1. Homeostasis and Cell Processes

2. Homeostasis
Balance
Cell wants to stay constant even when its environment is changing
Allows cells to carry out life processes such as getting energy, dividing, transporting materials
Cells in Multicellular organisms need each other to maintain homeostasis

3. How do cells get energy? Cells needs energy to perform cell functions
Energy comes from food
Plants make food then break the food down into energy
Plants, animals, and other organisms break down food for energy

4. photosynthesis Takes place in chloroplasts
Water + carbon dioxide + sunlight  sugar + oxygen

5. Cellular respiration Takes place in mitochondria
Uses oxygen to break down food to make atp energy
Sugar + oxygen  water + Carbon Dioxide + ATP

6. How do cells divide? Unicellular organisms reproduce by dividing
Multicellular organisms grow when cells divide
DNA is copied and split evenly
The nucleus splits (mitosis) to form two new nuclei
The rest of the cell splits for two new cells

7. How do cells exchange materials?
Materials enter and leave the cell through the membrane
Passive transport takes place without using energy
2 types of passive transport: diffusion and osmosis

8. Diffusion
Movement of particles from areas of high concentration to areas of low concentration

10. osmosis the diffusion of water through a semi- permeable membrane
Semi-permeable means only some substances can pass through
Fluids in and around cells are mostly water

12. Active transport
Takes place when cell need to move materials from low concentration to high concentration
Requires energy

13. Endocytosis vs. ExoCytosis
Copy the definitions and pictures from p in your textbook