M6 Readings

Question 1

Amine Hormone

Answer 1

aa with modified group

typically modified such that a –COOH, (carboxyl group) is removed, whereas the −NH3+ (amine group) remains
synthesized from the amino acids tryptophan or tyrosine

Question 2

Peptide hormone

Answer 2

short chain of linked aa

Question 3

Protein Hormone

Answer 3

long chain of linked aa

Question 4

Steroid Hormone

Answer 4

derived from lipid cholesterol
hydrophobic
must travel to their target cell bound to a transport protein
longer half-life than amino acid–derived hormone

Question 5

Receptor Tyrosine Kinase Pathway

Answer 5

1. Insulin receptor binds insulin and autophosphorylated
2. Insulin receptor phos. IRS-1 on Tyr
3. SH2-domain bind to P-Tyr
   Sos binds to Grb2, then to Ras-lead to GTP binding on Ras
4. Active Ras binds and activates Raf-1
5. Raf-1 phos. MEK on 2 Ser
   Active MEK phos. ERK on The and Tyr
6. ERK move to nucleus and phos nuclear TFs
7. Phos. Elk1 joins SRF to stim transcription an translation

Question 6

PIP3 branching signalling

Answer 6

1. IRS-1 phos by insulin receptor activating PI3K by binding to its SH2 domain
   PI3K converts PIP2 to PIP3
2. PKB bound to PIP3 phos by PDK1
   PKB phos GSK3 on Ser (inactive)
3. GSK3 cannot convert glycogen synthase to inactive form by phos, so GS remains active
4. Glycogen synthesis accelerated
5. PKB stim movement of glucose transporter (GLUT4) from internal vesicles to plasma mem, increasing glucose uptake