 There are more than 120 elements-25 are needed for life  Water is needed for chemical reactions. About 2/3 of every cell is water  Many form the 4 basic molecules for life ◦ Carbohydrates-sugar and starch used for quick energy ◦ Lipids-fats, oils and waxes needed for stored energy ◦ Proteins- for the growth and repair of tissues and to fight infections ◦ Nucleic Acids-DNA and RNA that have instructions for everything-especially reproduction

a. All cells need energy. Chemical energy is stored in the bonds of molecules like glucose.  A process used by plants and other autotrophs to convert the energy of sunlight into sugars.  It requires sunlight, water, and carbon dioxide.  It occurs in the leaves of plants in organelles called chloroplasts.

6CO 2 + 6H 2 O + ENERGY C 6 H 12 O 6 + 6O 2 CARBON DIOXIDE WATER GLUCOSE OXYGEN

c. Cells Release energy in two ways 1.Cellular Respiration-cytoplasm and mitochondria converts glucose into energy, CO 2 and water 2.Fermentation-allows cells to release energy without oxygen a.Alcoholic fermentation- makes alcohol b.Lactic Acid fermentation- makes lactic acid; milk, cheese and sore muscles

C 6 H 12 O 6 + GLUCOSE 6O 2 OXYGEN 6CO 2 + CARBON DIOXIDE 6H 2 O + ENERGY WATER ATP *Photosynthesis and Cellular Respiration are opposite processes

a. Certain things MUST enter the cell for it to survive. This can occur in 2 major ways: 1. PASSIVE TRANSPORT -requires no energy 2. ACTIVE TRANSPORT-requires energy 7

1. Oxygen 2. Carbon dioxide 3. Water 8

9 Cell membrane Inside cell Outside cell

10 Cell membrane Inside cell Outside cell diffusion

11 Cell membrane Inside cell Outside cell EQUILIBRIUM

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13 High H 2 O potential Low solute concentration Low H 2 O potential High solute concentration

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 The movement from lower concentration to higher concentration  Active transport requires the use of energy  2 ways that materials are moved 1. Endocytosis -very large molecules are brought into the cell 2. Exocytosis-materials are moved out of the cell (usually wastes)

 Temperature  Size of materials  Surface area of a cell*  Volume* *The surface area can sometimes increase faster than the volume or the cell’s ability to hold materials so it stops growing  Cell Shape

1.Cells need four large molecules to function: Carbohydrates, lipids, proteins and nucleic acids. 2.2/3 of all cells are water 3.Cells capture energy through photosynthesis and release energy through cellular respiration and fermentation 4.Materials are moved from areas of high concentration to low concentration through passive transport that does not require energy. Diffusion and osmosis are examples. 5.In active transport, energy is required to move materials from areas of low concentration to high concentration. Endocytosis and exocytosis are examples 6.Things that affect transport are: shape, size, volume, surface area, material size and temperature