CELL MEMBRANE CELL TRANSPORT CELL MEMBRANE Cell membrane

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CELL MEMBRANE & CELL TRANSPORT

CELL MEMBRANE & CELL TRANSPORT

CELL MEMBRANE Cell membrane vs. cell wall Cell Membrane All cells have cell membranes

CELL MEMBRANE Cell membrane vs. cell wall Cell Membrane All cells have cell membranes Flexible barrier Function: maintain homeostasis within the cell Cell Wall

CELL MEMBRANE STRUCTURE • Many names… cell membrane, plasma membrane, phospholipid bilayer • Phospholipid

CELL MEMBRANE STRUCTURE • Many names… cell membrane, plasma membrane, phospholipid bilayer • Phospholipid bilayer – two layers of phospholipids protein channel with Cell embedded proteins Layer 1 Membrane Layer 2 lipid bilayer protein pump

CELL MEMBRANE STRUCTURE Phosopholipid Bilayer Hydrophilic head – “water loving” attracts water Hydrophobic tail

CELL MEMBRANE STRUCTURE Phosopholipid Bilayer Hydrophilic head – “water loving” attracts water Hydrophobic tail – “water fearing” repels water Creates a constant push and pull

CELL MEMBRANE STRUCTURE Phosopholipid Bilayer Small materials can pass easily: 1. Push and pull

CELL MEMBRANE STRUCTURE Phosopholipid Bilayer Small materials can pass easily: 1. Push and pull of water 2. Porous nature 3. Vibrating phospholipids, creating openings

CELL MEMBRANE STRUCTURE “Fluid Mosaic Model”: explains the structure of the cell membrane Proteins

CELL MEMBRANE STRUCTURE “Fluid Mosaic Model”: explains the structure of the cell membrane Proteins and other embedded materials “float” within the cell membrane

CELL MEMBRANE STRUCTURE Carbohydrate Chain Cholester ol Phospholipi d Bilayer Transport/Channel Proteins Membrane Protein

CELL MEMBRANE STRUCTURE Carbohydrate Chain Cholester ol Phospholipi d Bilayer Transport/Channel Proteins Membrane Protein

CELL MEMBRANE FUNCTION - “Gatekeeper” - Semipermeable : Allows certain materials in and out

CELL MEMBRANE FUNCTION - “Gatekeeper” - Semipermeable : Allows certain materials in and out of the cell - Nutrients IN - Waste OUT - CELL TRANSPORT: MOVEMENT OF MATERIALS IN AND OUT OF CELLS

CELL TRANSPORT - The movement of materials in and out of cells (cell transport)

CELL TRANSPORT - The movement of materials in and out of cells (cell transport) … can be passive or active - Passive Transport: Does NOT require energy - Active Transport: Requires energy

CELL TRANSPORT Passive Transport - Does NOT require energy - Movement of materials from

CELL TRANSPORT Passive Transport - Does NOT require energy - Movement of materials from HIGH LOW - “with the concentration gradient” - Diffusion, Osmosis, Facilitated Diffusion

CELL TRANSPORT Active Transport - REQUIRES the use of energy - Movement of materials

CELL TRANSPORT Active Transport - REQUIRES the use of energy - Movement of materials from LOW HIGH - “against the concentration gradient” - Endocytosis and Exocytosis

PASSIVE TRANSPORT DIFFUSION Diffusion: movement of small particles from high to low until equilibrium

PASSIVE TRANSPORT DIFFUSION Diffusion: movement of small particles from high to low until equilibrium is reached

PASSIVE TRANSPORT DIFFUSION Diffusion: movement of small particles from high to low until equilibrium

PASSIVE TRANSPORT DIFFUSION Diffusion: movement of small particles from high to low until equilibrium is reached Particles are small enough to pass through the porous cell membrane

PASSIVE TRANSPORT - OSMOSIS Osmosis: the diffusion of water across a selectively permeable membrane

PASSIVE TRANSPORT - OSMOSIS Osmosis: the diffusion of water across a selectively permeable membrane Outside Cell Water will travel from HIGH concentration LOW concentration Inside Cell

PASSIVE TRANSPORT - OSMOSIS Osmosis: the diffusion of water across a membrane Water travels

PASSIVE TRANSPORT - OSMOSIS Osmosis: the diffusion of water across a membrane Water travels from high low Osmosis will take place until equilibrium is reached 25% sugar 75% water 60% sugar 40% water 50% sugar 50% water

PASSIVE TRANSPORT - OSMOSIS Osmosis: the diffusion of water across a membrane Water will

PASSIVE TRANSPORT - OSMOSIS Osmosis: the diffusion of water across a membrane Water will move in and out of cells when they are placed in various solutions

PASSIVE TRANSPORT - OSMOSIS Isotonic Solution – equal amount of solute in and out

PASSIVE TRANSPORT - OSMOSIS Isotonic Solution – equal amount of solute in and out of cell. Water moves in and out of cell in equal amounts Cell size does not change

PASSIVE TRANSPORT - OSMOSIS Hypertonic Solution – higher concentration of solute outside cell. Water

PASSIVE TRANSPORT - OSMOSIS Hypertonic Solution – higher concentration of solute outside cell. Water diffuses out of cell through osmosis. Cell shrinks/shrivels in size.

PASSIVE TRANSPORT - OSMOSIS Hypotonic Solution – higher concentration of solute inside cell. Water

PASSIVE TRANSPORT - OSMOSIS Hypotonic Solution – higher concentration of solute inside cell. Water diffuses into cell through osmosis. Cell expands and can even burst.

PASSIVE TRANSPORT – FACILITATED DIFFUSION Facilitated Diffusion – Diffusion of larger molecules which must

PASSIVE TRANSPORT – FACILITATED DIFFUSION Facilitated Diffusion – Diffusion of larger molecules which must be “helped” through the membrane by traveling through channel proteins & carrier proteins High Low! outside of cell No energy! inside of cell Glucose molecules

Outside cell Inside cell “bridge” squeezing motion

Outside cell Inside cell “bridge” squeezing motion

ACTIVE TRANSPORT REVIEW Active Transport - REQUIRES the use of energy - Movement of

ACTIVE TRANSPORT REVIEW Active Transport - REQUIRES the use of energy - Movement of materials from LOW HIGH - “against the concentration gradient” - Endocytosis and Exocytosis

ACTIVE TRANSPORT ENDOCYTOSIS Endocytosis – the movement of large molecules INTO the cell Low

ACTIVE TRANSPORT ENDOCYTOSIS Endocytosis – the movement of large molecules INTO the cell Low High Requires energy

ACTIVE TRANSPORT ENDOCYTOSIS Molecule “bumps” into cell membrane Cell membrane wraps around and engulfs

ACTIVE TRANSPORT ENDOCYTOSIS Molecule “bumps” into cell membrane Cell membrane wraps around and engulfs particle Creates a temporary vesicle/vacuole for transport

ACTIVE TRANSPORT ENDOCYTOSIS Examples: - Your white blood cells use energy to engulf bacteria

ACTIVE TRANSPORT ENDOCYTOSIS Examples: - Your white blood cells use energy to engulf bacteria - An amoeba bumps into something tasty!

A WHITE BLOOD CELL CHASING A BACTERIUM HTTPS: //WWW. YOUTUBE. COM/WATCH? V=JNL ULOJUHSQ

A WHITE BLOOD CELL CHASING A BACTERIUM HTTPS: //WWW. YOUTUBE. COM/WATCH? V=JNL ULOJUHSQ

ACTIVE TRANSPORT EXOCYTOSIS Exocytosis – the movement of large molecules OUT OF the cell

ACTIVE TRANSPORT EXOCYTOSIS Exocytosis – the movement of large molecules OUT OF the cell Low High Requires energy

ACTIVE TRANSPORT EXOCYTOSIS The golgi body plays a major role in the secretion (release)

ACTIVE TRANSPORT EXOCYTOSIS The golgi body plays a major role in the secretion (release) of proteins and other materials through exocytosis