Biochem Chapter 14 Biosynthesis of Cholesterol and Steroids

Cholesterol is removed from cell by _______

HDL

Cholesterol increase membrane fluidity at _____ temperature

Cholesterol decrease membrane fluidity at _____ temperature

low

high

_______ fatty acid chains make denser, more ordered membranes, whereas ______ fatty acids, because of “kinks” caused by the double bonds, form less ordered structures.

Saturated, Unsaturated

High cholesterol leads to response of inflammatory signal and may cause _______

atherogenesis

ABC transporter use _____ to move molecules

ATP

Ezetimibe treats hypercholesterolemia by suppressing cholesterol ______

transport

Can human synthesize cholesterol

Yes because human have Acetyl CoA which is needed for cholesterol synthesis

The first committed step in the pathway of cholesterol synthesis is the formation of ______ acid

mevalonic

The rate-limiting enzyme in the pathway is HMG-CoA ______

reductase

How many ATP and Cholesterol is needed to synthesize 1 cholesterol

36 ATP and 18 Acetyl-CoA

High PCSK ______ LDL therefore causes high ______

LDL, Cholesterol

PCSK9 prevents recycling of LDL

SREBP 1 vs 2

SREBP 1 regulates fatty acid synthesis and cholesterol efflux

SREBP 2 activates cholesterol synthesis and LDL receptor expression

Peroxisome Proliferator-Activated Receptor (PPAR) control ______ and ______ metabolism

carbohydrate, lipid

Statin is a _______ inhibitor.

HMGR

HMG Reductase

Cholestyramine lower cholesterol by

binding to bile acid

Steroidogenesis is controlled by ______ _____ monooxygenases

Cytochrome P450

Smith-Lemli-Opitz is a defect in 70dehydrocholesterol reductase causing ________

microcephaly

In the adrenal glands, the zona fasciculata and zona reticularis are places of synthesis of ______ and adrenal androgens; the outer layer (zona glomerulosa) synthesizes _______

cortisol, aldosterone

Cortisol synthesis is stimulated by ______

ACTH from pituitary gland

Androgen is regulated by ______ in testes

Androgen is regulated by ______ in ovaries

LH

FSH

CAH is when there is too much ______ that cannot be converted to _____ or _____

aldosterone, cortisol, androgen

High aldosterone cause retention of sodium and water