Essential Standard Bio.1.2 Analyze the cell as a living system. Cell Transport Essential Standard Bio.1.2 Analyze the cell as a living system.

Cell Transport Movement of materials across cell membrane 2 Types: Passive Transport Active Transport

Passive Transport Movement of substances across membrane without input of energy until equilibrium is reached With concentration gradient; high to low concentration 4 Types Diffusion Osmosis Facilitated Diffusion Ion Channels

Active Transport Movement of substances across membrane requiring input of energy Against concentration gradient; low to high concentration 3 Types Protein Pumps Endocytosis Exocytosis

Passive Transport - Diffusion Movement of molecules Molecules are in constant motion Moves “down” concentration gradient Rate of diffusion depends on Size of molecule Type of molecule

Passive Transport - Osmosis Diffusion of water Direction of osmosis depends on concentration of solutes on both sides of membrane Hypotonic solution Cytolysis Hypertonic solution Plasmolysis Isotonic solution

Osmosis Problems A cell which is 98% water is placed into a solution of 10% sucrose. What is the direction of the water movement?

Osmosis Problems A cell has 45% sodium concentration and is placed in a solution of 55% water concentration. What is the direction of the water movement?

Passive Transport – Facilitated Diffusion Diffusion of larger molecules Use carrier proteins (integral) No energy required

Passive Transport – Ion Channels Regulate flow of ions across membrane Ion-specific! Ions requiring ion channels: Na+, K+, Ca+, Cl-

Active Transport – Protein Pumps Carrier protein that transports molecules against concentration gradient

Active Transport - Endocytosis Large particles are engulfed into the cell Pinocytosis – “cell drinking” Phagocytosis – “cell eating”

Active Transport – Exocytosis Large particles exit the cell