Transport Chapter 5 How does stuff get in and out of a cell through the cell membrane?

How do molecules move? All molecules will move automatically from a region of ______ concentration to a region of ______concentration. _______________ HIGH LOW DIFFUSION

What if the HIGH and LOW places are on different sides of a cell membrane? Molecules will still go from HIGH to LOW if the cell membrane will let them through!

Some molecules can just pass right through the bilayer using DIFFUSION EXAMPLE: ___________________ oxygen, carbon dioxide

OSMOSIS When water molecules move across membrane from HIGH to LOW it is called ___________________ OSMOSIS

Cell Membrane Controls what enters & leaves the cell Only certain kinds of molecules can go across = ______________ SELECTIVELY PERMEABLE (Semi-permeable)

PROBLEM WITH CELLS What if a cell needs a molecule that can’t pass through the cell membrane easily?

Not all molecules can pass through easily

Need a way to move molecules across that can’t go by DIFFUSION ___________________________ Carrier Proteins Vesicles INTEGRAL PROTEINS that help molecules go across Small membrane sacs that carry molecules

2 KINDS of TRANSPORT ______________ TRANSPORT Does NOT require energy _____________ TRANSPORT Requires energy PASSIVE ACTIVE

VESICLES(vacuoles)

CARRIER PROTEINS PERIPHERAL INTEGRAL

FACILITATED DIFFUSION Image from:

FACILITATED DIFFUSION PASSIVE (No energy needed) HIGHER TO LOWER CARRIER PROTEINS GRAB & FLIP IT ACROSS EXAMPLE: _________________ GLUCOSE

ION CHANNEL Image from:

ION CHANNELS PASSIVE (No energy needed) HIGHER TO LOWER CARRIER PROTEINS MAKE A PASSAGEWAY Examples in cells : _______________________ Na +, Cl -, Ca + +, K +

PROBLEM WITH CELLS What if cell needs to move from LOW to HIGH? What if cell needs to move it fast and not wait? NEED TO ADD __________ IF YOU WANT A MOLECULE TO MOVE IN THE OPPOSITE DIRECTION IT NATURALLY GOES! ENERGY

What organelle supplies the energy?

Na + and K + PUMP Image from: e rg/ANIMTNS/Directry.htm

SODIUM-POTASSIUM PUMP ACTIVE (Uses energy) USES CARRIER PROTEIN Special just for Na + and K + ions Examples in cells: 3 Na + are pumped out of cells at same time 2 K + are taken into cells

VESICLES

ENDOCYTOSIS Brings substances into cell ACTIVE VESICLES CARRY MOLECULES INTO CELL –Fluid, molecules = Pinocytosis –large particles or whole cells = Phagocytosis Examples in cells: –one celled organisms eat this way –white blood cells destroy bacteria this way

Endocytosis

EXOCYTOSIS Substances are released outside of cell ACTIVE VESICLES CARRY & RELEASE MOLECULES Examples in cells: –GOLGI BODIES release packaged proteins

Exocytosis INSIDE CELLOUTSIDE CELL

Endocytosis & Exocytosis Outline2.gif/TransportMedia/EndoExocytosisMovie.htm

Diffusion Osmosis Facilitated Diffusion Ion Channels PASSIVE TRANSPORT

DIFFUSION WITHOUT a membrane PASSIVE HIGH TO LOW NO CARRIER PROTEINS NO VESICLES ANY MOLECULES BUT WATER

DIFFUSION ACROSS a membrane PASSIVE HIGH TO LOW NO CARRIER PROTEINS NO VESICLES ANY MOLECULES BUT WATER

OSMOSIS PASSIVE HIGH TO LOW NO CARRIER PROTEINS NO VESICLES FOR WATER MOLECULES

FACILITATED DIFFUSION PASSIVE HIGH TO LOW USES CARRIER PROTEINS Image from:

ION CHANNELS PASSIVE HIGH TO LOW NO VESICLES USES CARRIER PROTEINS FOR IONS Image from:

ACTIVE TRANSPORT Na+-K+ Pump Exocytosis Endocytosis Pinocytosis Phagocytosis

SODIUM-POTASSIUM PUMP ACTIVE USES CARRIER PROTEIN Special just for Na + and K + ions Image from:

EXOCYTOSIS & ENDOCYTOSIS ACTIVE (Need energy) USES VESICLES

Diffusion Osmosis Facilitated Diffusion Ion Channels PASSIVE TRANSPORT ACTIVE TRANSPORT Na+-K+ Pump Exocytosis Endocytosis Pinocytosis Phagocytosis

THE END

OSMOSIS Image from:

OSMOSIS ISOTONIC: Concentration outside cell ____________ concentration inside cell Water entering = water leaving so cell _____________________ EQUALS STAYS THE SAME SIZE

OSMOSIS HYPERTONIC: Concentration outside cell is ____________________ inside cell More water leaves cell than enters so cell shrinks ______________________ GREATER THAN = PLASMOLYSIS

OSMOSIS HYPOTONIC: Concentration outside cell is ________________ inside the cell More water enters than leaves cell so cell expands and can burst ___________________ LESS THAN = CYTOLYSIS

Animal cells

Plant cells

IS IT ISO, HYPO, HYPER? Named for LIQUID concentration NOT cell concentration

More solute OUTSIDE than inside cell HYPERTONIC Cell will shrink (PLASMOLYSIS)

LESS solute OUTSIDE than inside cell HYPOTONIC Cell will swell & burst (CYTOLYSIS)

EQUAL inside and outside ISOTONIC Cell stays the same size

Really THE END