The Cell in ActionChapter 2 Notes

Exchange with the Environment

• Diffusion- movement of particles from an area of high concentration to low concentration. • Osmosis is diffusion of water through a semipermeable membrane.• The cell wants to reach an equilibrium. A balance between the inside

of the cell and the outside of the cell..• These are known as passive transport, energy is not needed to

accomplish these tasks.

• Active transport requires the cell to use energy to move large particles into or out of the cell.• Endocytosis is when the cell brings large particles into the cell. Think

of the cell eating.• Exocytosis is when the cell is releasing large particles out of the cell.

As if the cell is going to the restroom.

Cell Energy

• Photosynthesis is the process that plants use to take energy from the sun, carbon dioxide and water to create glucose (sugar) and Oxygen.• Cellular respiration is a way that animals break down glucose into

water, carbon dioxide and energy.• Most cellular respiration takes place in the cell membrane.• Fermentation is a way that cells get their food from the cells without

using oxygen. Examples are when your body creates lactic acid after working out and your muscles cramp up.

The Cell Cycle

• Cell cycle is the life cycle of a cell. • DNA is made up of chromosomes.• Chromosomes are copied which ensures that the new cells have the

exact DNA as the parent cells.• Prokaryotic cells are less complicated and may split by binary fission.

The cell splits into two and each new cell has the matching DNA.

Cell Cycle cont.

• Homologous chromosomes are pairs of similar chromosomes.• Mitosis is the process in which a cell divides.• Phases of mitosis include: Interphase, Prophase, Metaphase,

Anaphase, Telophase and Cytokinesis. See Figure 4 on page 44 and 45. • In plants cells, a cell plate forms between the two new cells during

cytokinesis.