how do things move in and out of the cell? transport!
TRANSCRIPT
How do things move in and out of the cell?
TRANSPORT!
2 terms used to describe the plasma membrane are:
semi-permeable selectively permeable
Examples:• O2, CO2 (& sometimes H2O) move across the membrane
freely
• (H2O), Ions (charged molecules) and really LARGE molecules need a protein channel to help move across
* Some substances can pass across
them, and others can’t.*
Sugars & Proteins
Pass Freely Protein Channel
can also use the protein channel
Two Types:
1. Simple Diffusion2. Facilitated Diffusion
In BOTH TYPES, small ions and molecules move in/out of the cell
according to the concentration gradient
Passive Transport
Concentration GradientHIGHCONCENTRATION
LOWCONCENTRATION
Certain molecules
(like O2 and CO2 and sometimes H2O) move into/out of the cell according to the
concentration gradient
Simple Diffusion
Diffusion of specific particles through protein channels found in the membrane
Transports larger or charged molecules (ions)
Facilitated Diffusion
Much like the Shape-O toy, Transport Protein channels are specific to certain kinds (shapes) of molecules.
Each hole represents a specific protein channel
The surrounding plastic represents the
lipid bilayer
Facilitated Diffusion
High Concentration
Low Concentration
Cell Membrane
Glucosemolecules
Proteinchannel
Through a Protein channel without needing ENERGY
Channel Proteins animations
Facilitated Diffusion
To a-
From a- High
Low
Diffusion
Facilitated diffusion
(Channel Protein)
H2O
ions
Diffusion (Lipid Bilayer)
O2
CO2
Active TransportMovement across the cell membrane that
requires energy
high
low
This is gonna be
hard work!!
Actively moves molecules to where they are needed
Active TransportDefinition: The movement of material against the concentration gradient.
From an area of low concentration to an area of high concentration
3 Different types:
1. Protein Pump
2. EndocytosisA. PinocytosisB. PhagocytosisC. Receptor-mediated Phagocytosis
3. Exocytosis
Active Transport
Transport Proteins:
move ions against the force of diffusion
Protein Pumps
Show video clip
To do this…Protein changes shape to move the molecules.
Protein Pumps
Show video clip
THIS REQUIRES ENERGY!!!
Protein Pumps
How Does This Happen? Material binds to protein Mitochondria provides
energy that changes the shape of the protein
Change in shape allows material to be moved across membrane
System resets
Protein Pumps
Pumps are used to make neurons work, and for muscle movement
Ex: sodium / potassium pump:
important in nerve responses.
Sodium Potassium Pumps (Active Transport using proteins)
Used for…
1. large molecules
2. clumps of food
3. large amounts of liquid
4. whole cells
Uses energy!(cell membrane folds in on itself)
Endocytosis
Three Types of Endocytosis:
1st Type of Endocytosis: Pinocytosis
A cell engulfs solutes or fluids
“cell drinking”
2nd Type of Endocytosis:
Phagocytosis
A cell engulfs solids/food particles
“cell eating”
Forms food vacuole & digests
This is how white blood cells eat bacteria!
Phagocytosis
Phagocytosis
3rd Type of Endocytosis: Receptor-mediated Phagocytosis
Receptors are
shape specific!
Endocytosisleads to
Exocytosis
ENdocytosis vs. EXocytosisENter EXit
Endocytosis
Exocytosis
membrane surrounding the material fuses with cell membrane
Cell changes shape –
requires energy
Endocytosis & Exocytosis
animations
ExocytosisForces large molecules out of cell
Through exocytosis, the cell…
Excretes wastes
Secretes insulin and other types of hormones into the blood.
Exocytosis
Exocytosis
Vesicle-mediated transport
Exocytosis
Terms to remember
• Semi-permeable (Selectively Permeable) Membrane• Concentration Gradient• Diffusion• Facilitated Diffusion• Active Transport• Protein Pump• Endocytosis• Phagocytosis• Pinocytosis• Receptor-mediated Phagocytosis• Exocytosis
• Membrane has pores or spaces that let small molecules pass right through.
*O2, CO2, (H2O)
• Molecules that are LARGE and/or have a charge (+/-) are blocked.
*Proteins/Na+Cl-/Na+P3-
• Protein pores can control movement of charged ions and larger (but not too large) molecules.
*H2O, Glucose, Amino acids,
Hormones
Summary Factors of Movement
Review General USES of Active Transport…
Protein Pumps: used to make neurons work, and for muscle movement
Endocytosis: White cells digesting bacteria and cell debris
Exocytosis: Secrete insulin and other types of hormones into the blood. Cells get rid of waste!
Key fact: ALL forms of
active transport require . . .
ENERGY!!!
Active Transport
• Animations of Active Transport & Passive Transport
Review of Cellular Transport
Brainpop