1.2 Microscopes allow us to see inside the cell.

Light microscope In a light microscope, lenses are used to bend light and make objects appear bigger than they are.

Scanning Electron Microscope (SEM) The scanning electron microscope uses electrons to form a three-D image of the surface of a cell.

Transmission Electron Microscope (TEM) The transmission electron microscope uses electrons which pass through the cell to produce a two dimensional image of the inside of the cell.

Scanning electron microscopes and transmission electron microscopes can not be used on live specimens.

Micrometer One millionth of a meter.

Cytoplasm A thick gelatin-like material contained within the cell membrane. Most of the work of the cell is carried out in the cytoplasm.

Cell Membrane The outer boundary of the cytoplasm. A layer that controls what enters or leaves the cell. A protective covering enclosing the entire cell.

Eukaryotic Cell A cell in which the genetic material is enclosed within the nucleus, surrounded by its own membrane.

Nucleus The structure in a eukaryotic cell that contains the genetic material a cell needs to reproduce and function. The control center of the cell that directs all the cell’s activities.

Organelle A structure in a cell that is enclosed by a membrane that performs a certain function.

Prokaryotic Cell A cell that lacks a nucleus and other organelles, with DNA that is not organized into chromosomes.

Cell Wall A protective outer covering that lies just outside the cell membrane of plant cells.

Chloroplasts An organelle in a plant cell that contains chlorophyll, a chemical that uses the energy from sunlight to make sugar.

Mitochondria The powerhouse of the cell. Organelle that releases energy to break down sugars.

Endoplasmic Reticulum Folded membranes in the cytoplasm that transport substances made by the cell.

Ribosomes Structures in the cytoplasm that make proteins from amino acids.

Golgi Apparatus (bodies) Organelles that deliver substances released by the endoplasmic reticulum.

Vacuoles These structures include storage rooms. Some vacuoles store water for future use while some store wastes until they are removed from the body.

Lysosome Digest large particles within the cell.

Nuclear Membrane The semi-permeable membrane that separates the nucleus from the cytoplasm.

Nucleolus A small structure within the nucleus which is involved in producing proteins.

Chromosomes Structures made of nucleic acids (DNA and RNA) and proteins made up of genes

* The most obvious difference between a plant and animal cell is the size of the vacuoles. Plant cells have a large central vacuole, which still acts as a storage area.

Plant cells also have a thick firm boundary called the cell wall. The cell wall supports and protects the cell. The ability to make its own food is one of the most

Important plant life processes as well as a major difference between plant and animal cells. In the cytoplasm of a plant cell are many small green structures called chloroplasts.

Chloroplasts contain molecules of chlorophyll which allows a plant cell to make its own food.