Notes

Cell Structure: There are many different types, sizes, and shapes of cells in the body. For descriptive purposes, the concept of a generalized cell is introduced. It includes features from all cell types. A cell consists of three parts: the cell membrane, the nucleus, and the cytoplasm. Within the cytoplasm, arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles. Cells are the Starting Point Structure of generic animal cell. All living organisms on Earth are divided into cells. The main concept of cell theory is that cells are the basic structural unit for all organisms. Cells are small compartments that hold the biological equipment necessary to keep an organism alive and successful. Living things may be single-celled or they may be very complex such as a human being.

Cell Membrane: The cell membrane is a thin semi-permeable membrane that surrounds the cytoplasm of a cell. Its function is to protect the integrity of the interior of the cell by allowing certain substances into the cell, while keeping other substances out. It also serves as a base of attachment for the cytoskeleton in some organisms and the cell wall in others. Thus the cell membrane also serves to help support the cell and help maintain its shape. Animal cells , plant cells , prokaryotic cells, and fungal cells have cell membrane.

Cell Wall: While cell membranes might be around every cell, cell walls made of cellulose are only found around plant cells. Cell walls are made of specialized sugars called cellulose. Cellulose provides a protected framework for a plant cell to survive. Cellulose is called a structural carbohydrate (complex sugar) because it is used in protection and support.

Cytoplasm: Cytoplasm is the fluid that fills a cell. Scientists used to call the fluid protoplasm. Early on, they didn't know about the many different types of fluids in the cell. There is special fluid in the mitochondria, endoplasmic reticulum, Golgi apparatus, and nucleus. The only two fluids in the cells left are cytoplasm and nucleoplasm. Each of those fluids has a very different composition.