Transcription

Question 1

A gene is a

Answer 1

sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specific polypeptide (protein)

Question 2

This process of protein synthesis occurs in two stages:
Transcription –

translation-

Answer 2

DNA is transcribed and an mRNA molecule is produced

mRNA (messenger RNA) is translated and an amino acid sequence is produced

Question 3

Transcription
This stage of protein synthesis occurs in the

Answer 3

nucleus of the cell

Question 4

Step 1 Part of a DNA molecule unwinds (the hydrogen bonds between the……………

which is catalysed by…

Answer 4

complementary base pairs break

Catalysed by DNA helicase, like in DNA replication

Question 5

step 2 This exposes the gene to be ………….

Answer 5

the gene from which a particular polypeptide will be produced)

Question 6

step 3 A complementary copy of the code from the gene is made by building a……..

Answer 6

single-stranded nucleic acid molecule known as mRNA (messenger RNA)

Question 7

step 4 Free activated ……… pair up (via …………bonds) with their complementary (now ………..) bases on one strand (the ………….strand) of the ‘unzipped’ DNA molecule

Answer 7

RNA nucleotides

hydrogen

exposed

Template

Question 8

step 5 The sugar-phosphate groups of these RNA nucleotides are then bonded together by the enzyme …………. to form the ………….. of the mRNA molecule

via condensation reaction

Answer 8

RNA polymerase

sugar-phosphate backbone

Question 9

step 6 When the gene has been transcribed (when …………), the hydrogen bonds between the mRNA and DNA strands ……. and the ……….. re-forms

Answer 9

the mRNA molecule is complete

break

double-stranded DNA molecule

Question 10

step 7 The mRNA molecule then leaves ……. via the ……..

Answer 10

the nucleus via a pore in the nuclear envelope