1.2.1 proteins - the proteome

Question 1

what is the proteome

Answer 1

the proteome is the entire set of proteins expressed by a genome

Question 2

is the proteome larger than the number of genes?

Answer 2

yes

Question 3

is the proteome smaller than the number of genes?

Answer 3

no

Question 4

why is the proteome larger than the number of genes - particularly in eukaryotes?

Answer 4

because more than one protein can be produced from a single gene as a result of alternative RNA splicing

Question 5

are all genes expressed as proteins in a particular cell type

Answer 5

no

Question 6

what are non-coding RNA genes

Answer 6

they are genes that do not code for proteins

Question 7

what do non-coding RNA genes include

Answer 7

those that are transcribed to produce tRNA, rRNA, and RNA molecules that control the expression of other genes

Question 8

can the set of proteins expressed by a given cell type can vary over time and under different conditions

Answer 8

YES

Question 9

what are some factors that affect the set of proteins expressed by a given cell type

Answer 9

• metabolic activity of the cell
• cellular stress
• the response to signalling molecules
• diseased versus healthy cells