Cell Processes The cell carries out a variety of processes necessary to life. Life processes performed by cells include: Metabolism Respiration Diffusion Osmosis Active Transport

Cells obtain energy from their environment and convert it into a usable form of energy. The energy conversion process is very complex and involves many chemical reactions. Metabolism is the chemical reactions involved in the building up and breaking down of nutrients in the cell. Metabolism

Respiration Respiration is the process by which simple food substances are broken down and the energy they contain is released. Respiration is performed constantly by living things. There are two types of respiration: Aerobic respiration which requires oxygen and makes ATP Anaerobic respiration or fermentation which does not use oxygen, but also does not produce as much energy.

Photosynthesis Plants have chloroplasts which contain a pigment called chlorophyll. Chlorophyll captures light energy and through chemical reactions it is changed to simple food molecules such as glucose. Carbon dioxide and water are needed for photosynthesis and oxygen and water are given off as waste products along with glucose.

Respiration & Photosynthesis Relationship

Diffusion The force behind the movement of many substance in and out of the cell is called diffusion. Diffusion is the process by which molecules of a substance move from areas of high concentration to areas of lower concentration. Diffusion works because particles are constantly in motion and flow to areas where they have more room to move. The organelles and cytoplasm do not diffuse out of the cell because the membrane is selectively permeable and does not let them pass through.

Osmosis Water is the most important substance that moves in and out of the cell. Water moves by a special process of diffusion called osmosis. Osmosis is the diffusion of water into or out of the cell and it keeps the cell from drying out. Osmosis and diffusion do not require energy

Substances that are not able to pass through the cell membrane by diffusion or osmosis are moved by the process of active transport. Active transport is a process that uses proteins and special molecules to move substance across the cell membrane. Active transport requires energy. Active transport is used for calcium, potassium, and sodium. Active Transport