U3A1: 2D gene expression

Question 1

gene expression

Answer 1

events that form functional gene products.

Question 2

stages of gene expression in the production of proteins:

Answer 2

dna sequence of a gene → [transcription] → pre-mrna → [rna processing] → mrna → [translation] → protein.

Question 3

process of transcription

Answer 3

proteins bind to promoter to start transcription.
rna polymerase binds to promoter, signals weak hydrogen bonds to break.
rna polymerase reads template strand.
rna polymerase uses free-floating nucleotides to make pre-mrna strand.
rna polymerase reaches termination sequence.
pre-mrna released, dna winds up.

Question 4

process of rna processing

Answer 4

methyl-guanine cap added to 5’ end. poly-adenine tail added to 3’ end. stabilises + prevents degrading.
introns spliced and exons combined via spliceosome

Question 5

process of translation

Answer 5

ribosomes bind to mrna.
mrna codons read 5’ to 3’ by trna. one side contains anticodon, one side contains amino acid.
stop codon enters final section of ribosome stopping translation.

Question 6

types of genes

Answer 6

• constitutive
• structural
• regulatory

Question 7

constitutive genes

Answer 7

always switched on and always being transcribed.

Question 8

structural genes

Answer 8

codes for any RNA/protein product except for regulatory factors.

Question 9

regulatory genes

Answer 9

involved in the controlling or expression of one or more genes.