Organelle Info Organelles – the tiny structures insides a cell (tiny “organs”) 1. Cell Wall – Only found in a plant cell, and provides the plant cell with support and protection. Made with cellulose, which is a non-living, undigestible material. 2. Cell Membrane – Is the outer boundary of an animal cell, and just under the cell wall of an plant cell. The cell membrace is porous (full of small openings) to allow materials in and out of the cell. The cell membrane is flexible and allows the cell to change shape under pressure, much like a water balloon. 3. Nucleus – is often called the “brain” of the cell, and control’s the cell’s activities. It contains the cell’s chromosomes, or genetic material. 4. Chromosomes – are strands of genetic material (DNA) within the nucleus which contain all the information about the living thing they are part of. Human cells contain 23 pairs (46 altogether) chromosomes in the nucleus of each of their body cells. 5. Nucleolus – is a round structure within the nucleus. Its purpose isn’t totally understood, however, it is believed that ribosomes are produced here. 6. Nuclear membrane – is the outer boundary of the nucleus and, like the cell membrane, allows materials to pass in and out tof the nucleus. 7. Endopalsmic reticulum – is a network of tubular passageways in the cell which is used to transport materials within the cell. Often ribosomes are attached to the inner walls of the E.R. 8. Ribosomes – produce protein within the cell. Proteins are used to build and repair cellular material. Ribosomes may be free-floating in the cytoplasm, or attached to the E.R.’s wall. 9. Mitochondria – are often called the powerhouse if the cell, since they supply energy to the cell. They turn the energy from our food into energy the cell can use. The more active a cell is, the more mitochondria it contains. 10. Vacuoles – are storage tanks for the cells. Vacuoles may store water, food or wastes. In a plant cell, there is often one large vacuole whose purpose is to store water, and help keep the plant from wilting (drooping). Plant cells with little water in this vacuole tend to look droopy (wilted). 11. Lysosomes – are often referred to as the cell’s digestive system, since it contains enzymes (chemicals) that break materials down. Sometimes lysosomes are also referred to as “suicide sacs”, since dying cells often release these enzymes to help break themselves down within the body. 12. Chloroplasts – are only in plant cells. They are in charge of performing photosynthesis (food production) within the plant cells. They contain a green pigment called chlorophyll, which is responsible for the green coloring in many plants.