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Biochem Exam 3 > Hormones > Flashcards

Flashcards in Hormones Deck (26):
1

Flutamide vs Faslodex?

Flutamide for male (Prostate), Faslodex for female (breast)

2

Peptide hormones stimulate what pathways (3 examples)

Adenylate cyclase
RTK's
PIP2 hydrolysis

3

Lispro is the same as

Humalog

4

Aspart is the same as

Novolog

5

Glargine equals

Lantus

6

Insulin signaling pathway

TKr phosphorylates itself and IRS
SH2 domain-containing proteins bind to receptor
PI3 Kinase activated
PK-B is activated

7

Epinephrine signaling pathway

G Protein ----> PLC -----> PIP2 --------> DAG + IP3 (-->Ca++) ------->PKC

(PKC phosphorylates Glycogen Synthase (OFF) and Glycogen Phosphorylase (Activates "A")

8

Glucagon acts via what pathway

cAMP (mediates protein kinase that phosphorylates stuff)

9

Steroid carriers

Nonspecific = Albumin
Specific = Transcortin + SHBG

10

Only ____ steroid can enter cells

free

11

3 sources for Steroid Biosynthesis

-Endogenous Synthesis
-LDL
-Cholesterol esters in cells

12

There are three pituitary hormones that play a role in regulating steroid biosynthesis. What are they and what do they do?

ACTH, LH, FSH

They activate production of:
-Synthesizing enzymes
-Cholesterol esterase
-LDL receptor

13

Major regulator of Steroid biosynthesis. How is it (itself) regulated? What does it do?

CYP11A (Cholesterol Desmolase)

Activated by phosphorylation in mitochondria

Catalyzes C-C cleavage in a method other than hydrolysis

14

Cyp21-A2 reactions (2)

Progesterone to Deoxycorticosterone
Deoxycorticosterone to Cortisol*

in Zona Fasiculata

15

Cyp11-B2 reaction

makes Aldosterone

(in Zona Glomerulosa)

16

CAH cause and effect

21 hydroxylase (Cyp21-A2) deficiency

Causes decreased cortisol production -- more steroid shunted toward sex hormone synthesis

17

Aldosterone Synthase deficiency cause and effects. What does AS normally do (biochemically)?

Deficient in CYP11-B2, which is required for hydroxylation of deoxycorticosterone at C-11B and C-18

18

Steroid receptor domains (6)

-Transcription activation ( = variable & immunogenic)
-DNA binding ( = conserved)
-NLS signal
-Transcription activation subdomain
-HSP
-Steroid part?

19

DNA binding domain properties

Two Zn+-finger motifs. One binds DNA, one dimerizes

20

Cortisol suppresses inflammation via

Phospholipase A2 inhibition

21

Steps for ACTH stimulation of cortisol synthesis

ACTH--receptor--Gprotein--Adenylate cyclase--cAMP

cAMP--PKA--Cholesterol release from lipoprotein--StAR protein** -- Side Chain cleavage enzyme -- Pregnenolone

22

What is StAR protein?

StAR = Steroid Acute regulatory protein

23

Thyroid hormone synthesis pathway

TGlobulin--(Tyr's modified by iodine in colloid)--MIT/DIT ---T3/T4

24

What gets iodinated in Thyroid hormone synthesis? By what enzyme? Where?

Tyrosine residues, by Thyroid peroxidase, in the colloid

25

Plasma T3 & T4 exist in free form?

No, bound by Thyroxin BP

26

TSH acts via what kind of receptor?

Nuclear receptor