Anatomy of the Cell Flashcards
Tiny spherical bodies composed of RNA and proteins; floating free or attached to a membranous structure (the rough ER) in the cytoplasm. Actual sites of protein synthesis
ribosomes
Membranous system of tubules that extends throughout the cytoplasm; two varieties: rough and smooth. Rough ER is studded with ribosomes; tubules of the rough ER provide an area for storage and transport of the proteins made on the ribosomes to other cell areas. Smoot ER, which has no function in protein synthesis, is a site of steroid and lipid synthesis, lipid metabolism, and drug detoxification
Endoplasmic reticulum (ER)
Stack of flattened sac with bulbous ends and associated small vesicles; found close to the nucleus. Plays a role in packaging proteins or other substances for export from the cell or incorporation into the plasma membrane and in packaging lysosomal enzymes.
Golgi apparatus
Various-sized membranous sacs containing digestive enzymes including acid hydrolases; function to digest worn-out cell organelles and foreign substances that enter the cell. Have the capacity of total cell destruction if ruptured and are for this reason referred to as “suicide sacs”
Lysosomes
Small lysosome-like membranous sacs containing oxidase enzymes that detoxify alcohol, free radicals, and other harmful chemicals. They are particularly abundant in liver and kidney cells.
Peroxisomes
Generally rod-shaped bodies with a double-membrane wall; inner membrane is shaped into folds, or cristae; contain enzymes that oxidize foodstuffs to produce cellular energy (ATP); often referred to as “powerhouses of the cell”
Mitochondria
Paired, cylindrical bodies that lie at right angles to each other, close to the nucleus. Internally each centriole is composed of nine triplets of microtubules. As part of the centrosome, they direct the formation of the mitotic spindle during cell division; form the bases of cilia and flagella and in that role are called basal bodies
Centrioles
Form an internal scaffolding called the cytoskeleton. Provide cellular support; function in intracellular transport. Microfilaments are formed largely of actin, a contractile protein, and thus are important in cell mobility, particularly in muscle cells. Intermediate filaments are stable elements composed of various proteins and resist mechanical forces acting on cells. Microtubules form the internal structure of the centrioles and help determine cell shape.
Cytoskeleton and its’ elements: microfilaments, intermediate filaments, and microtubules
Cell contents between nucleus and plasma membrane
Cytoplasm
Aqueous component of cytoplasm
Cytosol
-Separates cell contents from the surrounding environment
-Provides a protective barrier
-Composed of phospholipids and globular proteins
-Selectively permeable
-Carbohydrate side chains
-Resting potential
Plasma membrane
-Fingerlike projections or folds
-Increase surface area of cell available for absorption or passage of materials
Microvilli
-Genetic material loosely dispersed throughout nucleus (threadlike)
-Not dividing
Chromatin
-Coiled and condensed chromatin
-Dividing
Chromosomes
-Spherical bodies composed of proteins and RNA
-Assembly sites for ribosomes
Nucleoli
