Presentation Transcript
Chapter 3: Section 3 :Chapter 3: Section 3 Energy for Life
Moving Cell Materials :Moving Cell Materials A. Cells have a selectively permeable membrane that lets things in and out of the cell.
Passive Transport :Passive Transport The movement of substances through a cell membrane without the use of energy.
Examples: Diffusion – movement of molecules from where there is more to where there is less.
Osmosis – movement of water from where there is more to where there is less
Slide 4:The solutes will move to the left while water will move to the right; both are trying to reach equilibrium.
Active Transport :Active Transport Requires energy to move a substance through a cell membrane.
Examples:
Endocytosis brings food in.
Excytosis takes wastes
out.
Cells and Energy :Cells and Energy A. Metabolism – the total of all chemical reactions in an organism.
Cells use chemical reactions to release energy from food.
Most reactions need enzymes to speed things up.
Slide 8:B. Photosynthesis- the process that plants and other organisms use to convert light energy into chemical energy or sugars to be used as food.
During photosynthesis, producers use light energy to make sugars, which can be used as food.
Slide 10:Producers – organisms that make their own food.
Examples: Plants
Consumers – organisms that can’t make their own food.
Examples: Animals
Slide 11:2. Chlorophyll and other pigments are used in photosynthesis to capture light energy which is used to produce sugar and oxygen.
Bonus:
Carbon dioxide + water + sunlight =
oxygen and sugar (energy)
Slide 12:C. Cell Respiration – the process in which chemical reactions break down food molecules into simpler substances and release stored energy
Slide 13:1. Breaking down of carbohydrates (sugars from food) begin in the cytoplasm and finish in the mitochondria.
2. In the mitochondria the sugars are broken down again, releasing much more energy and used to make the body run
3. This process uses oxygen and produces carbon dioxide and water as wastes.
Slide 15:E. Photosynthesis and respiration – almost the opposite of each other!
Photosynthesis produces sugars and oxygen, which are used in cell respiration.
Respiration produces carbon dioxide and water, which is used in photosynthesis.