Biomedical Sciences Flashcards
6 cards from real COMLEX-USA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Biomedical Sciences flashcards as text
Which type of collagen is most abundant in articular cartilage?
Answer: Type II collagen
Type II collagen is the predominant collagen in hyaline cartilage, providing tensile strength and resisting compression.
Nitric oxide (NO) produces vasodilation primarily by activating which intracellular enzyme?
Answer: Soluble guanylyl cyclase
NO activates soluble guanylyl cyclase, increasing cGMP, which activates protein kinase G to cause smooth muscle relaxation and vasodilation.
A child has recurrent pyogenic infections with bacteria and fungi. Flow cytometry shows absent CD18. Which condition is this?
Answer: Leukocyte adhesion deficiency (LAD)
LAD type I results from CD18 (beta-2 integrin) deficiency, preventing neutrophils from migrating to infection sites.
The sodium-potassium ATPase pump maintains the resting membrane potential by moving:
Answer: 3 Na+ out and 2 K+ in per cycle
The Na+/K+ ATPase pumps 3 Na+ out and 2 K+ in per ATP hydrolyzed, making it electrogenic and contributing to the negative resting membrane potential.
Which immunoglobulin class is the first to be produced in a primary immune response?
Answer: IgM
IgM is the first antibody class produced during a primary immune response due to its pentameric structure enabling early complement activation.
Okazaki fragments are synthesized on which strand during DNA replication?
Answer: Lagging strand
Okazaki fragments are short DNA segments synthesized discontinuously on the lagging strand, which runs antiparallel to the direction of replication fork movement.