Chapter Three Flashcards
Plasma Membrane
The boundary of the cell
Nucleus
The center of the cell
Includes:
Nuclear Envelope
Nuclear Pores
Nucleolus
Cytoplasm
Gel-like substance surrounding the nucleus and packed with various organelles and molecules which each serve a specific function
Plasma Membrane
Surrounds the cell
-Regulates the passage of substances in and out of the cell
Selective Permeability
Some substances, like lipid-soluble molecules, pass through easily, whereas others do not.
Nuclear Envelope
Double layered membrane surrounding the nucleus
Nuclear Pores
Regulate the passage of molecules into the nucleus, as well as out of the nucleus
Chromatin
Thread like structures composed of DNA and protein
Chromosomes
When chromatin coils tightly into short rod like structures
Nucleolus
The center of the nucleus
Ribosomes
Cell’s protein production structures
How many feet of DNA is in a human body?
More than 6ft or 2m
Cytoplasm
Gel like substance that fills the space between the plasma membrane and the nucleus
Endoplasmic Reticulum
Network of membranous canals and curving sacs
Rough has ribosomes
Smooth does not
Passive Transport
Doesn’t require the cells to expend energy to transport (diffusion, osmosis, filtration, facilitated diffusion)
Diffusion
The movement of particles from an area of higher concentration to an area of lower concentration
Equilibrium
The point at which no further diffusion occurs
Concentration Gradient
A difference in concentration of a substance from one point to another
Osmosis
The diffusion of water down the concentration gradient through a selectively permeable membrane
Hydrostatic Pressure
As the volume of water on side B increases, it exerts more and more pressure against the membrane
Osmotic Pressure
Water pressure that develops in a solution as a result of osmosis
Tonicity
The ability of a solution to affect the fluid volume and pressure in a cell through osmosis
Isotonic
The concentration of solutes is the same as it is in the cell
Hypertonic
The solution contains a higher concentration of solutes compares with the fluid within the cell
Hypotonic
The solution contains a lower concentration of solutes compared to the fluid within the cell
Filtration
Water and dissolved particles are forced across a membrane from an area of higher to lower hydrostatic pressure
Facilitated Diffusion
Other molecules help (or facilitate) the movement across a membrane. The molecules move down the concentration gradient, from higher to lower concentration.
Active Transport
Solutes move up the concentration gradient, from areas of lesser to greater concentration
Sodium-Potassium Pump
(Most Important Example)
This crucial pump regulates the volume of fluid within the cells, provides the electrical potential necessary for nervous system activity, and helps in heat production
Lyses
Swelling and bursting
Endocytosis
Form of vesicular transport that brings substances INTO the cell
Phagocytosis
(cell eating)
Occurs when the cell engulfs a solid particle and brings it into the cell
Pinocytosis
(cell drinking)
Occurs when tiny vacuoles bring droplets of extracellular fluid containing dissolved substances into the cell
Exocytosis
Uses vesicles to release substances OUTSIDE of the cell
