Cellular transport How are cells able to control what enters and what leaves the cell while maintaining homeostasis?

Two types of cellular transport Active Transport Passive Transport Cell uses energy Cell does not use energy

Passive transport Molecules move randomly Molecules move from areas of high concentration to low concentration Molecules move without use of energy

Types of passive transport Simple Diffusion Facilitated Diffusion Osmosis

Passive transport – 1. simple diffusion Random movement of particles from high concentration to low concentration Continues until equilibrium is reached Affected by: size of particles, concentration of particles, temperature

Passive transport – 2. facilitated diffusion Diffusion of larger molecules through transport proteins within the membrane -carrier or channel proteins -transport proteins are specific – they only allow certain molecules to pass through the membrane (EX: glucose, charged ions) Channel Protein Carrier Protein

Passive transport – 3. osmosis Special type of diffusion where water will move through a selectively permeable membrane Water moves from a high concentration to a low concentration

More about osmosis Three types of solutions Hypertonic Hypotonic Solute: the substance that is dissolved in a solvent (EX: sugar) Solvent: the substance the the solute is dissolved in (EX: water) Solution: solute + solvent Three types of solutions Hypertonic Hypotonic Isotonic

Hypertonic solution The solution has a higher concentration of solutes and a lower concentration of water than inside of the cell Water moves out Plasmolysis- cell shrinks

Hypotonic solution The solution has a lower concentration of solutes and a higher concentration of water than inside of the cell Cell takes in water *Animal cells will swell and burst (cytolysis)

TURN AND TALK TO A PARTNER An animal cell will swell and burst when placed into a hypotonic solution. When a plant cell is placed into a hypotonic solution, it will not. What prevents this from happening in the plant cell?

How Organisms Deal with Osmotic Pressure A paramecium pumps water out through a contractile vacuole Kidneys keep the blood isotonic by removing excess water. Paramecium (protist) removing excess water video

Vacuoles store water in a plant cell Osmotic (Turgor) pressure: pressure exerted by the movement of water during osmosis in a plant cell

isotonic solution The concentration of solutes in the solution is equal to the concentration of solutes inside of the cell Water moves in and out *Dynamic Equilibrium

Osmosis practice problems

Think-Pair-Share An IV is a direct infusion of liquid substances into a vein. Why would it be dangerous to give a person an IV infusion of distilled water? What about 90% salt solution?

Think Independently: In your spiral, write down what type of solution each cell was placed into: A: B: C:

Active transport Cell uses energy Molecules are actively moved to where they are needed Movement occurs from an area of low concentration to an area of high concentration

3 Types of active transport Protein Pumps Endocytosis Exocytosis

Active transport – 1. protein pumps Protein pumps: transport proteins that require energy to do work EX: Sodium/Potassium Pump The protein must change shape to move molecules across the membrane : requires energy

Active transport – 2. endocytosis Phagocytosis Taking particles into the cell Requires energy How the cell “eats”

Endocytosis- Amoebas eating lunch

Active transport – 2. endocytosis Pinocytosis Taking liquid into the cell Requires energy How the cell “drinks”

Active transport – 3. exocytosis Type of active transport where the cell transports molecules out of the cell Requires energy

DRAW a flow chart for cellular transport

CELLULAR TRANSPORT ACTIVE TRANSPORT PASSIVE TRANSPORT EXOCYTOSIS FACILITATED DIFFUSION PROTEIN PUMPS SIMPLE DIFFUSION OSMOSIS ENDOCYTOSIS PHAGOCYTOSIS PINOCYTOSIS