Metabolism — Flashcards

Flashcard 1151: Phosphorylation of glycogen synthase causes enzyme _____ (activation/inactivation)

Answer: inactivation

Flashcard 1152: Which two organs does galactose primarily enter?

Answer: Liver and kidneys

Extra: Galactose metabolism primarily occurs in the liver, with a secondary contribution from the kidneys. Both organs express the GLUT2 transporter, allowing for insulin-independent uptake of galactose. While galactose is used in the brain for the synthesis of galactolipids (like cerebrosides), the bulk of dietary galactose is cleared by the liver and kidneys.

Flashcard 1153: Which is a better intracellular buffer in physiologic pH range, oxy- or deoxyhemoglobin?_____

Answer: Deoxyhemoglobin

Flashcard 1154: Which steroid hormone enzyme deficiency (21- or 11-hydroxylase) presents with decreased renin activity?_____

Answer: 11-hydroxylase

Flashcard 1155: Which growth factors/cytokines utilize **receptor tyrosine kinase** (intrinsic) signaling?

Answer: Insulin, IGF-1, FGF, PDGF, EGF, and **TGF-α**

Extra: In contrast, **TGF-β** utilizes a receptor **serine/threonine kinase** pathway (SMAD signaling). Most other cytokines (e.g., ILs, IFNs, EPO, G-CSF) utilize the **JAK/STAT** pathway (non-receptor tyrosine kinase).

Flashcard 1156: What acute phase reactant is downregulated during inflammation by being internalized into macrophages to sequester iron?_____

Answer: Transferrin

Flashcard 1157: Disorders of fibrinolysis typically present with increased _____ split products

Answer: fibrinogen

Flashcard 1158: Thyrotropin receptor antibodies (TRAb) are components of the Ig_____ fraction of plasma protein

Answer: G

Flashcard 1159: What vitamin deficiency may be caused by malignant carcinoid syndrome? _____

Answer: Niacin (B3) deficiency

Flashcard 1160: _____ is a mineral that is essential for the activity of 100+ enzymes

Answer: Zinc