muscle protein filament in a sarcomere; its movement shortens the sarcomere, yielding muscle contraction. Actin filaments play a role in the movement of the cell and its organelles
programmed cell death involving a cascade of specific cellular events leading to death and destruction of the cell
aerobic rod-shaped spore-producing bacterium
A eukaryotic cell organelle consisting of a 9 + 0 arrangement of microtubule triplets; may organize the microtubule assembly of a cilium or flagellum; structurally identical to a centriole.
A sticky layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces.
the smallest unit that can perform all life processes; cells are covered by a membrane and contain DNA and cytoplasm
in a prokaryotic cell, the portion composed of the plasma membrane, the cell wall and the gycocalyx
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
strong wall outside a plant cell's plasma membrane that protects the cell and maintains its shape
A membrane-enclosed sac occupying most of the interior of a mature plant cell, having diverse roles in reproduction, growth, and development.
A structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 + 0 pattern. An animal cell usually has a pair of centrioles involved in cell division.
region of cytoplasmic material that in animal cells contains structures called centrioles
organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy (photosynthesis)
The complex of DNA and proteins that makes up a eukaryotic chromosome. When the cell is not dividing, it exists as a mass of very long, thin fibers that are not visible with a light microscope.
type of plastid that synthesizes and stores red, yellow, and orange pigments, responsible for colors of many fruits and flowers
A threadlike linear strand of DNA and associated proteins in the nucleus of eukaryotic cells that carries the genes and functions in the transmission of hereditary information
A short cellular appendage specialized for locomotion, formed from a core of nine outer doublet microtubules and two inner single microtubules ensheathed in an extension of plasma membrane.
any spherical or nearly spherical bacteria
Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.
Photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae).
the region of a cell located inside the cell membrane (in prokaryotes) or between the cell membrane and nucleus (in eukaryotes); contains a gel-like material and cell organelles
a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence
The collection of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles; includes the smooth and rough endoplasmic reticulum, the Golgi apparatus, lysosomes, and vacuoles.
a network of tubular membranes within the cytoplasm of the cell, occurring either with a smooth surface (smooth endoplasmic reticulum) or studded with ribosomes (rough endoplasmic reticulum), involved in the transport of materials.
A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Examples of organisms with these cells are protists, plants, fungi, and animals; organisms are in the Eukarya domain
fingerlike projections that create wavelike currents(peristalsis) in fluid surrounding the ovary to move the ovum into the uterine tube; Filamentous proteins on the surface of bacterial cells
a lash-like appendage used for locomotion (e.g., in sperm cells and some bacteria and protozoa)
A layer of exopolysaccharide fibers on the surface of bacterial cells which may be involved in adherence to a surface. Sometimes a general term for a bacterial capsules; if compact called capsule and if diffuse, called slime layer
stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum
A stacked portion of the thylakoid membrane in the chloroplast; functions in the light reactions of photosynthesis.
in a bacterium, stored nutrients for later use
rope-like assemblies of fibrous polypeptides in the cytoskeleton that provide support and strength to cells; A component of the cytoskeleton that includes all filaments intermediate in size between microtubules and microfilaments.
Colorless plastids that synthesize and store starches and oils
membrane-bound sac containing digestive enzymes that can break down proteins, nucleic acids, and polysaccharides
unstructured semifluid substance that fills the space between cells in connective tissues or inside organelles, the surface area exposed to fluids, such as where the production of energy takes place, in a mitochondrion
plasma membrane that folds into the cytoplasm and increases surface area
A hollow rod of tubulin protein in the cytoplasm of all eukaryotic cells and in cilia, flagella, and the cytoskeleton.
in eukaryotic cells, the cell organelle that is surrounded by two membranes and that is the site of cellular respiration, which produces ATP
protein that moves along either actin filaments or microtubules and translocates organelles
double membrane perforated with pores that control the flow of materials in and out of the nucleus
opening in the nuclear envelope that permits the passage of proteins into the nucleus and ribosomal subunits out of the nucleus
Region in prokaryotic cell where DNA is concentrated, not enclosed by membrane
The organelle where ribosomes are made, synthesized and partially assembled, located in the nucleus
semifluid medium of the nucleus containing chromatin
organelle that controls all the activities of a cell and contains hereditary material made of DNA
one of the small bodies that are found in the cytoplasm of a cell and that are specialized to perform a specific function
enzyme-filled vesicle in which fatty acids and amino acids are metabolized to hydrogen peroxide that is broken down to harmless products
thin outer boundary of a cell composed of a bilayer of phospholipids in which proteins are embedded that regulates the traffic of chemicals between the cell and its surroundings
a circular DNA molecule that is usually found in bacteria and that can replicate independent of the main chromosome
group of closely related plant organelles that are used for storage of starches, lipids, or pigments; includes chloroplasts, chromoplasts, and amyloplasts (leucoplasts).
string of ribosomes simultaneously translating regions of the same mRNA strand during protein synthesis
A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
A temporary, foot-like extension of a cell, used for locomotion or engulfing food
small particle in the cell on which proteins are assembled; made of RNA and protein
rough endoplasmic reticulum
System of internal membranes within the cytoplasm. Membranes have the presence of ribosomes; functions in transport of substances such as proteins within the cytoplasm
a functionally specialized substance (especially one that is not a waste) released from a gland or cell by exocytosis
elongated, hollow appendages that pull 2 cells together prior to DNA transfer from one cell to the other found in bacterium
smooth endoplasmic reticulum
A network of membranes inside eukarytoic cells invovled in lipid synthesis (steroid in gonads), detoxification (in liver cells), and/or Ca2+ storage (muscle cells); lacks ribosomes on the surface
A type of bacterial cell with a rigid spiral shape and external flagella.
A coiled, spiral-shaped bacterium that has endoflagella and flexes as it moves.
an area within a chloroplast that lies between the thylakoid membranes; serves as the site of the Calvin cycle in photosynthesis which involves the synthesis of carbohydrates
surface-area-to volume ratio
ratio of a cell's outside area to its internal volume
a flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy; where the light reactions of photosynthesis occurs
membrane-bound sac that buds from the endoplasmic reticulum or the Golgi apparatus, storage structures for food, water, minerals, waste
small membrane-bound sac that functions in moving products into, out of, and within a cell