cell transport passive and active transport. 1.all cells have a cell membrane a.functions: o...
TRANSCRIPT
1.All cells have a cell membrane
a.Functions: o Controls what enters and exits
the cello Provides protection and
support for the cell
About Cell Membranes
About Cell Membranes (continued)
2. Structure of cell membrane
a.The cell membrane is made of two layers of phospholipids called the lipid bilayer
b.Proteins are also embedded in cell membrane
Phospholipid
Lipid Bilayer
About Cell Membranes (continued)
3. Cell membranes have pores (holes) in ita. the holes or pores makes the cell
membrane Selectively permeable: or Allows some molecules in and keeps other molecules out
Pores
Outside of cell
Inside of cell (cytoplasm)
Lipid Bilayer
Proteins
Transport Protein Phospholipids
Carbohydratechains
Structure of the Cell Membrane
Go to Section:
Animations of membrane
structure
1. Passive Transport cell doesn’t use energyHIGH low concentrations
2. Active Transportcell does use energyLOW high concentrations
Types of Cell Transport
Passive Transport
Characteristics cell uses no energy molecules move
randomly Molecules spread out
from an area of high concentration to an area of low concentration.
(HighLow)
3 Different Types1. Diffusion2. Facilitated
Diffusion3. Osmosis
Concentration gradient- the difference in concentration of solutes or particles in different places
Concentration Gradient
1. Diffusion1. Diffusion: random movement
of particles from an area of HIGH concentration to an area
of low concentration. Diffusion continues until all
molecules are evenly spaced or have reached equilibrium
http://bio.winona.edu/berg/Free.htm
Simple Diffusion Animation
Facilitated diffusion Facilitated diffusion happens when specific particles move through proteins found in the membrane It is diffusion with the HELP of proteins
in the membrane
2. Facilitated Diffusion
Osmosis Osmosis is ONLY the diffusion of waterwater through a selectively permeable membraneWater moves from high to low high to low concentrations
Osmosis animation3. Osmosis
Solute – a SUBSTANCE dissolved in a fluid
Solvent – the FLUID part of a solution
Solution – a MIXTURE of two or more substances (a solute and solvent)
Solute/Solvent/Solution
This is sugar water.
What is the solute? What is the solvent? What is the whole
mixture called?
Solute/Solvent/Solution
A glass of iced tea.
What is the solute? What is the solvent? What is the whole mixture called?
Solute/Solvent/Solution
Ex: Dr. Pepper
What is the solute(s)? What is the solvent? What is the whole mixture called?
Solute/Solvent/Solution
HypotonicHypotonic: : A solution that has a lot of water and that water moves INSIDE the cell making it swell
Hypotonic Solution• Osmosis
Animations for isotonic, hypertonic,
and hypotonic solutions
Hypertonic: The solution has MORE solutes and a lower concentration of water
The water will move OUT of the cell making it shrink or crenate
Hypertonic Solution• Osmosis
Animations for isotonic, hypertonic,
and hypotonic solutions
shrinks
Isotonic: The concentration of solutes and water in solution and in the cell are EQUAL
Water moves equally in both directions and the cell remains same size!
Isotonic Solution
• Osmosis Animations for
isotonic, hypertonic, and hypotonic
solutions
Overcoming Osmosis
Contractile vacuoles – structure that will expel excess water from unicellular organisms that live in water. (like Paramecium!)
Turgor pressure – water pressure in a plant cell when a plant is placed in a HYPOtonic solution. A loss of turgor pressure causes wilting (plasmolysis).
Paramecium (protist) removing excess water video
Active Transport
Characteristics • cell uses energy
• actively moves molecules to where they are needed
• Movement from an area of low concentration to an area of high concentration
• Goes AGAINST the concentration gradient
2 Types of Active Transport
1. Endocytosis2. Exocytosis
Types of Active Transport
1. Endocytosis: taking bulky material
into a cell •Uses energy•Cell membrane fold in around food particle•forms food vacuole & digests food•This is how white blood cells eat bacteria!
Types of Active Transport
2. Exocytosis “leaving the cell”
Forces material out of cell in bulk• membrane surrounding
the material fuses with cell membrane
• Cell changes shape – requires energy
• EX: materials or wastes are released from cell
Endocytosis & Exocytosis animations