Chapter 4 Cell structure & function Flashcards
Cell function & function
actin filaments
Filaments composed of the protein actin that are part of a cell’s cytoskeleton
active transport
The use of a carrier molecule to move molecules across a plasma membrane in a direction opposite that of the concentration gradient. The carrier requires an input of energy other than the kinetic energy of the molecules.
aerobic cellular respiration
The biochemical pathway that requires oxygen and converts food, such as carbohydrates, to carbon dioxide and water. During this conversion, it releases the chemical-bond energy as ATP molecules.
antibiotics
Drugs that selectively kill or inhibit the growth of a particular cell type
Archaea
One of two domains of prokaryotic organisms: Archaea and Bacteria. Distinguished from the domain Bacteria by differences in the nature of the DNA, cell wall, and cell membrane.
Bacteria
Noneukaryotic, unicellular organisms of the Domain Bacteria; formerly used to refer to members of both the Domain Bacteria and the Domain Archaea.
cells
The basic structural units of all living things; the smallest units that display the characteristics of life.
cell theory
The concept that all living things are made of cells.
cell wall
An outer covering on some cells; may be composed of cellulose, chitin, or peptidoglycan, depending on the kind of organism.
cellular membranes
Thin sheets of material composed of phospholipids and proteins; some of the proteins have attached carbohydrates or fats.
centriole
Two sets of nine short microtubules; each set of tubules is arranged in a cylinder.
chlorophyll
The green pigment located in the chloroplasts of plant cells associated with trapping light energy.
chloroplasts
Energy-converting, membranous, saclike organelles in plant cells containing the green pigment chlorophyll.
chromatin
An area or a structure within the nucleus of a cell composed of long molecules of deoxyribonucleic acid (DNA) in association with proteins.
chromosome
Double stranded DNA molecules with attached protein (nucleoprotein) coiled into a short, compact unit.
cilia
Numerous short, hair-like structures projecting from the cell surface that enable locomotion.
concentration gradient (diffusion gradient)
The gradual change in the number of molecules per unit of volume over distance.
cristae
Folded surfaces of the inner membranes of mitochondria.
cytoplasm
The portion of the protoplasm that surrounds the nucleus.
cytoskeleton
The internal framework of eukaryotic cells composed of intermediate filaments, microtubules, and microfilaments; provides the cell with a flexible shape, and the ability to move through the environment, to move molecules internally, and to respond to environmental changes.
diffusion
The net movement of a kind of molecule from an area of higher concentration to an area of lesser concentration.
domain
The first (broadest) classification unit of organisms; there are three domains: Bacteria, Archaea, and Eucarya.
dynamic equilibrium
The condition in which molecules are equally dispersed; therefore, movement is equal in all directions.
endocytosis
The process cells use to wrap membrane around a particle (usually food) and engulf it.
endoplasmic reticulum (ER)
Folded membranes and tubes throughout the eukaryotic cell that provide a large surface on which chemical activities take place.
Eucarya
The domain of life that includes all organisms that have eukaryotic cells (plants, animals, fungi, protozoa, and algae).
eukaryotic cells
One of the two major types of cells; cells that have a true nucleus, as in plants, fungi, protists, and animals.