Uth Biochemistry Block Iii Lecture 9

Front 1

Cholesterol is the precursor to several major steroid hormones. Name 5.

Back 1

Progestagens, Glucocorticoids, Mineralocorticioids, Androgens, and Estrogens.

Front 2

Cholesterol reacts to form pregnenolone. What is the enzyme?

Back 2

Mitochondrial Monooxygenase (aka P450 Mixed function oxidase). Cleaves off C22-27. Increased activity with ACTH. AKA side chain cleavage enzyme.

Front 3

Pregnenolone produces ___ which is the precursor to the steroid hormones.

Back 3

Progesterone.

Front 4

The adrenal cortex produces ___ and ___ final products from the progesterone pathway.

Back 4

Cortisol and Aldosterone.

Front 5

The gonads produce ___, ___, and ___.

Back 5

Estrone, Testosterone, and Estradiol.

Front 6

Let's Play: HOW MANY CARBONS ARE IN THAT STEROID!!

Cholesterol

Back 6

C27

Front 7

Progestagens

Corticoids

Androgens

Estrogens

Back 7

Progestagens, C21

Corticoids, C21

Androgens, C19

Estrogens, C18

**Be able to recognize structures, according to Siefert

Front 8

What is the major site of catabolism of steroid hormones?

Back 8

Liver

Front 9

What are GAGs?

Back 9

Heteropolysaccharieds. Family of linear polymers composed of repeating dissacharide untis. One is Always N-acetylglucosamine or N-acetylglactosamine. The other is generally a uronic acid.

Front 10

What is a proteoglycan?

Back 10

It is a cell surface macromolecule of the cell surface with one or more GAG covalently bound. The GAGs are more numerous mass of the structure and define the site of biological activity.

Front 11

What are the jobs of GAGs and proteoglycans?

Back 11

Ground substance of ECM. Forms extacellular fluid such as bone, cartilage, vitreous fluid, synovial fluid, and mucus.

Front 12

They are highly Negative/Positive and Hydrated/Hydrophobic. Act as a gel like matrix and expand and contract. Effective ___.

Back 12

They are highly Negative and Hydrated. Act as a gel like matrix and expand and contract. Effective lubricant.

Front 13

Do GAGs have branched chains? What are the carbons that link (numbers)?

Back 13

NO branches. Linkages are 1,3, or 4 and alpha/beta. NO 6!!

Front 14

The two major components of the disac are an acidic sugar and an aminosugar (usually acetylated). Name the sugars.

Back 14

Acidic- GlcUA, IdUA, Galactose (with sulfur)

Aminosugar- GlcNAc, GalNAc

Front 15

What is hyaluronic acid made of?

Back 15

GlcUA B1,3 GlcNAc

NOT sulfated, NOT covalently linked to protein

Front 16

With proteoglycans what binds the GAGs? What sugar linkages?

Back 16

Covalent binding is to SER/THR-O-Sugar linkages.

Front 17

The following four cards are GAGs that compose proteoglycans. I'll name the GAG, you name the main function.

1. Chondroitin Sulfate

Back 17

Found in tendons, ligaments, GS, and cartilage.

Front 18

2. Keratan Sulfate

Back 18

Found in cornea, cartilage

Front 19

3. Heparin and Heparan

Back 19

Heparin- intracellular in mast cells underlying epithelial cells of arteries

Heparan- Cell surface and important in blood coagulation; anti-coagulation

Front 20

4. Dermatan Sulfate

Back 20

Skin, blood, vessels, and heart valve.

Front 21

Aggrecan is a component of cartilage. It is a proteogylcan composed mostly of what two things?

Back 21

Chondoroitin sulfate and keratan sulfate chains

Front 22

The core protein is synthesized in the lumen of the ___ as a ___.

Back 22

ER; glycoprotein.

Front 23

The leader sequence is added in the lumen of the ___.

Back 23

golgi

Front 24

What is the order of the leader tri-saccharide?

Back 24

Xyl is added first, then two Gals. Order: Core Protein- Ser, Xyl, Gal, Gal.

Front 25

After the leader sequence of tri-saccharide what is added? Keep in sequential order.

Back 25

1. GlcUA,
2. GalNAc,
3. and GlcUA.

PAPS then sulfates the GalNAc (middle).

Front 26

Elongation is addition of the reducing end of a sugar to what end the growing molecule?

Back 26

non-reducing end

Front 27

Sulfation occurs at the ___ level with PAPs/sulfokinase.

Back 27

polymer

Front 28

How do sugars such as PAPs and UDP-_GalNAc cross the golgi membrane?

Back 28

Antiport system. Sugar nucleotides come in and nucleoside products go out (AMP and UDP).

Front 29

Hyaluronic acid synthesis occurs in the ___ membrane.

Back 29

Plasma

Front 30

Is there a protein core of leader sequence?

Back 30

NO

Front 31

The chain grows from the reducing end/ or nonreducing end?

Back 31

Reducing end. Opposite of Chondroitin Sulfate Synthesis. Page 120. You add to the reducing end in the cytoplasm while spitting out the non-reducing end into the ECM.

Front 32

Multiple ___ attach to the core protein ___.

Back 32

Multiple chondroitin sulfate attach to the core protein aggrecan. Bottle-brush structure.

Front 33

These proteoglycans (aggrecan with chondroitin sulfate and keratan sulfate) attach to ___.

Back 33

Hyaluronic acid.

Front 34

Proteoglycans come into the cell for degradation via ___. They are taken to the ___ for degradation.

Back 34

Proteoglycans come into the cell for degradation via endocytosis. They are taken to the lysosome for degradation.

Front 35

Proteolysis of core protein can occur in extra cellular fluid. What is the key step after this?

Back 35

Removal of the SO4 by sulfatase. This is because lysosomal glycosidases cannot hydrolyze sulfated oligosaccs.

Front 36

Glycosidases remove the sugars one at a time at which end?

Back 36

non-reducing end.