cell
collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic units of all forms of life
cell theory
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 living cells
cell membrane
thin, flexible barrier around a cell; regulates what enters and leaves the cell
cell wall
strong supporting around the cell membrane in plants, algae, and some bacteria
nucleus
the center of the atom which contains the protons and neutrons, structure that contains the genetic material(DNA) and controls the cells activities
cytoplasm
material inside cell membrane- not including nucleus
prokaryote
unicellular organism without a nucleus
eukaryote
organism whose cells contain a nuclei
organelle
specialized structure that preforms important cellular functions within a eukaryotic cell
chromatin
the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA.
chromosome
a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
nuclear envelope
the double membrane structure that surrounds the nucleus in eukaryotic cells and provides this compartmentalization.
cytoskeleton
a microscopic network of protein filaments and tubules in the cytoplasm of many living cells, giving them shape and coherence.
microtubule
a microscopic tubular structure present in numbers in the cytoplasm of cells, sometimes aggregating to form more complex structures.
microfilament
a small rodlike structure, about 4–7 nanometers in diameter, present in numbers in the cytoplasm of many eukaryotic cells.
ribosome
a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
endoplasmic reticulum
a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis.
Golgi apparatus
a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport.
lysosome
an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.
vacuole
a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid.
cytoplast
the intact cytoplasmic content of a single cell.
mitochondria
an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae).
cell specialization
Unicellular organisms are composed of a single cell. Multicellular organisms are composed of many specialized cells. Specialized cells differ in structure (size, shape...) and function (the role they perform in the organism).
tissue
any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products.
organ
a part of an organism that is typically self-contained and has a specific vital function, such as the heart or liver in humans.
organ system
In biology, an organ system is a group of organs that work together to perform one or more functions. Organs make up an organism. In the human body, major systems are the circulatory system, the respiratory system, the nervous system and the digestive system.