Download BIOL 303 - Lecture 3 Continuation | BIOL - Developmental Biology and more Quizzes Developmental biology in PDF only on Docsity!
What is the term for the movement of a cell
down a chemical gradient?
Chemotaxis TERM 2
T/F: Chemoattractants are highly specific
species.
DEFINITION 2 T TERM 3
How do chemoattractants activate
sperm?
DEFINITION 3 Cause the sperm mitochondria to produce more ATP (for motion) TERM 4
Describe the acrosome reaction in marine
invertebrates.
DEFINITION 4 Acrosome membrane + sperm cell membranes fuse, acrosomal process is extended TERM 5
What initiates the acrosomal reaction?
DEFINITION 5 Sperm membranes have receptors for specific sulfated polysaccharides on the egg jelly coats --> the binding of these to receptors initiates the acrosomal reaction
What is another species specific interaction?
(think vitelline envelope)
When the acrosomal protein (bindin) binds to an exposed vitelline envelope TERM 7
Bindin receptors are said to be aggregated
into complexes in the vitelline membrane.
Why?
DEFINITION 7 To limit the number of sperm that can bind to the vitelline membrane TERM 8
What is the name of the bindin
receptor?
DEFINITION 8 EBR1 glycoprotein TERM 9
When the sperm + egg membranes fuse,
what happens? What is it rich in?
DEFINITION 9 Formation of the fertilization coneRich in filamentous actin TERM 10
What is the term used to describe the
entrance of more than one sperm?
DEFINITION 10 Polyspermy
What does cortical granule serine protease
do?
Cleaves protein posts that connects the vitelline envelope to the egg membrane TERM 17
What else is released from cortical granules?
What do they do?
DEFINITION 17 Glycosaminoglycans Bind to vitelline envelope, abosorb water and push the envelop away from the egg membrane --> making it a fertilization envelope. TERM 18
List 4 things that the cortical granules
contain.
DEFINITION 18 Cortical granule serine protease Glycosaminoglycans Protein cross-linking enzymes Hyalin TERM 19
What does hyalin
do?
DEFINITION 19 Forms a coat around the egg for structural support TERM 20
Cortical granules are ______ vesicles whose
function is regulated by ___ ions.
DEFINITION 20 -secretory-Ca 2+
All cells have a certain amount of on going
exocytosis (constitutive secretory pathway).
What is special about specialized cells?
-they can use an additional secretory pathway for controlled release of things like hormones, neurotransmitters, digestive enzymes etc. TERM 22
How does the cortical granule reaction occur?
DEFINITION 22 At fertilization, [Ca2+] increases in egg cytoplasm --> triggers cortical granule membrane fusion TERM 23
Where does the calcium come from?
(remember physiology)
DEFINITION 23 Endoplasmic reticulum TERM 24
What opens calcium channels?
DEFINITION 24 IP TERM 25 DEFINITION 25 KNOW
What two physiological events influence
sperm movement before it is in the oviduct?
-uterine contractions are required to get the sperm to the ampulla region-the isthmus slows down sperm and release them slowly to the ampulla TERM 32
How do the sperm navigate once in the
oviduct
DEFINITION 32 Direction cues form the oviduct (temperature gradients) Chemical cues from the oocyte/cumulus cells TERM 33
What is meant by the term capacitation?
DEFINITION 33 The enabling of sperm to fertilize the egg during the voyage through the oviduct TERM 34
What happens during capacitation?
DEFINITION 34 Albumin in female reproductive tract removes cholesterol from sperm membrane --> changes location of lipid rafts that house receptors --> allows for right binding to zona pellucida Proteins + carbs lost (unmasking of binding sites) Membrane potential becomes more negative --> facilitation of membrane fusion (?) Protein phosphorylation --> chaperone protein phosphorylated --
important for Z.P. receptor Acrosomal membrane comes into contact w. sperm membrane (acrosome reaction) TERM 35
Depending on the condition, what is the effect
of cholesterol? High cholesterol = ____?
DEFINITION 35 -It can either increase/decrease membrane fluidity-low membrane fluidity
What is the zona pellucida?
Like the vitelline envelope, but much thicker TERM 37
Zona Pellucida has a glycoprotein matrix that
consists of three MAIN proteins:
DEFINITION 37 Zona 1 Zona 2 Zona 3 TERM 38
What is the main protein that sperm
membrane binds to? What does it initiate?
DEFINITION 38 ZP3Acrosome reaction TERM 39
What happens in the mammalian slow block?
DEFINITION 39 The Z.P. is modified such that it can no longer bind sperm --> targets ZP TERM 40
In order for there to be a fusion of genetic
material - what must first happen?
DEFINITION 40 Sperm must decondensed as its tightly packaged with protamines
