Cell Membrane

Fluid Mosaic Model

fluid mixed composition of phospholipid

Adhesion Proteins

proteins that are embedded in the plasma membrane

Communication Proteins
allow substances to move from one cell to another

Receptor Proteins

combine with extracellular substances

Recognition Proteins

recognize what can enter or not enter the cell

Passive Transporters

have channels in their interior, no needs input of energy
Active Transporters

transporters that need input of energy and move against the core gradient

Concentration Gradient

is a difference in the number per unit volume of molecules

Diffusion

is the name for the net movement of like molecules or ions

Electric Gradient

is simply a difference in electric charge between adjoining regions

Pressure Gradient

pressure exerted per unit volume between two adjoining regions
Osmosis

is the diffusion of water across a selesctively permeable membrane

Hypotonic Solution

is the solution with fewer solutes
Hypertonic Solution
solution with more than one solutes
Isotonic Solution
solution that show no net osmotic movement
Hydrostatic Pressure

turger pressure
Osmotic Pressure

measure of the tendency of water to follow its water concentration
Endocytasis
a small patch of plasma membrane inside the cytoplasm
Exocytasis
a vesicles moves to the cell surface
Phagocytosis

cell eating. Is a common endocytic pathway

Cell Structure and Function

Nucleoid

region of the cytoplasmthat is not enclosed in a membrenous sac.

Lipid Bilayer

a continous, oily boundary that prevents the free passage of water soluble substance across it
Wavelenght

distance from the peak of one way to the peak behind it
Electron Microscope

uses magnetic lenses to bend and diffract beams of electrons
Transmision Electron Microscope

electron pass through a specimen and are used to make images of its internal details
Scanning Electron Microscope

direct a beam of electrons back and forth across a surface of a specimen
Organelles

start out life with a nucleus and other membrane bounded sacs
Secretory Pathway

move polypeptide changes from one ribosome through ER and golgi body
Endocytic Pathway

move ions and molecules into the cytoplasm
Vesicles

tiny sacs
Peroxisomes

hold enzymes that digest fatty acids, amino acids, and hydrogen peroxide
Cell Junctions

molecular structure were a cell sends or receives signals of materials
Basal body

barrel shaped structure that produces and organizes microtubules
Pseudopods

false feet
Nuclear envelope

a double membrane system
Chromatin

a cell collection of DNA
Chromosome

a double-standed DNA molecule and its associated proteins