01:119:101 Lecture Notes - Lecture 8: Blastocoel, Phospholipid, Blastomere
Document Summary
Studying development: all changed that occur during entire life cycle of individual. Fertilization involves sperm that is flagellated, motile gamete; fuse. Jelly coat thick and comprised of glycoprotein c: external fertilizers sperm and egg are released externally in environment, specifically water. Jelly coat of eggs exudes chemicals into water which attracts sperm. = chemotaxis: sperm contacts jelly coat acrosome reaction, acrosome vesicle on head of sperm which released hydrolytic enzymes. Enzymes partially digest jelly coat: acrosomal process forms sperm structure made of actin filaments; this process protrudes from sperm head and penetrate through coat. Protein molecules at tip bind to receptors on egg, plasma membrane, lock-and-key": recognition between sperm and egg fusion of their plasma membranes. Sperm nucleus enters egg, plasmogomy, one nucleus enters: fast block to polyspermy. Triggers release of ca 2+ from er into cytoplasm: cortical granules. Vesicles which lie in cortex, rim of cytoplasm beneath i. egg, plasma membrane ii.