1. Unit 4: Cells and the internal environment
Journal 4-1 Notes

2. Levels of Organization in Biology
Small systems to Big systems

3. This Section deals with
Internal Cellular Environments
And
Homeostasis

4. Unit 4: Internal Environment
What the is the “Internal Environment”?
Your…
Cells
Tissues
organs
Cells - functional unit of life
Cells require certain internal conditions to function
What do we know about Enzyme activity to support this statement?

5. Maintaining a Balance
Homeostasis - maintaining a stable, constant internal environment
Organisms maintain constant internal levels of….
Water
Blood glucose
Oxygen in the blood
Electrolytes (sodium, potassium, etc…)
What will we study?
Cells and Molecular Movement
Body systems - circulatory, urinary

6. Digestive System (Review)
What is the purpose of ingesting food (eating)?
Small Intestine - location of absorption of nutrients.
Where do the nutrients go?
How does this happen?
Nutrients must move from the external environment to the internal environment.

7. Absorption in the Small Intestine
Diffusion - movement of molecules from an area of high concentration to an area of low concentration
Nutrients move into blood stream