Fertilization Flashcards
(27 cards)
job of binding to zona pellucida
protects oocyte
what reaction happens to the sperm
acrosomal reaction
sperm is engulfed by
oocyte
what are the three glycoproteins of the zona pellucida
ZP1
ZP2
ZP3
structural glycoproteins of zona pellucida
ZP1 and ZP2
binding protein of zona pellucida
ZP3
job of hyperactivity
traversing the cumulus cells
what are the cumulus cells embedded in
extracellular matric that is made up of hyaluronic acid
capacitated sperm contain
active membrane proteins=functional enzymes=hyaluronidase
1st step to fertilization
hyperactivity
2nd step to fertilization
binding to the zona pellucida
what is the first binding site of ZP
zona binding region
where is the seconding binding site of ZP
acrosome reaction promoting region
which glycoprotein is a receptor for sperm
ZP3
what enzyme does the acrosome contain
acrosin
acrosin
digests zona pellucida
what is the basis of the acrosome reaction
contents of acrosome leak out
- membrane fusion occurs between plasma membrane and outer acrosomal membrane
what occurs due to the acrosome reaction
- fusing of the two membranes (plasma membrane and outer acrosomal membrane)
- acrosome contents released
- exposure of fusion proteins on equatorial segment
what are the blocks to polyspermy
- zona block
- vitelline block
what occurs during the zona block
ZP modifies/hardens due to contents of cortical granules released from cortical reaction
what occurs during vitelline block
oocyte PM changes after fusion so it is unresponsive to subsequent sperm
what won’t the sperm be able to recognize after vitelline block
fusion proteins
what causes the DNA in sperm to be so condensed
protamine’s inside of histones
how do protamine’s cause the DNA to be so condensed
disulfide bridges (S=S)
