crc press

997
Spermatids • Sphinganine 1-Phosphate Aldolase
Spermatids Haploid cells resulting from a second
meiotic division in spermatogenesis that differentiate
into mature spermatozoa.
Spermatocyte A cell that undergoes meiosis and
gives rise to sperm.
Spermatogenesis The process of the formation
of the male gamete, including meiosis and transformation
of four spermatides into spermatozoa or
sperm.
Spermatogonia
Plural of spermatogonium.
Spermatogonium Undifferentiated germ cell that
gives rise to primary spermatocytes.
Spermatozoa
Spermatozoan
by meiosis.
Spermatozoon
Spermaturia
Spermicidal
Plural of spermatozoon.
Spermidine (mol wt 145)
formed from putrescine.
Haploid male gamete produced
The motile male gamete.
The presence of semen in the urine.
Any substance that kills sperm.
NH 2 (CH 2 ) 4 NH(CH 2 ) 3 NH 2
A biogenic amine
Spermidine Dehydrogenase The enzyme that
catalyzes the following reaction:
Spermidine + acceptor + H 2 O
1,3-Diamino-propane + 4-aminobutanal +
reduced acceptor
Spermidine Synthetase The enzyme that catalyzes
the following reaction:
Sph
Abbreviation for sphingosine.
SphI A restriction endonuclease from Streptomyces
phaeochromogenes with the following specificity:
Sphaeroplast
Sphaerosome
5′..........GCATGC..........3′
3′..........CGTACG..........5′
See spheroplast.
Variant spelling of spherosome.
Sphaerotilus A genus of Gram-negative, rodshaped,
obligately aerobic, asporogenous bacteria.
S-Phase The synthetic phase in the eukaryotic
cell cycle during which DNA is synthesized.
A ganglio block-
Spherophysine (mol wt 198)
ing agent.
H 3 C
H 3 C
C CHCH 2 N(CH 2 ) 4 NH 2
C
HN NH 2
Spheroplast Gram-negative bacterial cell in
which the cell wall has been partially removed by
an enzymatic or chemical treatment.
Spherosome A lysosomelike, lipid-storage structure
derived from endoplastic reticulum in plants.
Spherulin An antigen derived from the spherules
of Coccidioides immitis used in skin testing for
delayed hypersensitivity.
Sphinganine (mol wt 302) An intermediate in
the biosynthesis of ceramide.
OH
CH(CH 2 ) 14 CH 3
S-Adenosylmethioninamine + putrescine
H 2 N
C
H
5′-Methylthioadenosine + spermidine
Spermine (mol wt 202) A biogenic polyamine
formed from spermidine that occurs in all tissues
of eukaryotes but not in prokaryotes.
NH 2 (CH 2 ) 4 NH (CH 2 ) 4 NH(CH 2 ) 3 NH 2
Spermine Synthetase The enzyme that catalyzes
the following reaction:
S-Adenosylmethioninamine + spermidine
5′-Methylthioadenosine + spermine
CH 2 OH
Sphinganine Kinase The enzyme that catalyzes
the following reaction:
ATP + sphinganine
ADP + sphinganine 1-phosphate
Sphinganine 1-Phosphate Aldolase The enzyme
that catalyzes the following reaction:
Sphinganine 1-phosphate
Phosphoethanolamine + palmitaldehyde