What are the 4 basic concepts of cell theory?
1. cells are the building blocks of all plants and animals
2. Cells are the smallest functioning units of life
3. Cells are produced through the division of pre-exitsting cells.
4. Each cell maintains homeostasis
The cell membrane general functions are?
Physical isolation, regulation of exchange with the environment, sensitivity, structural support
The cell membrane is extrememly thin and delicate, and ranges from 6 nm to 10 nm in thickness. This membrane contains what in the actual membrane?
lipids, proteins, and carbohydrates
The permeability of the cell membrane determines what?
Precisely which substances can enter or leace the cytoplasm
What is the difference between passive process and active process movements across the membrane?
passive requires no energy expenditure by the cell
active requires energy usually in the form of adenosine triphosphate (ATP)
What is diffusion?
It is the net movement of molecules from an area of relatively high concentration (many collisions) to an area of relatively low concentration of collisions.
What is osmosis?
The diffusion of water across a membrane toward a solution that contains relatively higher solute concentration; requires selectively permeable membrane
Three characteristics of osmosis to remember are?
Osmosis is the diffusion of water molecules across a membrane
Osmosis occurs across a selectively permeable memvrane that is feely permeable a to water but is not freely permeable to solutes
In osmosis, water flows across a membrane twoard the solution that has the higher concetrantion of solutes, cuz taht is where the concentration of water is lower
What is an isotonic solution?
it is one that does not cause a net movement of water into or out of a cell.
What is a hypotonic solution?
it allows water to flow into the cell which will cause it to swell up like a balloon and eventually burst, which is called hemolysis
What is a hypertonic solution?
It loses water by osmosis causing the cell to shrivel and dehydrate. The shrinking of red blood cells is called crenation
What happens in a carrier-mediated transport?
A membrane protein binds specific ions or organic substances and carry them across the cell membrane
What is endocytosis?
it is the packaging of extracellular materials in a vesicle at the cell surface for import INTO the cell.
There are 3 tyes of endocytosis, what are they?
What happens in the process of exocytosis?
a vesicle created INSIDE the cell fuses with th e cell membrane and discharges its contents into the extracellular environment
What happens in facilitated diffusion?
carrier proteins passively transport solutes down a concentration gradient
What is filtration?
Movement of water, ususally with solute, by hydrostatic pressure; requires filtration membrane
What is active transport?
carrier proteins actively transport solutes regardless of any concetration gradients