Organelles Flashcards
Centriole
A cylindrical intracellular organelle composed of nine tubes of microtubules, three in each group (9+0 array); functions in mitosis or meiosis by organizing the microtubules of the spindle apparatus
Chromatid
One complete copy of a DNA strand and its associated nucleoproteins
Chromatin
A histological term referring to the grainy material visible in cell nuclei during interphase; the the appearance of the DNA content of the nucleus when the chromosomes are uncoiled
Chromosomes
Dense structures, composed of tightly coiled DNA strands and associated histones, that become visible visible in the nucleus when a cell prepares to undergo mitosis or meiosis; normal human somatic cells each contain 46 chromosomes
Cilium/cilia
Slender organelles that extend above the free surface of an epithelial cell. Multiple motile cilia generally undergo cycles of movement and are composed of a basal body and microtubules in a 9+2 array; a nonmotile, primary cilium acts as an environmental sensor, and has microtubules arranged in a 9+0 array
Cisterna
An expanded or flattened chamber derived from and associated with the ER
Cytoplasm
The material between the plasma membrane and the nuclear membrane; cell content
Cytoskeleton
A network of microtubules and microfilaments in the cytoplasm
Cytosol
Fluid portion of the cytoplasm
DNA molecule
Two DNA strands wound in a double helix and held together by hydrogen bonds between complementary nitrogenous base pairs
Endoplasmic reticulum
A network of membranous channels in the cytoplasm of a cell that function in intracellular transport, synthesis, storage, packaging, and secretion
Gene
A portion of a DNA strand that functions as a hereditary unit, is located at a particular site on a specific chromosome, and codes for a specific protein or polypeptide
Golgi apparatus
A cellular organelle consisting of a series of membranous plates that give rise to lysosomes and secretory vesicles
Histones
Proteins associated with the DNA of the nucleus; the DNA strands are wound around them
Lysosomes
An intracellular vesicle containing digestive enzymes
Messenger RNA (mRNA)
RNA formed at transcription to direct protein synthesis in the cytoplasm
Microfilaments
Fine protein filaments visible with the electron microscope; components of the cytoskeleton
Microtubules
Microscopic tubules that are part of the cytoskeleton and are a component in cilia, flagella, the centrioles, and spindle fibers
Microvilli
Small, fingerlike extensions of the exposed plasma membrane of an epithelial cell
Mitochondrion
An intracellular organelle responsible for generating most of the ATP required for cellular operations
Nucleolus
The dense region in the nucleus that is the site of RNA synthesis
Nucleoplasm
Fluid content of the nucleus
Nucleoproteins
Proteins of the nucleus that are generally associated with DNA
Nucleus
A cellular organelle that contains DNA, RNA, and proteins; in the CNS, a mass of gray matter
