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36 Cards in this Set
- Front
- Back
Cholesterol is the precursor to several major steroid hormones. Name 5.
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Progestagens, Glucocorticoids, Mineralocorticioids, Androgens, and Estrogens.
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Cholesterol reacts to form pregnenolone. What is the enzyme?
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Mitochondrial Monooxygenase (aka P450 Mixed function oxidase). Cleaves off C22-27. Increased activity with ACTH. AKA side chain cleavage enzyme.
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Pregnenolone produces ___ which is the precursor to the steroid hormones.
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Progesterone.
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The adrenal cortex produces ___ and ___ final products from the progesterone pathway.
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Cortisol and Aldosterone.
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The gonads produce ___, ___, and ___.
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Estrone, Testosterone, and Estradiol.
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Let's Play: HOW MANY CARBONS ARE IN THAT STEROID!!
Cholesterol |
C27
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Progestagens
Corticoids Androgens Estrogens |
Progestagens, C21
Corticoids, C21 Androgens, C19 Estrogens, C18 **Be able to recognize structures, according to Siefert |
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What is the major site of catabolism of steroid hormones?
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Liver
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What are GAGs?
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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.
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What is a proteoglycan?
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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.
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What are the jobs of GAGs and proteoglycans?
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Ground substance of ECM. Forms extacellular fluid such as bone, cartilage, vitreous fluid, synovial fluid, and mucus.
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They are highly Negative/Positive and Hydrated/Hydrophobic. Act as a gel like matrix and expand and contract. Effective ___.
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They are highly Negative and Hydrated. Act as a gel like matrix and expand and contract. Effective lubricant.
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Do GAGs have branched chains? What are the carbons that link (numbers)?
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NO branches. Linkages are 1,3, or 4 and alpha/beta. NO 6!!
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The two major components of the disac are an acidic sugar and an aminosugar (usually acetylated). Name the sugars.
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Acidic- GlcUA, IdUA, Galactose (with sulfur)
Aminosugar- GlcNAc, GalNAc |
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What is hyaluronic acid made of?
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GlcUA B1,3 GlcNAc
NOT sulfated, NOT covalently linked to protein |
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With proteoglycans what binds the GAGs? What sugar linkages?
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Covalent binding is to SER/THR-O-Sugar linkages.
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The following four cards are GAGs that compose proteoglycans. I'll name the GAG, you name the main function.
1. Chondroitin Sulfate |
Found in tendons, ligaments, GS, and cartilage.
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2. Keratan Sulfate
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Found in cornea, cartilage
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3. Heparin and Heparan
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Heparin- intracellular in mast cells underlying epithelial cells of arteries
Heparan- Cell surface and important in blood coagulation; anti-coagulation |
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4. Dermatan Sulfate
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Skin, blood, vessels, and heart valve.
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Aggrecan is a component of cartilage. It is a proteogylcan composed mostly of what two things?
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Chondoroitin sulfate and keratan sulfate chains
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The core protein is synthesized in the lumen of the ___ as a ___.
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ER; glycoprotein.
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The leader sequence is added in the lumen of the ___.
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golgi
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What is the order of the leader tri-saccharide?
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Xyl is added first, then two Gals. Order: Core Protein- Ser, Xyl, Gal, Gal.
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After the leader sequence of tri-saccharide what is added? Keep in sequential order.
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1. GlcUA,
2. GalNAc, 3. and GlcUA. PAPS then sulfates the GalNAc (middle). |
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Elongation is addition of the reducing end of a sugar to what end the growing molecule?
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non-reducing end
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Sulfation occurs at the ___ level with PAPs/sulfokinase.
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polymer
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How do sugars such as PAPs and UDP-_GalNAc cross the golgi membrane?
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Antiport system. Sugar nucleotides come in and nucleoside products go out (AMP and UDP).
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Hyaluronic acid synthesis occurs in the ___ membrane.
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Plasma
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Is there a protein core of leader sequence?
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NO
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The chain grows from the reducing end/ or nonreducing end?
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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.
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Multiple ___ attach to the core protein ___.
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Multiple chondroitin sulfate attach to the core protein aggrecan. Bottle-brush structure.
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These proteoglycans (aggrecan with chondroitin sulfate and keratan sulfate) attach to ___.
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Hyaluronic acid.
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Proteoglycans come into the cell for degradation via ___. They are taken to the ___ for degradation.
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Proteoglycans come into the cell for degradation via endocytosis. They are taken to the lysosome for degradation.
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Proteolysis of core protein can occur in extra cellular fluid. What is the key step after this?
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Removal of the SO4 by sulfatase. This is because lysosomal glycosidases cannot hydrolyze sulfated oligosaccs.
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Glycosidases remove the sugars one at a time at which end?
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non-reducing end.
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