cellular component
component of a cell
Schmidt-Lanterman incisure
Regions within compact myelin in which the cytoplasmic faces of the enveloping myelin sheath are not tightly juxtaposed, and include cytoplasm from the cell responsible for making the myelin. Schmidt-Lanterman incisures occur in the compact myelin in
stress fiber
aspect of cell structure
lamellar granule
secretory organelle
climbing fiber
axons of inferior olive neuron
cell envelope
envelope that surrounds a bacterial cell and includes the cytoplasmic membrane and everything external, encompassing the periplasmic space, cell wall, and outer membrane if present
parallel fiber
fiber that results from the bifurcation of a cerebellar granule cell axon in the molecular layer into two diametrically opposed branches, that are oriented parallel to the long axis of the folium
Schaffer axon collateral
part of axon of a CA3 pyramidal neuron that projects to hippocampal area CA1
terminal web
actin-rich cytoskeletal network located beneath the microvilli of the apical plasma membrane of polarized epithelial cells. In addition to actin filaments, the terminal web may contain actin-binding proteins, myosin motor proteins, and intermediat
Transcription factories
sites in the cell nucleus where DNA transcription occurs
secondary cell wall
plant cell wall that is no longer able to expand and so does not permit growth. Secondary cell walls contain less pectin than that of primary cell walls. The secondary cell is mostly composed of cellulose and is strengthened with lignin
septum
cell wall that forms between two daughter cells as a result of cell division
extracellular region
space external to the outermost structure of a cell
dystrophin-associated glycoprotein complex
multiprotein complex that forms a strong mechanical link between the cytoskeleton and extracellular matrix
nuclear cap binding complex
conserved heterodimeric protein complex
H zone
relatively pale zone traversing the center of the A band of a sarcomere, visible in relaxed muscle fibers; consists of the central portion of thick (myosin) filaments that are not overlapped by thin (actin) filaments
organelle inner membrane
the inner, i.e. lumen-facing, lipid bilayer of an organelle envelope; usually highly selective to most ions and metabolites
mitochondrial respiratory chain complex I
protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain
Slit-Robo signaling complex
protein-carbohydrate complex that consists of a transmembrane roundabout (Robo) receptor, an extracellular Slit ligand and heparin/heparan sulfate
type I site-specific deoxyribonuclease complex
multisubunit complex that recognizes specific short DNA sequences
urease complex
multiprotein nickel-containing complex that catalyses the hydrolysis of urea to ammonia and carbon dioxide
type II site-specific deoxyribonuclease complex
protein complex that functions as an endonuclease to cleave DNA at or near a specific recognition site, when that site is unmethylated
cellular bud neck contractile ring
contractile ring, i.e. a cytoskeletal structure composed of actin filaments and myosin, that forms beneath the plasma membrane at the mother-bud neck in mitotic cells that divide by budding in preparation for completing cytokinesis. An example of t
ribosome
intracellular organelle, site of protein biosynthesis resulting from translation of messenger RNA (mRNA), consisting of two subunits
adherens junction
cell junction at which anchoring proteins extend through the membrane and attach to actin filaments
plasmid
small DNA molecule within a cell that is physically separated from a chromosomal DNA and can replicate independently
signal recognition particle
protein-RNA complex facilitating translocation of proteins across membranes
growth cone
migrating motile tip of a growing nerve cell axon or dendrite
lipid droplet
intracellular non-membrane-bounded organelle with a matrix of coalesced lipids surrounded by a phospholipid monolayer
sarcoplasm
The cytoplasm of a muscle cell; includes the sarcoplasmic reticulum.
leucoplast
part of a plant
cytostome
Stable, specialized structure for the ingestion of food by the cell into phagosomes.
bivalent
pair of homologous chromosomes during meiotic synapsis
spindle
array of microtubules and associated molecules that forms between opposite poles of a eukaryotic cell during mitosis or meiosis and serves to move the duplicated chromosomes apart
tight junctions
type of cellular connection that minimizes metabolic flows between adjacent cells
inclusion body
cell component formed of aggregated molecules such as proteins or other biopolymers
chiasma
connection formed between chromatids, visible during meiosis, thought to be the point of the interchange involved in crossing-over
Lamina densa
layer of the skin
photosystem I
class of protein complexes, the second protein complex in photosynthetic light reactions
excitatory synapse
synapse in which an action potential in the presynaptic cell increases the probability of an action potential occurring in the postsynaptic cell
P-body
focus in the cell cytoplasm where mRNAs may become inactivated by decapping or some other mechanism
telomere
terminal region of a linear chromosome that including the telomeric DNA repeats and associated proteins
micropyle
external encapsulating structure part of the chorion. A single cone-shaped specialization that forms an opening in the chorion that allows sperm entry into the egg prior to fertilization
cortical granule
secretory vesicle that is stored under the cell membrane of an egg. These vesicles fuse with the egg plasma membrane as part of egg activation and are part of the block to polyspermy
chromatoid body
ribonucleoprotein complex found in the cytoplasm of male germ cells
ciliary basal body
membrane-tethered, short cylindrical array of microtubules and associated proteins found at the base of a eukaryotic cilium (also called flagellum) that is similar in structure to a centriole and derives from it. The cilium basal body is the site o
extracellular vesicle
vesicle that is part of the extracellular region
complement component C1 complex
protein complex
G-protein beta/gamma-subunit complex
G beta Gamma complex
FACT complex
abundant nuclear complex, which was originally identified in mammalian systems as a factor required for transcription elongation on chromatin templates. The FACT complex has been shown to destablilize the interaction between the H2A/H2B dimer and