Post on 18-Dec-2015
Organism made from just one cell
Unicellular
All prokaryotesare unicellular
A few eukaryotes are
unicellular
Organism made from many cells that are specialized
Multicellular
Multicellular, eukaryotic, specialized. Obtain glucose from other organisms; no cell walls.
Animal Cells
Multicellular, eukaryotic, specialized. Make their own glucose; have chloroplasts and cell walls.
Plant Cells
Multicellular, eukaryotic, specialized; obtain glucose from other organisms; have cell walls.
Fungal Cells
Eukaryotic; may be multicellular or unicellular. Have cells walls. No specialization. Some “eat”, others make their own
glucose.
Protist Cells
Unicellular, prokaryotic. No specialization. Have cell wall. Some “eat”, others make their own glucose.
Bacteria Cells
Regulates the exchange of solute particles between the cell and its liquid environment. Electrically neutral (no charge). Permeable to water and small molecules; impermeable to
large/charged molecules.
Cell Membrane
Copyright Pearson Prentice Hall
Cell membrane
Supporting layer around some CMs. Has pores; allows solute particles to reach the CM, but does not regulate them
Cell Wall
Cell membrane
Solute
A substance that can dissolve in water(Ex: salt, glucose, O2, CO2). Some solute particles are charged (Na+, Cl-)
Solution
A mixture of water and dissolved solute(Ex: plasma)
Concentration
The amount of solute dissolved in a liquid. Mass/volume. Concentration of solute inside and outside a cell are different.
Ex: CO2 more concentrated outside a cell; salt more concentrated outside the cells of marine animals
Less concentrated
More concentrated
Fluid portion of the blood; a solution of water + dissolved solute; located on both sides of the CM; CM’s are in constant
contact with it
Plasma
Ion
Particles of solute that have an electric charge (Ex: K-, Na+). Cannot pass directly through the neutral CM; must go
through protein gates/pumps
Bilayer
Two layers (bi = two)
Plasma
Plasma
Diffusion
The movement of solute molecules from an area of high concentration to an area of low concentration. Does not
require energy. Uses a permeable membrane.
Permeable membrane
Side A More Solute
Side B Less Solute
= water molecule
= solute molecule
Osmosis
The diffusion of water molecules. Also moves from H -> L; does not require energy. Uses a selectively permeable
membrane. Water always moves to area with more solute.
Selectively Permeable membrane
Side A Less Water
Side B More water
= water molecule
= solute molecule
Isotonic
Concentration of solute inside and outside cell are equal. Water moves in both directions; cell does not change shape.
= water molecule
= solute molecule
Hypertonic Solution
Concentration outside cell is higher than inside cell. Water moves out of the cell; cell shrinks. Ex: goldfish in sea water.
= water molecule
= solute molecule
Hypotonic Solution
Concentration inside cell is higher than outside cell. Water moves into the cell; cell expands. Ex: shark in fresh water.
= water molecule
= solute molecule
Facilitated Diffusion
Diffusion of large/charged molecules through protein channels embedded in the CM. Still H -> L; does not require
energy.
Active Transport
“Pumping” molecules against diffusion. Moves L -> H; requires energy (to change shape of protein). Ex: “pumping”
CO2 out of cell; endocytosis, exocytosis
Endocytosis
A form of active transport; taking a substance into the cell. Requires energy (cell changes shape). Phagocytosis: food;
pinocytosis: liquid.