ZDV than human DNA polymerases

Question 8

Is DNA replication conservation or semi-conservation?

Answer 8

semi

Question 9

What unwinds the helix?

Answer 9

helicase

Question 10

What synthesises the RNA primer needed?

Answer 10

primase

Question 11

Does DNA polymerase have endo or exonuclease activity?

Answer 11

exonuclease activity

Question 12

In RNA, what are the local stretches of intramolecular base-pairing which may exist?

Answer 12

stem loops

Question 13

To what end of tRNA is a specific amino acid added?

Answer 13

3’

Question 14

What kind of structure do tRNA molecules have?

Answer 14

distinct three-dimensional structure
When flattened into two dimensions:
cloverleaf structure

Question 15

What are the 3 types of RNA polymerase and which makes all mRNA?

Answer 15

Pol 1, 2 and 3

Pol 2 makes all mRNA

Question 16

Describe the steps of transcription.

Answer 16

RNA polymerase binding
(detection of initiation sites (promoters) on DNA
requires transcription factors)
DNA chain separation
(local unwinding of DNA
to gain access to the nucleotide sequence)
Transcription initiation
(selection of the first nucleotide of the growing RNA)
Elongation
(addition of further nucleotides to the RNA chain)
Termination
(release of finished RNA)

Question 17

Where is the TATA box present?

Answer 17

present about 25 nucleotides before the transcriptional start (-25)

Question 18

What is TIIFD?

Answer 18

TFIID is a general transcription factor

required for all Pol II transcribed genes

Question 19

What does TBP do?

Answer 19

recognise TATA box
introduce kink
Provides a landing platform for further transcription factors and for RNA polymerase

Question 20

What occurs in transcription termination?

Answer 20

Newly synthesised RNA makes a stem-loop structure
followed by a stretch of Us
A specific enzyme cleaves the (now finished) RNA
RNA is released
polymerase dissociates

Question 21

Where are steroid receptors?

Answer 21

in cell cytoplasm

Question 22

How are steroids transported in the blood?

Answer 22

bound to albumin or specific transport proteins

Question 23

What are the types of CHROMOSOMAL mutation?

Answer 23

deletions
duplications
inversions
translocations

Question 24

What do free ribosomes in the cytosol make proteins destined for?

Answer 24

cytosol
nucleus
mitochondria
translocated post-translationally

Question 25

What do bound ribosomes on the rough endoplasmic reticulum make proteins destined for?

Answer 25

``` plasma membrane ER Golgi apparatus secretion translocated co-translationally ```

Question 26

Where do Post-translational modifications occur?

Answer 26

ER and golgi

Question 27

Where do formation of disulfide bonds and | folding and assembly of multisubunit proteins occur?

Answer 27

ER

Question 28

What is I-cell disease?

Answer 28

inherited recessive disorder of protein targeting