A&P Seeley 3.1
Plasma membrane or cell membrane
The outer boundary of the cell through which the cell interacts with its external environment.
What are the characteristics functions of the cell?
Cell metabolism and energy use
Synthesis of molecules
Reproduction and inheritance
What are gametes?
Specialized cells responsible for transmitting genetic information.
Substances inside the cell
Extracellular or intercellular
Substances outside the cell
What does the plasma membrane attach cells to?
The extracellular environment or to other cells.
The regulation of ion movement by cells results in a charge difference across the plasma membrane.
The outside of the plasma membrane is ____ charged compared with the inside.
What is the glycocalyx?
The collection of glycolipids, glycophoteins, and carbohydrates on the outer surface of the plasma membrane.
What types of molecules are found in the glycocalyx?
Molecules absorbed from the extracellular environment
What is the Lipid bilayer?
A double layer of phospholipid molecules
The predominant lipids of the plasma membrane are…
Phospholipids and cholesterol
How are the phospholipids arranged in the lipid bilayer?
The polar hydrophilic heads face inside and outside the cell.
The nonpolar hydrophobic tails face each other in the interior of the plasma membrane.
What is the function of cholesterol in plasma membranes?
It determines the fluid nature of the membrane and limits the movement of phospholipids, providing stability to the plasma membrane.
The basic structure of the plasma membrane is determined by its…
Many functions of the plasma membrane are determined by its…
Penetrate deeply into the lipid bilayer, often extending from one surface to the other.
Are attached to the inner or outer surfaces of the lipid bilayer
Cell surface molecules that allow cells to identify one another or other molecules
Proteins with attached carbohydrates
Lipids with attached carbohydrates
Allow cells to attach to other cells or to extracellular molecules
Proteins that attach cells to other cells.
Proteins that attach cells to extracellular molecules
Integral proteins that allow ions or molecules to move from one side of the plasma membrane to the other.
What type of proteins are included in transport proteins?
Channel proteins, carrier proteins, and ATP-powered pumps
One or more integral proteins arranged so that they form a tiny channel through the plasma membrane.
Which way does the hydrophobic region of the proteins face?
Outward toward the hydrophobic part of the plasma membrane
Which way does the hydrophilic region of the protein face?
Inward and line the channel
Nongated ion channels
Channel proteins that are always open and are responsible for the permeability of the plasma membrane to ions when the plasma membrane is at rest.
Gated ion channels
Protein ion channels that can be opened or closed.
Chemical signals (ligands)
Small molecules that bind to the proteins or glycoproteins
Ligand-gated ion channels
Gated ion channels that open and close in response to chemical signals (ligands)
Voltage-gated ion channels
Gated ion channels that open or close when there is a change in charge across the plasma membrane.
Carrier proteins (transporters)
Membrane proteins that move ions or molecules from one side of the plasma membrane to the other.
A&P Seeley 3.1
Anatomy & Physiology text, Seeley, Ch 3 Cell Biology & Genetics, part 1/4