Cells Are Us!

Vacuole

Cell structure that stores materials such as water, salts, proteins, and carbohydrates.

Eukaryotic cell

Cells with a membrane-bound nucleus and other membrane-bound organelles such as mitochondria. The DNA of these more complex cells is usually found as multiple chromosomes.

Prokaryotic cell

Cells without a membrane-enclosed nucleus found in the domains Bacteria and Archaea. DNA of these simple cells is usually found as one circular chromosome loosely organized toward the center of the cell.

Centrioles

Centrioles (found only in animal cells) create microtubules that assist in chromosome separation during cell division.

Peroxisomes

Found in all cells but especially abundant in liver and kidney cells where this organelle neutralizes free radicals, detoxifies alcohol and other drugs. Peroxisomes also break down fatty acids which mitochondria uses for energy.

Chloroplast

Found only in plant and algae cells, he chloroplast contains thylakoid stacks which hold the light absorbing pigments for photosynthesis. Like the mitochondria, the chloroplast has it's own circular DNA genome which makes some of the enzymes that it uses The chloroplast DNA is replicated separately from the DNA found in the nucleus.

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Flagella

Long whip-like structures connected at the surface of a cell membrane that help cell which have flagella to move through liquids.

Organelle

A membrane-enclosed structure with a specialized function within a cell.

Endoplasmic reticulum

A membranous structure with both smooth and rough sections (see additional definitions for smooth ER and rough varieties). The ER is connected to the nuclear membrane and forms a maze of passageways that act like a transportation system to traffic proteins and other materials from one part of the cell to another.

Cell membrane

A phospholipid bilayer containing proteins and lipids that acts as a barrier between the inside of a cell and the cell's environment. The cell membrane functions in transportation, attachment, the recognition and reception of chemical/protein signals from both inside and outside the cell.

Cell wall

A protective layer outside of the cell membrane in plant cells, bacteria, and a some other cells. The cell wall provides structure determining the shape of a cell.

Plasmid

A small circular DNA molecule found in some bacteria that replicates independently of the chromosome. By welcoming a plasmid into its cytosol, a bacterial cell might gain extra abilities not found in its own DNA genome.

Ribosomes

A small grain-like organelle composed of proteins and ribosomal RNA. Found in the cytoplasm of a cell attached to the rough ER or freely floating, these organelles are the 'factory' where proteins are made.

Lysosome

A small, round organelle containing acidic enzyme proteins that break down large food particles into smaller ones.

Golgi apparatus

A stack of membrane-bound discs that modify, sort, and package proteins and other large molecules produced by the cell.

Nucleoid

Area in prokaryotic cells in which DNA is concentrated; the nucleoid is NOT enclosed by a membrane.

Smooth endoplasmic reticulum

Smooth ER looks much like system of interconnected tubes. In this smooth ER network, phospholipids and steroids are synthesized and carbohydrates are metabolized.

Cytoplasm

The jelly-like fluid AND the organelles within the cell membrane.

Nucleus

The nucleus is the site for storage and replication of DNA in eukaryotes. Enclosed in a double membrane (the nuclear envelope), with pores that allow only specific molecules to pass between the nucleus and cytoplasm. The nucleolus is found within the nucleus.

Nucleolus

The organelle inside the nucleus, where ribosome components are synthesis.

Mitochondria

The organelle responsible for cellular respiration - a reaction that creates usable energy for the cell in the form of ATP . These organelles have different ribosomes than the cell and their own circular DNA genome which inherited ONLY from the mother.

Rough endoplasmic reticulum

The rough ER looks like a series of flattened sacs with ribosomes sprinkles on their surfaces Rough ER manufactures and packages proteins.

Cytosol

The soluble portion of the cytoplasm, which includes molecules and small particles, such as ribosomes, but not the organelles covered with membranes.