Transcription/translation

Question 1

How many hydorgen bonds between G-C

Answer 1

3

Question 2

How mnay hydrogen bonds between A-T

Answer 2

2

Question 3

what is at the 5’ end?

Answer 3

Phosphate group

Question 4

What is at the 3’ end?

Answer 4

OH group

Question 5

What are the two strands of DNA?

Answer 5

Antiparallele

Question 6

Which way are new dna or rna molecules ALWAYS synthesised?

Answer 6

5’-3’

Question 7

promoter sequence

Answer 7

Region at the start of the gene

Question 8

terminator seqeunce

Answer 8

stop signal to indicate end of the gene

Question 9

structural genes

Answer 9

code for proteins that are involved in structre and function

Question 10

introns

Answer 10

non-coding sections within a gene

Question 11

exons

Answer 11

coding sections within a gene

Question 12

What is transcrpition?

Answer 12

Synthesis of RNA from a DNA template

Question 13

What is translation

Answer 13

Synthesis of a polypeptiide/protein whose specfiic seqeunce of amino acids is determined by the mRNA base sequence.

Question 14

What does a three base sequence of DNA code for?

Answer 14

Triplet

Question 15

What des a three base sequence m-RNA code for

Answer 15

codon

Question 16

What does a three base sequence of tRNa code for

Answer 16

anticodon

Question 17

What are introns and exon

Answer 17

The coding regions of genes

Question 18

what happens to exons?

Answer 18

They are both transcribed and translated

Question 19

What happens to introns

Answer 19

they are only transcribed.

Question 20

Do bacteria posses introns?

Answer 20

no

Question 21

What are flanking regions?

Answer 21

regions of DAN on either side of the cooding region of a gene

Question 22

What are the two flanking regions

Answer 22

Upstream region

Downstream Regiono

Question 23

Upstream region

Answer 23

Section of DNA befre the start of the coding region (includes promotor sequence

Question 24

Downstream Region

Answer 24

Located after the end of the coding region of a gene. Includes the end transcrption signal which terminates transcription

Question 25

What is a promotor?

Answer 25

Control region of upstream region that exists to switch gene on or off

Question 26

What do promotors have in them

Answer 26

TATA box

Question 27

What initiates transcription?

Answer 27

RNA polymerase binds to the promoter region

Question 28

What are promotors like in prokayrotes

Answer 28

- Two essential sequences - One is recognised by RNA polymerase - Second is that TATA box where DNA begins to seperate

Question 29

What is DNA transcribed into

Answer 29

mRNA

Question 30

Why is it that an organism must make a mobile copy of genetic instructuions?

Answer 30

DNA cannot move outside of the nucleus

Question 31

where does transcription occue

Answer 31

Euk-Nucleus | Prok-Cytoplasm

Question 32

Explain the steps in transcription

Answer 32

1. RNA polymerase attaches to promotor region (upstream region) 2. DNA unwound by RNA polymerase, breaks weak hydrogen bonds now unpaird bases are exposed 3. RNA polymerase contructs pre mRNA by collecting free RNA nucleotides 4. DNA reforms to make a double helix

Question 33

What does pre-mRNA contain?

Answer 33

Introns and exons

Question 34

What direct is RNA transcript assembeled in?

Answer 34

5'-3'

Question 35

Explain post transcription modification

Answer 35

Enzymes cut out introns from the pre-mRNA and the remaining exons are joined together and a methly cap is adde and a poly-A-tail to the other.

Question 36

Where does the mRNA go?

Answer 36

Leaves the nucleus via a nuclear pore to perform its functiion at the ribosomes.

Question 37

What is a codon

Answer 37

three base sequence of mRNA

Question 38

What number of bases is mRNA translated in

Answer 38

3

Question 39

What is the start codon for translation?

Answer 39

AUG

Question 40

When does translation end?

Answer 40

The entire protein is coded for by many codons untill a stop codon is reached

Question 41

Where are the amino acids needed to make up the protein found?

Answer 41

In the cytosol

Question 42

Explain the process of translation

Answer 42

mRNA codon is translated the tRNA with the complementary anticodon will pair with the mRNA codon via base pairs When this happens an amino acid is deposited and a peptide bind forms between the amino acid and the growing polypeptide chain

Question 43

What is a tRNA molecules

Answer 43

- coiled RNA molecules - 3-base sequneces - one end an anticodon and at the other is a region that attaches to one specfic amino acid.

Question 44

Explain gene regulation in eukaryotes

Answer 44

Cell needs to control which genes are turned off an on at any one time.

Question 45

Explain gene regulation in bacteria

Answer 45

Repressor proteins prevent the binding of RNA polymerase to keep the upstream flanking region of a gene, therefore keeping the gene turned off.

Question 46

What is an operon

Answer 46

Functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter.

Question 47

Briefly explain the operation of lac operon

Answer 47

- Bacteria use lactose as a food source - iif there is no lactose present within the cell the repressor proteinn atttaches to the operator sequence and blocks transcriiption - if lactose enters the cell then it removes the repressor protein and the RNA polymerase can bind to the promotor.

Question 48

What are homeotic genes?

Answer 48

Regulator genes that play an important role in the embryotic developemtn of vertebrates and insects.

Question 49

what can adding a double stranded RNA molecule do?

Answer 49

Cause a gene to be slienced

Question 50

How does RNA inferencing work?

Answer 50

1. Add a long dsRNA to the cell 2. Enxyme cuts it into short fragment 3. These fragments combine with particular proteins to form a RNA-induced silencing complex 4. Target mRNA broken down 5. By breaking mRNA down the protein encoded by the gene cannot be produced