Cellular Processes Standard 7-2.4 Explain how cellular processes (respiration, photosynthesis, waste elimation, mitosis, and reporduction) are essential to the survival of an organism.

Diffusion One way materials move across the cellular membrane Materials move from area of higher concentration to area of lower concentration

WHAT DOES THAT MEAN?

Molecules like their own space. If there are too many in one space then molecules will move to a place with less stuff (less molecules). DOES NOT NEED ENERGY TO MOVE! SPREAD OUT HIGH CONCENTRATION

Molecules move in and out of the cell through the cell membrane

Osmosis diffusion of water across the cellular membrane

What are the consequences to a cell if too much water goes…? INTO THE CELL OUT OF THE CELL SHRINKS BLOATS

NEEDS ENERGY to “move” substances across the membrane ACTIVE TRANSPORT NEEDS ENERGY to “move” substances across the membrane USUALLY MOVES SUBSTANCES FROM A LOW CONCENTRATION TO A HIGH CONCENTRATION

Active transport requires cell energy. Diffusion does not.

Active transport: Endocytosis: Cell membrane surrounds a substance and engulfs it Exocytosis: Vesicle with waste fuses with a cell membrane and then releases waste outside of cell(reversal of endocytosis)

PHOTOSYNTHESIS Plants use light energy (sunlight) to combine carbon dioxide and water to make simple sugars (glucose) Once the sugars are formed, they are either used by the plant or stored in the vacuoles. Photosynthesis occurs in the chloroplasts. Plant cells also release oxygen gas.

RESPIRATION Cells break down simple sugars into carbon dioxide and water and release energy. cell uses the energy to build, repair, and reproduce cells. Respiration occurs in the mitochondria of cells.

WASTE ELIMINATION Organisms rid the cells of waste products that could be harmful to the cell. As waste particles accumulate in a cell, the waste will move out of the cell and be eliminated.

The total of ALL chemical reactions in an organism Metabolism The total of ALL chemical reactions in an organism Enzymes Molecules that act as catalysts for cell processes (chemical reactions)

MITOSIS cell reproduction; process of cell division, occurs in the nucleus of the cell enables a cell to make an exact copy of it needed for growth, replacement, and asexual reproduction Results: production of two daughter cells from a single parent cell. daughter cells are identical to one another and to the original parent cell Video under MITOSIS- right click to view