Cell Organelles

What are organelles? A cell is the smallest unit of life. It can perform all of the functions of life. Cells are made of parts called organelles. Organelle: A structure that performs a specific function within the cell.

Cell Membrane The protective layer around all cells is called the cell membrane. The cell membrane determines what is allowed to move in or out of the cell. Water is able to move freely into and out of the cell. Food particles and some molecules move in and waste moves out through the cell membrane.

Cell Wall The cell wall is a tough rigid outer coating that protects a cell and gives it shape. Cell walls are found in plant, algae, fungi and most bacteria cells. Animal cells do not have cell walls!

Cytoplasm Cytoplasm is a jelly like substance that constantly flows within a cell. Many important chemical reactions occur here and this is where a cell’s organelles are located.

Nucleus The nucleus is the “brain” of the cell and controls most of the activities that occur within the cell. Chromosomes (long threads of DNA) are found within the nucleus.

Nucleolus and Ribosomes The nucleolus is a small object located inside of the nucleus. Ribosomes are produced inside of the nucleolus. Ribosomes are the organelles that produce proteins in a cell. (They do this with the help of DNA.) Once made, these proteins direct messages within a cell and control cell functions. Ribosomes are found either in the cytoplasm of a cell or attached to the endoplasmic reticulum of a cell.

Chloroplasts Cells require a continuous supply of energy to process food, make new substances, eliminate wastes and communicate to each other. Chloroplast are responsible for making food in a plant cell. Chloroplast contain a green pigment called chlorophyll. Chlorophyll captures light energy that is used to make a sugar called glucose. Animal cells do not have chloroplasts!

Mitochondria Mitochondria are organelles where energy (called ATP) is released from breaking down food into carbon dioxide and water. Cells that use more energy than other cells (muscle cells) usually have more mitochondria.

Endoplasmic Reticulum The Endoplasmic Reticulum are curved passageways within a cell. The E.R.’s passageways carry proteins and other materials through a cell. There are 2 types of E.R. Rough E.R.: E.R. with ribosomes attached Smooth E.R.: E.R. without ribosomes

Golgi Bodies The golgi bodies are the “shipping and packaging plant” of a cell. Think of them as the UPS of a cell. The golgi bodies receive materials from the E.R. and send them to other parts of the cell. Golgi bodies also move waste materials out of a cell.

Lysosome Lysosomes are the “trash compactors” of the cell. Lysosomes contain chemicals that break down food particles and worn out cell parts.

Vacuole A vacuole is a sac within cytoplasm that stores water, food, waste products, and other materials in a cell. They are found in both plant and animal cells, but are often MUCH larger in plant cells.