Cell Transport

Past learning: What is the function of the cell membrane?

Cyclosis: the streaming of cytoplasm

DIFFUSION The movement of molecules from an area of high concentration to an area of low concentration without using cell energy Examples: The smell of perfume through a room Sugar in coffee Food coloring in water

Diffusion high concentration low concentration

In which cell is diffusion occurring? B How do you know? Molecules are moving from high to low

In which direction will these molecules diffuse? high concentration low concentration

Why do molecules move from high concentration to low concentration?

All molecules are always in motion. Gas Solid Liquid The higher the temperature, the faster they move.

Brownian Motion Robert Brown observed particles inside of vacuoles vibrating. He stated that ALL particles are moving ALL the time.

Not to be confused with Brownie in Motion

Diffusion

Factors that affect Diffusion Concentration – greater concentrations results in more rapid diffusion Temperature: greater temperature results in greater speed of molecules

Facilitated Diffusion Molecules move rapidly across the cell membrane through a transport protein

Equilibrium Equilibrium is reached when molecules are evenly distributed

Equilibrium is reached. Into the cell or Out of the cell? Out of the cell. Into the cell. until... Equilibrium is reached.

Osmosis Diffusion of water through a membrane

Concentration Gradient The difference in concentration between an area of greater concentration and one of lesser concentration Diffusion occurs whenever there is a concentration gradient

Passive Transport Process by which materials move across the cell membrane without the expenditure of cellular energy Examples: Osmosis and Diffusion

Active Transport The process by which materials move across the cell membrane with the expenditure of cellular energy This allows the cell to be chemically different from it’s surroundings Moves molecules from low concentration to high concentration Examples: phagocytosis,pinocytosis and endocytosis

In which cell is active transport taking place? Cell A Is energy required? Yes!!!

Isotonic solution Contains the same concentration of dissolved substances as the cell placed in it

Hypotonic Solution Contains a lower concentration of dissolved substances than the cell Water is more concentrated outside Animal cells swell and burst Plant cells excess water is collcted inside the vacuole

Hypertonic Solution Has a higher concentration of dissolved substances than the cell Water is more concentrated on the inside Animal cells shrink Plant cells the vacuole will collapse and the cytoplasm will shrink

Iso hypo hyper