Biology Cell Terms

Active Transport

Movement of substances across a plasma membrane that requires energy

Cell Membrane

to be a barrier keeping the constituents of the cell in and unwanted substances out and, second, to be a gate allowing transport into the cell of essential nutrients and movement from the cell of waste product - made up of a lipid bilayer that is semi-permeable

Cell Theory

theory that all living things are made up of cells, all life functions occur within cells, and all cells come from already existing cells

Cell Wall

 rigid layer that surrounds the plasma membrane of a plant cell and helps support and protect the cell

Central Vacuole

large saclike organelle in plant cells that stores substances such as water and helps keep plant tissues rigid

Chloroplast

organelle in the cells of plants and algae where photosynthesis takes place

Cilia

short, hairlike projections, similar to flagella, that allow some cells to move

Cytoplasm

All of the material inside the plasma membrane of a cell (excluding organelles)

Cytoskeleton

structure of filaments and tuubues in the cytoplasm that provides a cell with an internal framework

Diffusion

type of passive transport that does not require the help of transport proteins

Electron Microscope

uses a beam of electrons and their wave-like characteristics to magnify an object’s image

Endocytosis

Type of vesicle transport that moves substances into a cell

Endoplasmic Reticulum

organelle in eukaryotic cells that helps make and transport proteins

Exocytosis

type of vesicle transport that moves substances out of a cell

Eukaryote

organism that has cells containing a nucleus and other organelles

Facilitated Diffusion

Diffusion with the help of transport proteins

Flagella

long, thin protein extensions of the plasma membrane in most prokaryotic cells that help the cells move

Golgi

organelle in eukaryotic cells that processes proteins and prepares them for use both inside and outside the cell

Robert Hooke

For his first use of the word cell in the sense of a basic unit of organisms

Hypertonic

A hypertonic solution has a higher solute concentration compared to the intracellular solute concentration

Light Microscope

an instrument for visualizing fine detail of an object

Lipid Bilayer

fluid, with individual lipid molecules able to diffuse rapidly within their own monolayer

Lysosome

Membrane enclosed organelles that contain an array of enzymes capable of breaking down all types of biological polymers like proteins, nucleic acids, carbohydrates, and lipids

Maginfication

The ability of a microscope to produce an image of an object at a scale larger (or even smaller) than its actual size

Mitochondria

organelle in eukaryotic cells that makes energy available to the cell in the form of ATP molecules

Nucleus

Organelle inside eukaryotic cells that contains most of the cell’s DNA and acts as the control center of the cell

Organelle

sturcture within the cytoplasm of a cell that is enclosed within a membrane and performs a specific job

Osmosis

diffusion of water molecules across a membrane

Passive Transport

movement of substances across a plasma membrane that does not require energy

Phospholipid

major membrane lipids that consist of lipid bilayers. This basic cellular structure acts as a barrier to protect the cell against various environmental insults and more importantly, enables multiple cellular processes to occur in subcellular compartments.

Prokaryote

single celled organism that lacks a nucleus

Resolution

The ability of a microscope to distinguish details of a speciman or sample

Ribosome

Organelle inside all cells where proteins are made

Scanning Tunneling Microscope

It can be used to image topography measure surface properties, manipulate surface structures and to initiate surface reactions

Vesicle

small saclike organelle that stores and transports materials inside a cell