Anatomy and Physiology Notes
Notes: Anatomy & Physiology 1. Cells
A cell is the basic, living, structural, and functional unit of the body.
Cytology: the study of cells
A generalized view of the cell
3 main parts of the cell: Plasma membrane, cytoplasm and nucleus. * Plasma (cell) membrane: * Outer, limiting membrane separating the cell `s internal components from the extracellular materials and external environment. * Cytoplasm (formed or molded): * Consist of all the cellular contents between the plasma membrane and the nucleus. * Cytoplasm can be divided into: cytosol and organelles * Cytosol: the thick, semifluid intracellular fluid is termed the cytosol. The cytosol contains many dissolved proteins and enzymes, nutrients, ions, and other small molecules, which all participate in various phases of metabolism. * Organelles: Highly organized structures with characteristic shapes that are specialized for specific cellular activities. The organelle with the largest volume is the nucleus, which contains most of a cell`s genetic material. * Inclusions: Temporary structures in the cytoplasm that contains secretions and storage products of the cell.
Plasma (cell) membrane
The thin barrier that separates the internal components of a cell from extracellular materials is the plasma membrane, also called the cell membrane. The plasma membrane is the gatekeeper that regulates passage of substances into and out of the cell.
Membrane Chemistry and Anatomy
Plasma membranes of typical animal cells are about a 50:50 mix by weight of proteins and lipids that are held together by noncovalent interactions. Since proteins are larger and more massive than lipids, however, there are about 50 lipid molecules for each protein molecule.
Membrane Lipids
About 75% of the lipids are phospholipids, lipids that contain phosphorus. Present in smaller amounts are cholesterol (a steroid) and glycolipids, which are lipids with one or more
A cell is the basic, living, structural, and functional unit of the body.
Cytology: the study of cells
A generalized view of the cell
3 main parts of the cell: Plasma membrane, cytoplasm and nucleus. * Plasma (cell) membrane: * Outer, limiting membrane separating the cell `s internal components from the extracellular materials and external environment. * Cytoplasm (formed or molded): * Consist of all the cellular contents between the plasma membrane and the nucleus. * Cytoplasm can be divided into: cytosol and organelles * Cytosol: the thick, semifluid intracellular fluid is termed the cytosol. The cytosol contains many dissolved proteins and enzymes, nutrients, ions, and other small molecules, which all participate in various phases of metabolism. * Organelles: Highly organized structures with characteristic shapes that are specialized for specific cellular activities. The organelle with the largest volume is the nucleus, which contains most of a cell`s genetic material. * Inclusions: Temporary structures in the cytoplasm that contains secretions and storage products of the cell.
Plasma (cell) membrane
The thin barrier that separates the internal components of a cell from extracellular materials is the plasma membrane, also called the cell membrane. The plasma membrane is the gatekeeper that regulates passage of substances into and out of the cell.
Membrane Chemistry and Anatomy
Plasma membranes of typical animal cells are about a 50:50 mix by weight of proteins and lipids that are held together by noncovalent interactions. Since proteins are larger and more massive than lipids, however, there are about 50 lipid molecules for each protein molecule.
Membrane Lipids
About 75% of the lipids are phospholipids, lipids that contain phosphorus. Present in smaller amounts are cholesterol (a steroid) and glycolipids, which are lipids with one or more