Cells Capture and Release Energy Chapter 2.2C

Warm-up—COPY!!! The Sun provides much of the energy needed for ALL living things. How? Describe the difference between chlorophyll and chloroplasts. Where would a plant store energy? What is one of the main activities that take place in mitochondria? Does this happen in a plant or an animal cell? How do photosynthesis and cellular respiration “complement” each other? What are the two main types of fermentation and what are their products? Why do your muscles burn when you exercise?

All Cells Need Energy Plant cells—energy from sunlight Animal cells—energy from food Chemical energy—stored in bonds between atoms of every molecule Major source of energy is stored in a sugar molecule called glucose

Photosynthesis Plants change the energy absorbed from the sun into the chemical energy in glucose Chlorophyll (pigment found in chloroplasts) traps the energy in sunlight Carbon dioxide from air, water from soilenergy from sunlight changes CO2 and H2O into…glucose and oxygen (oxygen expelled as waste, glucose used for energy)

Glucose is used as well as stored Stored glucose links together to form a starch, which can later be broken back down to form glucose for energy

All Cells Release Energy When the bonds of a sugar molecule are broken down, energy is released that can be used by the cell Two basic processes: cellular respiration and fermentation

Cellular Respiration Takes place in mitochondria Sugars and oxygenglucose in cytoplasm is broken down releasing energy; after moving into the mitochondria, oxygen also enters in, combining with hydrogen to make waterenergy, carbon dioxide and water

Fermentation (Eukaryotic) Cells release energy without oxygen Two main types: alcoholic and lactic acid Products of alcoholic fermentation: Bread Products of lactic acid fermentation: Yogurt Cheese Sourdough bread

Exercise During prolonged exercise, your body uses all of its energy and oxygen, then relies on fermentation to break down sugars When your cells use fermentation, it can cause a burning sensation in your muscles After resting and breathing hard (taking in more oxygen), your muscles are able to finish releasing energy and store more energy to use for next time