component of cytoskeleton; plays a role in the movement of the cell and its organelles; a protein filament in a sarcomere of a muscle, its movement shortens the sarcomere yielding contraction
A sticky layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces.
smallest unit of life that displays all the properties of life; composed of cytoplasm surrounded by a membrane
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
cellular structure that surrounds a plant, protistan, fungal or bacterial cell and maintains the cells shape and rigidity
in a plant cell a large fluid filled sac that stores metabolites. During growth it enlarges forcing primary cell wall to expand and the cell surface area to volume ratio to increase
in animal cells, a cytoplasmic organelle that organizes the mitotic spindle fibers during cell reproductions
Central microtubule organizing center of cells. In animal cells, it contains two centrioles.
Membrane-bounded organelle in algae and plants with chlorophyll-containing membranous thylakoids; where photosynthesis takes place
threadlike structure within the nucleus containing the genetic information that is passed from one generation of cells to the next... composed of condensed chromatin
Photosynthetic bacterium that contains chlorophyll and releases oxygen; formerly called a blue-green alga
Internal framework of the cell, consisting of microtubules, actin filaments, and intermediate filaments.
cellular system that consists of the nuclear envelope, endoplasmic reticulum, Golgi apparatus, and vesicles
system of membranous saccules and channels in the cytoplasm, often with attached ribosomes
explanation of the evolution of eukaryotic organelles by phagocytosis of prokaryotes
A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Excludes bacteria
small, bristlelike fiber on the surface of a bacterial cell, which attaches bacteria to a surface; also fingerlike extension from the oviduct near the ovary
a lash-like appendage used for locomotion (e.g., in sperm cells and some bacteria and protozoa)
Gel like coating on the outside of a bacterium. If compact it is called a capsule, if diffuse it is called a slime layer
organelle consisting of sacs and vesicles that process, packages and distributes molecules about or from the cell
Ropelike assemblies of fibrous polypeptides in the cytoskeleton that provide support and strength to cells; so called because they are intermediate in size between actin filaments and microtubules.
membrane bounded vesicle that contains hydrolytic enzymes for digesting macromolecules and bacteria, used to recycle worn out cellular organelles
Unstructured semifluid substance that fills the space between cells in connective tissues or inside organelles.
Small, cylindrical organelle composed of tubulin protein around an empty central core; present in the cytoplasm, centrioles, cilia, and flagella.
membrane-bounded organelle in which ATP molecules are produced during the process of cellular respiration
protein that moves along either actin filaments or microtubules and translocates organelles
name for the phospholipid double membrane that separates the contents of the nucleus from the cytoplasm
opening in the nuclear envelope that permits the passage of proteins into the nucleus and ribosomal subunits out of the nucleus
Where the DNA is concentrated in the prokaryotic cell; no membrane separates this region from the rest of the cell
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
membrane surrounding the cytoplasm that consists of a phospholipid bilayer with embedded proteins; functions to regulate the entrance and exit of molecules from a cell
organelles of plants and algae that are bounded by a double membrane and contain internal membranes and/or vesicles (chloroplasts, chromoplasts, 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.
sequence of amino acids that binds with a signal recognition particle (srp) causing a ribosome to bind to the endoplasmic reticulum
membranous system of tubules, vesicles, and sacs in eukaryotic cells; lacks attached ribosomes
Opening in the underside of a leaf epidermis that allows carbon dioxide and oxygen to (gases) diffuse into and out of the leaf
surface to area to volume ratio
For any cell, organism, or geometrical solid, the ratio of surface area to volume; this is an important factor in setting an upper limit on the size a cell or organism can attain.
flattened sac within a granum whose membrane contains chlorophyll and where the light reactions of photosynthesis occur.
membrane bounded sac, larger than a vesicle, usually functions in storage and can contain a variety of substances, in plants the vacuole fills much of the interior of the cell