Week 11 Flashcards
T/F:
DNA is chemically homogenous, proteins are chemically heterogenous
True
What is the proteome?
The proteins expressed by a genome at any one time
T/F:
Cells respond to the environment by changing their genome not proteome
False
Otherway round
What is a PTM?
Post translational modification
Additions or subtractions to translated proteins that can alter the chemical structure of a protein and therefore modify its function
How many different PTMs are possible at different sites in the protein?
6
Therefore 720 possible combinations of gene products
What are the two major classes of PTMs?
Enzymatic vs non-enzymatic
Give two examples of non-enzymatic PTMs
Oxidation of proteins in the presence of reactive oxygen species
Deamidation
Give some examples of enzymes involved in enzymatic PTMs
Kinases/phosphotases
Acetyltransferases/Acetylases
Methyltransferases/methylases
O-GlcNAc tranferase/O-GlcNAcase
Does a kinase of phophatase remove a phosphate group?
Kinase= adds a phosphate Phosphotase= removes phosphate group
Which type of enzymatic PTM acts as a ‘switch’
Kinase/phosphatase
T/F:
Phosphorylation is rapid, coordinated and easily reversible
True
Which two enzymes are involved in glucose production in terms of phosphorylation?
Glycogen synthase and Glycogen phosphorylase
T/F:
Phosphorylation inhibits glycogen phosphorylase and activates glycogen synthase
False
Other way round
In what ways can PTMs alter protein structure and interactions?
Hydophobicity interactions
Charge-charge interactions
Hydrogen-bond interactions
What happens to protein function when PTMs alter charge-based interactions?
Inhbitis ability of the enzyme to bind to its structure and vice versa
