Cell Biology & Microbiology Flashcards
actin filament
a chain of globular actin molecules that is a major component of the cytoskeleton of eukaryotic cells; abundant in muscle cells
ATP (adenosine tri-phosphate)
a high energy phosphate molecule that provides energy for cellular function
Calvin Cycle
a series of biochemical, enzyme-mediated, light-dependent reactions that take place in the stroma of chloroplasts of photosynthetic organisms, in which carbon dioxide is reduced into organic molecules; also known as Calvin-Benson Cycle or Carbon Fixation
cytochrome
protein found in mitochondrial membranes that functions in oxidative phosphorylation of ADP to form ATP
cytoplasm
the contents outside the nucleus of a membrane-bound cell
cytoskeleton
a cellular organelle within the cytoplasm that functions to maintain cell shape, enable cell motion, and assist in intra-cellular transport and cellular division
diffusion
random continuous movement of particles resulting in an eventually equally
electron transport chain
mitochondrial enzymes that transfer electrons from one complex (I, II, III, and IV) to another, resulting in ATP formation; also known as the respiratory chain
endocytosis
process of material uptake into a cell without passing through the cell membrane
endoplasmic reticulum (ER)
network of membranes within a cell’s cytoplasm that is involved in the synthesis, modification, and transport of cellular materials
exocytosis
a process of cellular secretion through vesicle transport to the cell surface, where the vesicle fuses with the plasma membrane
facilitated diffusion
a passive process of transporting ions or molecules by a specific carrier protein in a membrane
gap junctions
protein channel intercellular network that facilitates passage of ions, hormones, and neurotransmitters from cell to cell
glycolysis
the initial metabolic pathway, completely anaerobic, of carbohydrate catabolism; the most universal process (but not the most efficient) by which all types of cells derive energy from sugars
Golgi apparatus
stack of membranous vesicles that functions in secretion formation within a cell; present in most living cells
hydroplasm
the liquid contents of the gastro-vascular tube
internal membrane
membrane that surrounds organelles; present only in eukaryotic cells
interphase
the non-divisional stage of the cell cycle, during which the DNA is replicated in the nucleus
Krebs cycle
a series of chemical reactions in aerobic respiration occurring naturally in animals; also known as the citric acid cycle
lysosome
a membrane-bound organelle in a cell’s cytoplasm that functions in intracellular digestions
microtubule
long, stiff, hollow cylindrical structure that is a major component of the cytoskeleton and functions to regulate eukaryotic cell’s shape and to control movement
mitochondria
a specialized structure located within cells that metabolize particles into energy sources
nuclear envelope
the membrane system surrounding the nucleus of eukaryotic cells; the system consists of inner and outer membranes that are separated by perinuclear space and perforated by nuclear pores
nucleus
the cell part containing DNA and RNA; responsible for growth and reproduction; the positively-charged, dense center of an atom
organelle
differentiated structure (e.g., mitochondrion, vacuole, or chloroplast) within a cell that performs a specific function
oxidative phosphorylation
the formation of ATP from ADP, taking place in the electron transport chain of the mitochondrion
passive transport
substance transport across a cell membrane by diffusion that does not require energy expenditure
permease
a cell-membrane transport protein or carrier molecule that functions as a transport channel across cellular membranes
peroxisome
eukaryotic organelle that has a single membrane separating it from a cell’s internal fluid (cytosol)
phagocytosis
the process in which a cell engulfs and digests or destroys particulate material
phosphorylation
the process of adding phosphate groups to a compound
plasma membrane
the boundary membrane of a cell, which serves as a selective barrier to regulate the cell’s chemical composition
pore
a minute opening in tissue that serves as an outlet for perspiration (animals) or as a means of absorption and transpiration (plants)
protoplasm
a cell’s living substance, including the cytoplasm and nucleus
protozoan
an animal-like, single-celled eukaryotic organism of economic and scientific importance; many are parasitic, commensal, and/or free-living; responsible for a number of diseases
respiration
the metabolic process that takes place in cells and tissues with the release of energy, the production of carbon dioxide, and the absorption of blood for transport to the lungs
ribosome
a complex cell organelle constructed in the nucleolus, functioning as the site of protein synthesis in the cytoplasm that is composed of proteins plus rRNA and that catalyzes translation of messenger RNA into an amino acid sequence Ribosomes are made up of two non-identical subunits each consisting of a different rRNA and a different set of proteins
rough endoplasmic reticulum (RER)
a membranous tube and sac system of the endoplasmic reticulum that functions in the manufacture of membrane-bound proteins
selectively permeable
a membrane that permits certain materials to cross
smooth endoplasmic reticulum
a membranous tubes system of the endoplasmic reticulum that functions in lipid synthesis
vesicle
a small bladder-like cell that contains fluid
