2D: Gene expression

Question 1

Gene expression

Answer 1

The process of reading the information stored within a gene to create a functional product, typically a protein.

Question 2

Transcription

Answer 2

The process whereby a sequence of DNA is used as a template to produce a complementary sequence of mRNA.

Question 3

Precursor messenger RNA

pre-mRNA

Answer 3

The immediate product of transcription of a DNA sequence. Requires modifications before it can undergo translation.

Question 4

Messenger RNA (mRNA)

Answer 4

Molecules that are produced during transcription and carry genetic information from the nucleus to the ribosomes.

Question 5

Translation

Answer 5

The process where an mRNA sequence is read to produce a corresponding amino acid sequence to build a polypeptide.

Question 6

Transfer RNA (tRNA)
RNA

Answer 6

RNA molecules that recognizes specific codons on the mRNA strand and adds the corresponding amino acid to the polypeptide chain during protein synthesis.

Question 7

Ribosomal RNA (rRNA)

Answer 7

RNA that is a key structural component of ribosomes,

which assemble proteins.

Question 8

Enzyme

Answer 8

an organic molecule, typically a protein, that catalyses (speeds up) specific reactions.

Question 9

Transcription factor

Answer 9

proteins that bind to the promoter region and control the functioning of RNA polymerase.

Question 10

Promoter Region

Answer 10

The sequence of DNA to which RNA polymerase binds. Denotes the starting position and direction of transcription

Question 11

RNA polymerase

Answer 11

The enzyme responsible for constructing a pre-mRNA sequence from a DNA sequence during transcription.

Question 12

Template strand

Answer 12

The strand of DNA transcribed by RNA polymerase to produce a complementary pre-mRNA strand.

Question 13

Coding strand

Answer 13

The strand of DNA not transcribed by RNA polymerase, containing an identical sequence to the mRNA strand produced (except thymine is replaced with uracil in mRNA).

Question 14

Termination sequence

Answer 14

A sequence of DNA that signals the end of transcription.

Question 15

Ribosome

Answer 15

An organelle made of rRNA and protein that is the site of protein synthesis. Can be free in the cytosol or attached to the rough endoplasmic reticulum.

Question 16

5’ methyl-G cap

Answer 16

A molecule added to the 5’ end of pre-mRNA during RNA processing.

Question 17

Poly-A tail chain

Answer 17

A chain of adenine nucleotides added to the 3’ end of pre-mRNA during RNA processing.

Question 18

Introns

Answer 18

Non-coding regions of DNA that do not code for proteins. They are spliced out during RNA processing.

Question 19

Splicing

Answer 19

Process where introns are cut out of a pre-mRNA molecule, and exons are joined together.

Question 20

Exons

Answer 20

Regions of DNA that code for proteins and are not spliced out during RNA processing and are transcribed and translated into the final protein

Question 21

Spliceosome

Answer 21

The enzyme that removes introns from the pre-mRNA molecule and joins exons together during RNA processing.

Question 22

Alternative splicing

Answer 22

The process where different exons may be spliced, resulting in a single gene producing multiple different mRNA strands.

Question 23

Codon

Answer 23

The sequence of three nucleotides in mRNA coding for

one amino acid.

Question 24

Start codon

Answer 24

The sequence of three nucleotides in mRNA that signals the start of translation.

Question 25

Anticodon

Answer 25

The sequence of three nucleotides on a tRNA molecule that recognises a specific sequence of three nucleotides (codon) on an mRNA strand.

Question 26

Peptide bond

Answer 26

The chemical bond linking two amino acids.

Question 27

Condensation reaction

Answer 27

A reaction where two monomers join to form a larger molecule, producing water as a by-product.

Question 28

Stop codon

Answer 28

The sequence of three nucleotides in mRNA that signals the end of translation.

Question 29

Exocytosis

Answer 29

A type of bulk transport that moves large substances out of a cell.