Part 1: How Materials Move In and Out of a Cell…
Diffusion Diffusion is the tendency for a substance to move from an area of greater concentration to an area of lesser concentration.
This process continues until the two areas have equal concentration of the substance.
Osmosis Osmosis is the movement of water across a cell membrane.
The process of osmosis as well as diffusion occur without the cell using any energy.
Active Transport Active transport occurs when the cell uses energy to transport materials across the cell membrane.
Food molecules are moved into the cell while waste molecules are moved out.
Part 2: Cells and Energy How do photosynthesis and cell respiration help a cell get energy?
Photosynthesis Photosynthesis is the process by which light energy is used to make food.
The chloroplasts in a plant cell use sunlight to change carbon dioxide + water to make sugar. The waste product of this process is oxygen.
Cell Respiration Cell Respiration is the process of using oxygen to release stored energy by breaking down sugar molecules.
The mitochondria in both plant and animal cells use oxygen to break down sugar. This produces carbon dioxide, water, and energy! As a result the waste product is carbon dioxide. This process is the reverse of photosynthesis.
Fermentation Fermentation occurs when there isn’t enough oxygen available. (Usually when you exercise hard.) During this process sugars are partially broken down for use as energy.
Fermentation causes your cells to produce a by product called lactic acid.
Part 3: Cell Division What are the five stages of cell division?
Stage 1: Prophase
Each chromosome makes a copy of itself.
Stage 2: Prometaphase
Chromosomes become shorter and thicker. The chromosome copies fasten together. The nuclear membrane breaks down.
Stage 3: Metaphase
The chromosome copies line up along the cell’s center.
Stage 4: Anaphase
The chromosome copies split apart and are pulled to opposite ends of the cell.
Stage 5: Cytokinesis
Chromosomes become hard to see. The cell splits, and new nuclear membranes form.
Part 4: Specialized Cells How do specialized cells work together?
Cell Differentiation Cell differentiation is the development of cells into different and specialized cell types
Some examples of specialized cells are:
Tissues Groups of specialized cells that work together.
Some examples of tissue are brain tissue, nerve tissue, and muscle tissue.
Organ An organ is a group of tissues that function together to do a specific job
A couple examples of organs are the heart and the skin.
Organ System An organ system is a group of organs that work together to do a job
An example of an organ system is your digestive system. This system includes such organs as the esophagus, the stomach, and the intestines.