ATP
1. In cells, the energy available in food is used to make an energy-rich compound called
Glycolysis
2. The first step in releasing the energy of glucose in the cell is known as
ATP Synthase
3. The process that releases energy from food in the presence of oxygen is
Polar Bear
4. Which organisms perform cellular respiration
2 ATP molecules
5. The net gain of energy from glycolysis is
Anaerobic
6. Because fermentation takes place in the absence of oxygen, it is said to be
mitochondrion
7. The Krebs cycle takes place within the
Convert ADP to ATP
8. The electron transport chain uses the high-energy electrons from the Kerbs cycle to
cellular respiration
9. A total of 36 molecules of ATP are produced from 1 molecule of glucose as a result of
Oxygen Debt
10. During heavy exercise, the buildup of lactic acid in muscle cells results in
During glycolysis, glucose is bro- ken down into two molecules of pyruvic acid. The other products are ATP molecules and high-energy electrons that are picked up by NAD+.
12. How is glucose changed during glycolysis? What products are produced as a result of glycolysis?
After glycolysis, if oxygen is avail- able, a cell might carry out the rest of cellular respiration. If oxygen is not available, some cells carry out the rest of fermentation.
13. What are the two pathways that might follow glycolysis? What factor can determine which of those pathways a cell might follow?
6O2 + C6H12O6 → 6CO2 + 6H2O + energy; oxygen + glucose → carbon dioxide + water + energy
14. Use formulas to write a chemical equation for cellular respiration. Label the formulas with the names of the compounds
NAD+ picks up high-energy electrons produced during glycolysis, forming NADH. The large number of high- energy electrons quickly fills all of the cell’s available NAD+ molecules. Without NAD+, the cell cannot keep glycolysis going, and ATP production stops.
16. How is NAD+ involved in the products of glycolysis? What happens to a cell’s NAD+ when large numbers of high energy electrons are produced in a short time?
Pyruvic acid and NADH react together as NADH passes high- energy electrons to pyruvic acid
17. Which two compounds react during fermentation? Which of these compounds passes higher energy electrons to the other?
Lactic acid fermentation: glucose → lactic acid Alcoholic fermentation: glucose → alcohol CO2
Both have glucose as the reactant.
Both have glucose as the reactant.
18. Write the equations to show how lactic fermentation compares with alcoholic germentation. Which reactant(s) do they have in common?
Fermentation and cellular respiration are both processes that break down glucose and release the energy stored in the molecule. Both start with the process of glycolysis, which produces pyruvic acid. Cellular respiration requires oxygen as a reactant. Fermentation occurs with- out oxygen.
19. How are fermentation and cellular respiration similar? What is the main difference between their starting compounds?
During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of reactions that give off energy. The high-energy electrons that are produced are picked up by a series of electron carriers, and the energy is used to convert ADP into ATP.
20. Summarize what happens during the krebs cycle. What happens to the high energy electrons generated during the krebs cycle?
ATP synthase is a large protein through which hydrogen ions (H) pass, converting ADP into high- energy ATP.
21. How is ATP synthase involved in making energy available to the cell?
At the beginning of a race, runners’ energy comes from ATP that is present in their muscles and that is produced by lactic acid fermentation. When runners race for about 20 minutes, their bodies use cellular respiration to use stored carbohydrates to make ATP. The body stores energy in muscle and other tissues in the form of carbohydrate glycogen.
22. When runners race for about 20
minutes, how do their bodies obtain energy?
minutes, how do their bodies obtain energy?
…
• Cellular respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
…
• Glycolysis is the process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound
…
• Glycolysis captures two pairs of high-energy electrons with the carrier NAD+. Because glycolysis does not require oxygen, it supplies chemical energy to cells when oxygen is not available
…
• The two main types of fermentation are alcoholic fermentation and lactic acid fermentation
…
• In the absence of oxygen, yeast and a few other microorganisms use alcoholic fermentation, forming ethyl alcohol and carbon dioxide as wastes
…
• Animals cannot perform alcoholic fermentation, but some cells, such as human muscle cells, can convert glucose into lactic acid. This is called lactic acid fermentation
…
• During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
…
• The electron transport chain uses the high energy electrons from the Krebs cycle to convert ADP into ATP
…
• The products of photosynthesis are similar to the reactants of cellular respiration. The Products of cellular respiration are the reactants of photosynthesis
