4.2 Respiration 7.1.d Students know that mitochondria liberate energy for the work that cells do and that chloroplasts capture sunlight energy for photosynthesis.

What is Respiration?  Respiration- the process but which cells obtain energy from glucose  Key Concept: “During respiration, cells break down simple food molecules such as sugar and release the energy they contain.  Cells of all living things carry out respiration because they need energy  Cells store energy like we store money in a bank- capture energy from sun and save during photosynthesis- when need energy the break down carbohydrates in respiration

Two Stages of Respiration  During respiration, cells break down simple food molecules such as sugar and release the energy they contain.

What is Respiration?  2 meanings for respiration- cellular respiration and breathing  Products of respiration-carbon dioxide and water  We breathe out carbon dioxide  Plants undergo Photosynthesis and make its own food (sugar)  Animal cells (and some others) get their glucose from eating plants or animals that ate plants  Respiration and Photosynthesis keep levels of oxygen constant on Earth  Respiration video Respiration video

What is Respiration?  Respiration equation:  Raw MaterialsProducts Video on Cellular respiration Yields Sugar Oxygen Carbon Dioxide Water

Photosynthesis and Respiration  You can think of photosynthesis and respiration as opposite processes.

The 2 Equations + energy

Fermentation  Fermentation- energy releasing process does not need oxygen  Key concept: “Fermentation provides energy for the cell without using oxygen.”  Amount of energy released is less than during respiration Mitochondria

Fermentation- Alcoholic  Type of fermentation when yeast and some other single celled organisms break down sugars  Called alcoholic because one of its products is alcohol  Other products are carbon dioxide and energy  Important to bakers- raises dough and creates bubbles in alcohol drinks

Fermentation- Lactic Acid  Takes place at times in your body  When running muscle cells use oxygen faster than it can replace it  Cells lack energy and fermentation occurs  Product is lactic acid  When the lactic acid builds up you feel pain (and weakness) in your muscles

What events occur during respiration? What is fermentation? Section 2: Respiration