Homeostasis and Transport

Passive Transport Molecules moving from a high to a low concentration; NO ENERGY REQUIRED

How Diffusion Works

Another Example of Diffusion

Examples Sugar dissolving in water

Examples Demonstration in class

Examples Oxygen and carbon dioxide into and out of our lungs

Questions 1.What do the molecules move across? 2.What happens when the concentrations become equal on both sides? 3.What is this called?

Osmosis Passive Transport No energy needed Water molecules move from a high to a low concentration

Remember! Water moves to where there is more stuff! How Osmosis Works Osmosis Jones

Hypertonic Solution THINK-when you are HYPER in school, you have to LEAVE the room

Hypertonic

Hypertonic

Hypertonic

Hypotonic THINK-"hypo hippo" the cell gets big like a hippo :)

Hypotonic

Hypotonic

Isotonic….Iso means??? when concentrations of solutes inside and outside the cell are equal

Isotonic

Some unicellular freshwater organisms require a lower concentration of water in the cytoplasm to function normally. A paramecia will use a contractile vacuole to remove water, but this requires energy

Plants and Turgor Pressure?

The plant cells on the left have turgor pressure, the ones on the right do not.

Hmmm..which is which?

Facilitated Diffusion *Facilitate means to make easier, help *Another type of passive transport *No energy required

Molecules are too big to move across the membrane. hmmmm *Molecules are too big to move across the membrane. hmmmm *Transport proteins are used like channel proteins and carrier proteins

Facilitated Diffusion Animation

Active Transport: the movement of a substance against its concentration gradient

*low to high concentration *REQUIRES ENERGY

Sodium-Potassium Pump

Other Types of Transport Endocytosis: cell bringing in large molecules Other Types of Transport Endocytosis: cell bringing in large molecules Pinocytosis: cell drinking Phagocytosis: cell eating

Exocytosis: large substances exiting the cell

WHY ALL OF THIS? TO MAINTAIN HOMEOSTASIS!