Cell structure and Function Grid

Cell

The basic unit of life, consisting of cytoplasm enclosed within a membrane and containing genetic material. Cells can be prokaryotic or eukaryotic, performing essential functions for living organisms.

Cell Theory

The scientific theory that states all living organisms are composed of one or more cells, that the cell is the basic unit of life, and that all cells arise from pre-existing cells.

Cell Membrane

The semi-permeable membrane surrounding the cell, composed of a phospholipid bilayer with embedded proteins, which controls the movement of substances in and out of the cell.

Nucleus

The membrane-bound organelle within a cell that contains the genetic material (DNA) and regulates gene expression and cell division.

Eukaryote

An organism whose cells have a nucleus enclosed within membranes, distinguishing them from prokaryotes.

Prokaryote

A unicellular organism that lacks a membrane-bound nucleus and organelles, such as bacteria and archaea.

Cytoplasm

The gel-like substance within a cell that surrounds the nucleus and organelles, providing support and facilitating biochemical reactions.

Organelle

A specialized structure within a cell that performs distinct functions, such as energy production or protein synthesis.

Vacuole

A membrane-bound sac within a cell that stores substances such as nutrients, waste products, or cell sap. Vacuoles play a key role in maintaining turgor pressure in plant cells.

Lysosome

a cell organelle containing enzymes that digest particles and that disintegrate the cell after its death

Cytoskeleton

a shifting lattice arrangement of structural and contractile components distributed throughout the cell cytoplasm, composed of microtubules, microfilaments, and larger filaments, functioning as a structural support and transport mechanism

Centriole

a small, cylindrical cell organelle, seen near the nucleus in the cytoplasm of most eukaryotic cells, that divides in perpendicular fashion during mitosis, the new pair of centrioles moving ahead of the spindle to opposite poles of the cell as the cell divides: identical in internal structure to a basal body.

Ribsome

a tiny, somewhat mitten-shaped organelle occurring in great numbers in the cell cytoplasm either freely, in small clusters, or attached to the outer surfaces of endoplasmic reticula, and functioning as the site of protein manufacture.

Endoplasmic Reticulum

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

Golgi Apparatus

Golgi Body

Chloroplast

a plastid containing chlorophyll

Mitochondrion

the singular of mitochondria.

Cell Wall

the definite boundary or wall that is part of the outer structure of certain cells, as a plant cell

Lipid Bilayer

a thin, flexible, two-layer membrane that makes up the outer boundary of all living cells and many cellular components

Selectively Permeable

a barrier that allows some molecules or ions to pass through while blocking others

Homeostasis

the tendency of a system, especially the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function.

Tissue

an aggregate of similar cells and cell products forming a definite kind of structural material with a specific function, in a multicellular organism

Organ

a grouping of tissues into a distinct structure, as a heart or kidney in animals or a leaf or stamen in plants, that performs a specialized task.

Organ System

a group of anatomical organs that work together to perform one or more major functions in a multicellular organism

Receptor

any of various specific protein molecules in surface membranes of cells and organelles to which complementary molecules, as hormones, neurotransmitters, antigens, or antibodies, may become bound.