CHAPTER 9: CELLULAR RESPIRATIONSTUDY GUIDE

1. Draw and label the parts in a mitochondrion and show where the different reactions happen.

2. Write the chemical formula for cellular respiration in symbols and words.

C6H12O6+6O2 6CO2+6H2O+Energy (ATP)Glucose (food) + oxygen = carbon dioxide + water + energy

o How does this equation compare to the equation for photosynthesis?It is the opposite/reverse. The products and reactants are flipped.

3. Describe the steps of Glycolysis.- 6 carbon glucose molecule is broken in half forming 2 - 3 carbon molecules known

as pyruvic acid. This requires 2 ATP molecules of energy.- In order to form pyruvic acid, 2 NADH are formed by accepting electrons, and 4 ATP

molecules are formed in that process.

4. List the products of Glycolysis.2 ATP net total2 NADH2 Pyruvic acid molecules

5. Describe the steps of Alcoholic fermentation.- Glycolysis must occur first, producing 2ATP and 2 NADH.- If no oxygen is present, it then goes into alcoholic fermentation.- Pyruvic acid losses a Carbon to form carbon dioxide.- NADH donates its electrons now creating a 2Carbon molecule known as ethyl

alcohol.

6.

Describe the steps of Lactic acid fermentation.- Glycolysis must occur first, producing 2 ATP and 2 NADH.- If no oxygen is present, it then goes into lactic acid fermentation.- NADH donates its electrons now creating a lactic acid.

7.

Describe the steps of the Krebs cycle.8. Describe the steps of ETS.

9. Define the following molecules used in the pathways you learned about and where they are found: Glucose – used for glycolysis, gets broken into pyruvic acid.

pyruvic acid – came from glucose. If oxygen is present it will enter the krebs cycle. If no oxygen present it will enter fermentation.

acetyl-CoA – Pyruvic acid is broken into this during the krebs cycle, it is a 2Carbon molecule.

citric acid – formed when acetyl CoA joins with a 4Carbon molecule during the krebs cycle. It is a 6Carbon molecule that gets broken down during the cycle.

FAD+ - Accepts electrons during the krebs cycle, thus forming FADH2, which will be used in ETC.

FADH2 – Donates its electrons to ETC, recreating FAD+, which gets recycled back to the krebs cycle.

NAD+ - Accepts electrons during the krebs cycle, thus forming NADH, which will be used in ETC.

NADH – Donates its electrons to ETC, recreating NAD+, which gets recycled back to the krebs cycle.

CO2 - released as a waste product during the krebs cycle of aerobic respiration.

ATP – Energy that is produced during Glycolysis and aerobic respiration but not during fermentation.

ATP synthase – a protein pump in the ETC, pumps Hydrogen ions across the membrane to the matrix.

ETS – Transports electrons to produce ATP molecules, the most efficient process.

10. Which stages require oxygen and which ones do not?Fermentation does not require oxygenCellular respiration does require oxygen

o What does anaerobic and aerobic mean?Anaerobic means without oxygenAerobic mean with oxygen

11. Which molecule forms when glucose is broken in half? Pyruvic acid – there are two molecules total

o What happens to the carbons in glucose as they pass through cellular respiration?The carbons combine with oxygen molecules, since cellular respiration takes place in the presence of oxygen, and forms carbon dioxide molecules which are then exhaled or released from the body.

12. What happens to pyruvic acid if there is no oxygen present? It enters fermentation

13. What are the two kinds of fermentation?Lactic acid and alcoholic fermentation

o Give examples of where each of these is used?Lactic acid fermentation takes place in muscle cells and in bacteria (lactobacillus) which are found in dairy products.

Alcoholic fermentation takes place in bread and beer/wine making.

o Explain the difference between quick energy during exercise and long term exercise?

Quick EnergyFast, High Intensity Workouts - Weight Lift, SprintNot enough O2 Glycolysis & Lactic Acid Fermentation0-90 seconds activity

Long-Term EnergySteady, Low Intensity Workouts - Jog, walk, enduranceO2 available aerobic respiration> 90 seconds of activityGlycogen stores last ~15-20 minutes break down fats, etc.

14. What high energy electron carriers are used in respiration? NADH

o How are these different from the ones you learned about in photosynthesis?They do not have a phosphate molecule.

15. What happens to the NADH’s produced during glycolysis and the Krebs cycle?They donate their electrons and become NAD+ and then are recycled back to where they came from to accept electrons again and continue the pathways.

16. What is another name for the Krebs cycle? _Citric Acid cycle___________

o How is CO2 formed?As pyruvic acid and citric acid are broken down, they lose carbon molecules. The carbon molecules combine with the surrounding oxygen molecules (because CR takes place in the presence of oxygen) and form carbon dioxide which is released from the body when we exhale.

17. Which ion ends up in the intermembrane space during ETS?H+ ions

18. How does ATP synthase work to make ATP?ATP synthase takes the H+ from the intermembrane space of the mitochondria and

pumps them through the inner membrane and into the matrix. As this happens ADP joins with a phosphate and makes ATP. Thus creating 36 ATP during ETC.

19. What is the final electron acceptor at the end of ETS?Oxygen and it will create water as a product.