Hormonal Regulation (Lecture 35)

Question 1

signalling cascade if gluconeogenesis in conditions of fasting

Answer 1

glucagon =>PKA => pCREB => DNA => INCREASE gluconeogenesis

Question 2

bile is synthesized via

Answer 2

FXR and CYP7-alpha-1

Question 3

key factors in fructose induced lipogenensis

Answer 3

SREBP
ChREBP
PGC1-beta

increased magic enzyme
increased pyruvate dehydrogenase
increased fatty acid sytnhase

Question 4

the circadian clock controls transcription via

Answer 4

levels of NAD+

AMP/ATP vis AMPK

transcription factos Bmal1/Clock

Question 5

principles of hormone functions (4)

Answer 5

SPECIFICITY: one ligand, one receptor

AMPLIFICATION: activation pop downstream effectors

DURATION OF EFFECT: short term regulation (phosphorylation), long term- activation/repression of transcription

DESENSITIZATION/ADAPTATION: activation of negative feedback signal

Question 6

gated ion channel

Answer 6

opens and closes in response to concentration of ligand or membrane potential

ATP-gates K+ channel in beta pancreatic cells

Question 7

receptor enzyme

Answer 7

ligand binding to extracellular domain stimulates enzyme activity ion the intracellular domain

insulin receptor

Question 8

serpentine receptor

Answer 8

external ligand binds to receptor which will activate an intracellular GTP-binding protein. this regulates an enzyme that generates an intracellular second messenger

Question 9

steroid receptor

Answer 9

steroid biding to a nuclear receptor protein allows the receptor to regulate the expression of specific genes

estrogen/ thyroid hormone receptors

Question 10

receptor with no intrinsic enzyme activity

Answer 10

ligand interacts with cytosolic protein kinase, which activates a gene regulating protein, thus resulting in a change in gene expression

leptin receptor