1) Unit 1 - Proteomics

Question 1

What is the genome, proteome and transcriptome

Answer 1

Genome: all the hereditary information encoded in DNA

proteome: all the proteins expressed by the genome
transcriptome: all the possible mRNA expressed by the genome

Question 2

Give these in the order from smallest to largest:

genome, proteome and transcriptome

Answer 2

genome > transcriptome > proteome

Question 3

Why is the proteome larger than the genome?

Answer 3

alternative splicing and post transnational modification

Question 4

why are not all genes expressed as proteins in a particular cell?

explain the benefit of this and give an example

Answer 4

due to gene expression.

benefit: makes cell more energy efficient producing only essential proteins
example: promoter gene for keratin in a muscle cell is switched off as it is not needed for the muscle to perform its function.

Question 5

name and describe the two types of post translational modification

Answer 5

•addition of a chemical group that is not a protein or amino group also known as a prosthetic group
e.g. heme in hemoglobin

• cleavage - the cutting of a polypeptide chain

Question 6

give 2 examples of other molecules that can be added to a polypeptide chains

Answer 6

phosphates and carbohydrates

Question 7

describe alternative mRNA splicing, why is it beneficial

Answer 7

This is the process where different regions of a gene can be treated as introns and exons depending on the protein being made.

This allows more than one protein to be made from a single gene