What do food molecules store?
Chemical energy
When do living things release that chemical energy?
When they break those food molecules down
What can energy in food be measured by?
Units called calories
What is a calorie?
The amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius
What is a kilocalorie?
1000 calories
Why does the amount of energy in different kinds of food vary?
Because of the differences in the way the atoms in food molecules are bonded together
What does the chemical energy help do?
It helps cells use the energy in foods to make compounds such as ATP
What do ATP and other useful energy compounds do?
Directly power the activities of the cell
Where do organisms get energy?
From food
What do living things get their energy from food through?
Cellular respiration
What is cellular respiration?
The process that releases energy from food, when there is oxygen present
What does cellular respiration give off?
Carbon dioxide, water, and energy
What is the cellular respiration process equation?
6o2+c6h12o6>>>6co2+6h2o+energy
True or false: a living cell has to release the chemical energy in food molecules a little bit at a time
True
What are the three stages of cellular respiration?
Glycolysis, the Krebs cycle, and the electron transport chain
Describe what happens when a sugar glucose goes through the three steps of cellular respiration
It enters glycolysis, some energy is used, the rest is locked in the bonds of a pyruvic acid. That acid then enters the Krebs cycle where a little more energy is given off. Then the last stage, the electron transport chain, uses oxygen and reactants from
What does aerobic mean?
In air
Which stages of cellular respiration are aerobic?
Krebs cycle and electron transport chain
What does anaerobic mean?
Without air
Which stage of cellular respiration is anaerobic?
glycolysis
Where does glycolysis take place?
cytoplasm of the cell
Where does the Krebs cycle and electron transport chain take place?
mitochondria
What happens when oxygen is not present in glycolysis?
Fermentation (another anaerobic path) keeps it running
Cellular respiration is balanced by _______
photosynthesis
What is the relationship between photosynthesis and cellular respiration?
Photosynthesis produces food molecules and removes carbon dioxide from the air, and cellular respiration puts it back. Photosynthesis gives off oxygen, and cellular respiration uses that oxygen to release energy from food