Biochemical Pathways And Genes Flashcards
What is spermatogenesis?
The process by which spermatogonia develop into mature spermatozoa, involving mitotic divisions, meiosis, and spermiogenesis.
What occurs during mitosis in spermatogenesis?
Spermatogonia undergo mitotic divisions to produce primary spermatocytes.
What happens during meiosis in spermatogenesis?
Primary spermatocytes undergo two rounds of meiotic division to produce haploid spermatids.
What is spermiogenesis?
Spermatids undergo structural and biochemical changes, including the formation of acrosome, flagellum, and elimination of excess cytoplasm, to form mature spermatozoa.
How is testosterone synthesized?
Testosterone synthesis occurs through a series of enzymatic reactions in Leydig cells, primarily involving the conversion of cholesterol to testosterone.
How is cholesterol transported into Leydig cells?
Cholesterol is transported into Leydig cells via steroidogenic acute regulatory protein (StAR).
What is steroidogenesis?
Cholesterol is converted to pregnenolone by the enzyme cytochrome P450 side-chain cleavage enzyme (CYP11A1).
What enzymes are involved in the conversion of pregnenolone to testosterone?
Pregnenolone is further converted to testosterone through a series of enzymatic reactions involving 17a-hydroxylasel17,20-lyase (CYP17A1) and 3β-hydroxysteroid dehydrogenase (HSD3B).
What is the role of the androgen receptor (AR)?
The androgen receptor, encoded by the AR gene, mediates the biological effects of testosterone by binding to androgen response elements (ARES) in target genes.
What does the androgen receptor regulate?
The androgen receptor regulates gene expression involved in male sexual development and function.
