Animal and Plant Cells

nucleus

A cell structure that contains nucleic acids, the chemical instructions that direct all the cell's activities. (found in plant and animal cells) You can think of the nucleus as the cell's control center, directing all of the cell's activities. You can think of the nucleus as the cell's control center, directing all of the cell's activities.

cell membrane

A cell structure that controls which substances can enter or leave the cell. (found in all cells) In cells with cell walls, the cell membrane is located just inside the cell wall. In other cells, the cell membrane forms the outside boundary that separates the cell from its environment.

endoplasmic reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another. (rough and smooth ER)

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. (found in plant cells not animal cells) The cell wall is made of a tough, yet flexible, material called cellulose.

ribosome

A small grain-like structure in the cytoplasm of a cell where proteins are made. Attached to the outer surface of the endoplasmic reticulum are small grainlike bodies called ribosomes. Other ribosomes are found floating in the cytoplasm. Ribosomes function as factories to produce proteins.

lysosome

A small round cell structure that contains chemicals that break down large food particles into smaller ones. Lysosomes are more common in animal cells than in plant cells.

Golgi bodies

A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell. (passageways) look like a flattened collection of sacs and tubes can be thought of as the cell's mailroom

chloroplast

A structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food. (many large green structures floating in the cytoplasm)

organelles

A tiny cell structure that carries out a specific function within the cell. Many cell organelles are found in the cytoplasm. The organelles function to produce energy, build and transport needed materials, and store and recycle wastes.

vacuole

A water-filled sac inside a cell that acts as a storage area. found in plant (large) and animal (smaller) cells Most plant cells have one large vacuole. Some animal cells do not have vacuoles; others do.

bacterial cells

First, bacterial cells are usually smaller than plant or animal cells. While a bacterial cell does have a cell wall and a cell membrane, it does not contain a nucleus. The bacterial cell's genetic material, which looks like a thick, tangled string, is found in the cytoplasm. Bacterial cells contain ribosomes, but none of the other organelles found in plant or animal cells.

Looking Inside Cells

Key Ideas The cell membrane protects the cell and controls what substances enter and leave it. The nucleus is the cell's control center. Organelles in the cytoplasm perform many vital functions.

mitochondria

Rod-shaped cell structures (organelles) that produce most of the energy needed to carry out the cell's functions. "powerhouses" of the cell

peroxisome

Some functions of peroxisomes include detoxifying alcohol, bile acid formation, and using oxygen to break down fats. Similar to lysosomes, peroxisomes are excellent examples of compartmentalized structure relating to cellular function.

cytoplasm

The region between the cell membrane and the nucleus; in organisms without a nucleus, the region located inside the cell membrane. clear, thick, gel-like fluid

nucleolus

Where ribosomes are made. Ribosomes are the organelles where proteins are produced.

chromatin

strands that contain the genetic material, the instructions that direct the functions of a cell.