Lipid Metabolism — Flashcards

Flashcard 81: _____ is released from the phospholipid cell membrane by the enzyme phospholipase A2

Answer: Arachidonic acid

Flashcard 82: _____ is an altered form of low-density lipoprotein (LDL) that contains the apo B-100 portion of LDL linked to apo a

Answer: Lipoprotein a [Lp(a)]

Flashcard 83: Gallstone chemistry most commonly seen is _____ cholesterol monohydrate

Answer: crystalline

Flashcard 84: The serum lipoproteins elevated in type III familial dyslipidemia (dysbetalipoproteinemia) are _____ and IDL (VLDL remnants).

Answer: chylomicron remnants

Flashcard 85: The enzyme lipoprotein lipase is activated by _____ and apoprotein C-II

Answer: insulin

Extra: Lipoprotein lipase (LPL) is an enzyme located on the vascular endothelial surface that hydrolyzes triglycerides in chylomicrons and VLDL. Key regulatory points: 1. **Apoprotein C-II**: A mandatory cofactor for LPL activation. 2. **Insulin**: Stimulates LPL synthesis and secretion in adipose tissue (promoting fat storage in the well-fed state). 3. **Tissue Specificity**: In contrast to adipose tissue, LPL in cardiac and skeletal muscle has a lower Km (higher affinity) and is not stimulated by insulin, allowing muscle to prioritize lipid uptake even when glucose is low.

Flashcard 86: Apo B-_____ is found only on particles originating from the intestines, whereas Apo B-100 is found only on particles originating from the liver

Answer: 48

Flashcard 87: _____ causes atherosclerosis whereas apolipoprotein-A prevents atherosclerosis

Answer: apolipoprotein-a

Flashcard 88: In the liver, bile acids are conjugated to the amino acids _____ or taurine to form bile salts

Answer: glycine

Flashcard 89: Acetyl-CoA is converted to _____ via the enzyme acetyl-CoA carboxylase (fatty acid synthesis)

Answer: malonyl-CoA

Flashcard 90: _____-carbon steroids, such as DHEA and androstenedione, have androgenic activity and are precursors to estrogen

Answer: 19