Cells and Their Functions

Functional Anatomy of Cells Eukaryotic or Prokaryotic cells have three alike cellular structures. Nucleus, Plasma Membrane, and Cytoplasm.

Plasma Membrane Separates the cell from its surrounding environment. Gives cell small amounts of support.

Cytoplasm Thick gel-like substance inside of the cell composed of numerous organelles suspended in watery cytosol.

Nucleus Large membranous structure near the center of the cell. Contains chromosomes, all hereditary information of the body.

Cell Membranes Each cell contains a variety of membranes The first type is a plasma membrane. The second is membranous organelles. Most cell membranes have a double layer of phospholipid molecules.

Cytoplasm and Organelles Cytoplasm is a gel-like internal substance of cells that includes many organelles suspended in watery intracellular fluid.

Organelles Organelles are broken down into two categories: - membranous organelles, which are specialized sacs or canals made of cell membranes. - Nonmembranous organelles are made of microscopic filaments.

Membranous Organelles Endoplasmic Reticulum is made of membranous curved sacs, arranged in parallel rows. Proteins move through these curved sacs. There are two types of endoplasmic reticulum: Rough and Smooth

Rough ER Ribosomes cover the outside of Rough ER This helps aid in the process of protein synthesis.

Smooth ER No ribosomes border the outer walls of Smooth ER. Helps synthesize certain lipids and carbohydrates.

Golgi Apparatus Membranous organelle consisting of cisternae, stacked on one another located by the nucleus. Processes protein molecules from the ER Package molecules proteins with carbohydrates to make glycoproteins.

Lysosomes Made of microscopic membranous sacs that have pinched off from the Golgi Apparatus. The cell’s own digestive system; enzymes in lysosomes digest free floating particles in the cell, or in some instances lysosomes digest the cell, in a cell suicide.

Peroxisomes Small membranous sacs containing enzymes that detoxify the harmful substances that enter the cell. Often found near or in the kidney.

Mitochondria Powerhouse of the cell Through mitochondrial reactions, the mitochondria supplies the cell with over 95% of its energy.

Nucleus House the genetic code. Starts protein synthesis in the cell Organisizes all cell activities including, cell transport, metabolism, and growth.

Nonmembranous Organelles Ribosomes, cytoskeleton, cilia, an nucleolus are all nonmembranous cell organelles.

Ribosomes Ribosomes are found on the outer walls of Rough Endoplasmic Reticulum, and in the cytoplasm of the cell. Ribosomes are nonmembranous and are made of two pieces, a large subunit, and a small subunit. Both are made of RNA. Ribosomes are vital in protein production.

Cytoskeleton Acts as a framework to support the cell and its organelles. Functions in cell movement Forms cell extensions such as cilia or flagella.

Cell Extensions Cilia and flagella are hairlike cell extensions that serve to move the cell or propel sperm cells.

Nucleolus Part of the nucleus that plays an essential role in the formation of ribosomes.

Special Cell extensions Microvilli are cell extensions that are found in epithelial cells that line the intestines. They can also be found anywhere in the body where absorption is important.

Cell Connections Cells are held together by fibrous nets that surround groups of cells. There are three types of cell connections: desmosomes, gap junctions, and tight junctions.

Desmosomes Spot welds, that hold adjacent cells together.