week 4

Question 1

G protein receptor

Answer 1

Enzyme sent to second messenger

Question 2

Tyrosine kinase receptor enzyme

Answer 2

Phosphorylation is activated

Question 3

Gated ion channel

Answer 3

Opens or closes in response to concentration

Question 4

Steroids

Answer 4

Go straight into the cell and trigers changes in gene expression. Is a nuclear receptor.

Question 5

Phosphorylated (2 points)

Answer 5

• When there is a hydroxyl group on side chain (such as Serine, threonine and tyrosine)
• Activated when there is kinase activity (specific for each substrate)

Question 6

How does kinase works? (3 steps)

Answer 6

Takes ATP, adds phosphate to another protein, changes their conformation.

Question 7

Who is the major receptor of kinase?

Answer 7

The receptor itself. It gets phosphorylated. It then recruits molecules from inside the cell.

Question 8

Role of SH2 domain (1 point, 1 note)

Answer 8

Allows molecules to bind to phosphorylated residues.

NOTE: residues around the SH2 also have specificity!

Question 9

Why does molecules bind to parts of the membrane?

Answer 9

Increases the chances of encountering their “pair”. Enzymes can find their substrate more easily.

Question 10

Spatial Regulation

Answer 10

When phosphorylation occurs and molecules such as kinase are recruited to the membrane, the enzyme is bought to the substrate.
Manner of increasing probability a protein will find their “partner”.