Section 4:2 Cell Energy

I. From the Sun Photosynthesis- when plants, algae and some bacteria use carbon dioxide, water and sunlight to produce food. 6CO2 + 6H2O + sun = C6H12O6 + 6O2 carbon dioxide + water + sun = glucose + oxygen Takes place in chloroplast. Plants capture energy from the sun in the chloroplast. Change the carbon dioxide and water into food

C. Food is form of glucose. Glucose is a carbohydrate and can be stored D. Photosynthesis also produces oxygen

II. Getting Energy from Food Animal cells have different ways of getting energy from food Cellular respiration- uses oxygen to break down food Fermentation- gets energy without using oxygen

B. Cellular respiration respiration means breathing Breathing supplies oxygen for cellular respiration Breathing also removes carbon dioxide Most complex organisms obtain energy through cellular respiration

glucose + oxygen = carbon dioxide + water + ATP C. During cellular respiration, food is broken down into carbon dioxide, water and energy is released. C6H12O6 + 6O2 = 6CO2 + 6H2O + energy glucose + oxygen = carbon dioxide + water + ATP Energy is used to maintain body temperature Some energy is used to form ATP; fuels cell activities

Process of cellular respiration takes place in the cell membrane in prokaryotic cells In eukaryotic cells, C.R. takes place in the mitochondria

Light Energy ATP Cellular Respiration Mitochondrion Chloroplast Photosynthesis Light energy, carbon dioxide, and water are used to make glucose in chloroplasts. Oxygen is released. Light Energy ATP Cellular Respiration Oxygen and the energy in glucose are used to make ATP. ATP is a molecule that stores energy in a form that cells can use. ATP is produced by mitochondria. Carbon dioxide and water are also released. Cellular respiration occurs in both plant and animal cells. CO2 Mitochondrion Chloroplast

D. Connection between Photosynthesis and respiration Photosynthesis transform the sun’s energy into glucose Photosynthesis uses carbon dioxide to make glucose and release oxygen Respiration uses oxygen to break down glucose and release energy and carbon dioxide Each process makes materials that the other needs.

E. Fermentation When muscles can’t get enough oxygen from cellular respiration, they use fermentation. Types of fermentation Lactic Acid- fermentation in muscles creates a build up of lactic acid in muscles. Cause burning sensation This also happens in muscles of other animals, fungi and bacteria Fermentation also occurs in bacteria and yeast