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acrosome |
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acrosome /ac·ro·some/ (ak´ro-sōm) the caplike, membrane-bound structure covering the anterior portion of the head of a spermatozoon; it contains enzymes for penetrating the oocyte.
acrosome [ak′rəsōm′] Etymology: Gk, akron + soma, body the caplike structure surrounding the anterior end of the head of a spermatozoon. It is derived from the Golgi apparatus within the cytoplasm and contains degradative enzymes that function in the penetration of the ovum during fertilization. Also called acrosomal cap, acrosomal head cap. See also acrosomal reaction. acrosomal, adj. acrosome the caplike, membrane-bounded structure that covers the anterior portion of the head of the mammalian spermatozoon; it is bounded by an inner and an outer membrane and contains enzymes involved in penetration of the ovum. acrosome reaction fusion of the outer acrosomal membrane with the sperm plasma membrane, and the breakdown of the fused complex, after the attachment of the spermatozoon to the zona pellucida. It is induced by substances from the egg investments and releases enzymes involved in penetration of the ovum. acrosome Reproduction biology A membrane-bound cap-like structure at the head of a spermatozoon that contains lytic enzymes–acrosin hyaluronidase which degrade the outer coat of the egg and allow the penetration of one sperm. Cf
Acrosome reaction. Cf Capacitation. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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| ? Mentioned in | ? References in periodicals archive | |
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For instance, frog sperm have an acrosome, a
structure that releases enzymes that penetrate the outer membrane of
eggs during fertilization.
Terms explained include: cervical mucus, acrosome, testosterone,
estrogen, progesterone, erection, ejaculation, nocturnal emissions,
homosexuality, masturbation, rape, and sexual molestation. The human acrosome reaction
is highly sensitive to inhibition by cyclodiene insecticides. |
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