Cell+Processes

Cell Processes MITOSIS What it is:
 * A process of __cell division__
 * This is how cells make __more__ of themselves

Where it occurs:
 * This occurs in our body cells as well as in other animals and plants
 * "Mitosis takes place in my toes" (a way to remember it)

Uses:
 * Living things need to add more cells to __**GROW**__, which is done through mitosis
 * Mitosis creates new cells to __**REPAIR**__ wounds and other damages in the body
 * Mitosis __**REPLACES**__ dead cells
 * Mitosis is used for __**ASEXUAL REPRODUCTION**__
 * Asexual reproduction
 * Reproduction __without mating__
 * The offspring are exactly the same as each other and exactly the same as the parent
 * This is beneficial to make many offspring very quickly
 * Bacteria use this form of reproduction

Process of Mitosis:
 * One cell divides into __TWO__ new daughter cells **(Mitosis - T for two)**
 * The two new daughter cells are __exact copies__ of the parent cell
 * The two new daughter cells are exactly the same as each other **(Mitosis - T for Twins)**
 * Each new daughter cell is genetically identical to the parent cell

PHOTOSYNTHESIS [|Photosynthesis Webquest]

Plant cells cannot eat food, so they must make their own food. The process by which a plant cell makes its own food is called **photosynthesis**. First, photosynthesis cannot happen without light energy (usually from the sun). **Chloroplasts** found in plant cells have pigment chemicals called **chlorophyll**, which makes the plant green. Chlorophyll acts like the solar battery in a calculator - it stores sunlight energy for the plant to use during photosynthesis. Plant cells also need **carbon dioxide** for photosynthesis. Where does the carbon dioxide come from? It is a waste product from other living things. Finally, plants need **water** to make their own food. Plants absorb water through their roots. Inside the chloroplasts in plant cells, the carbon dioxide and water go through chemical reactions with the help of the energy from the sun. These chemical reactions produce two substances: **glucose**, a type of sugar, and **oxygen**. The plant can use the glucose right away, or it can be stored for later. When other organisms eat plants, they can use the glucose the plant had stored for their own energy!

Photosynthesis can be written as the equation:

water + carbon dioxide (in the presence of light energy) MAKES glucose + oxygen

Read A Change in Leaf Color by Emily Sohn.

CELLULAR RESPIRATION Now that the plant has made glucose, it needs to be able to use it. That's when cellular respiration happens. **Cellular respiration** is the process by which cells get energy from glucose. Cellular respiration happens in the **mitochondria** of both plant and animal cells. First, the **glucose** is broken into smaller pieces and moves into the cell. Next, **oxygen** moves into the cell. The glucose and oxygen head for the powerhouses of the cell, the mitochondria. Here glucose is broken down with the help of oxygen. When glucose is broken down, a great amount of **energy** is produced. The making of energy in cellular respiration makes some wastes, though. One of the wastes produced is **carbon dioxide**. This carbon dioxide is breathed out, or exhaled, by the organism. Another waste is **water**. Water can leave the body as a part of urine or sweat.

Cellular respiration can be written as the equation:

glucose + oxygen MAKES carbon dioxide + water + ENERGY

Comparing Photosynthesis and Respiration

During photosynthesis, plants use carbon dioxide and release oxygen. During respiration, organisms use oxygen and release carbon dioxide.

Photosynthesis and Respiration can be thought of as opposite processes. Together, these processes form a cycle that keeps the levels of oxygen and carbon dioxide constant in Earth's atmosphere.