Cellular Respiration Active Learning Exercise
1) What is the function of cellular respiration? 2) Describe how is ATP produced by substrate-­‐level phosphorylation? 3) Describe how is ATP produced by chemiosmotic phosphorylation? 4) Glycolysis occurs in ______________ . (name the part of the cell) 5) How many ATP are produced and consumed during glycolysis? 6) How many NADH are produced by glycolysis? 7) During glycolysis, glucose is converted to _____ (how many?) ____________. (what?) 8) Tell how many carbon atoms are found in each of the two compounds that you named in the question above. 9) Explain why 2 pyruvates are formed from one glucose molecule instead of only one pyruvate. 10) Name the organelle where aerobic respiration occurs? 11) During aerobic respiration, carbon dioxide (CO2) is removed from each pyruvate and then coenzyme A is added. This forms ____________. 12) How many NADH molecules are produced for each acetyl CoA during the step described in the previous question? 13) For each molecule of glucose that begins cellular respiration, _____ molecules of acetyl CoA are produced. 14) During the Krebs cycle (also called the citric acid cycle), each acetyl CoA is broken down and the carbon is released as _______ (name the molecule). 15) The process listed in the step above produces _____ (how many) ATP, _____ (how many) NADH, and _____ (how many) FADH2 for each acetyl CoA. 16) For each molecule of glucose that enters cellular respiration, the number of ATP, NADH, and FADH2 produced by the Krebs cycle is _____, _____, and _____. The answer to this question can be found by multiplying your answers to question 15 by your answer to question 13. 17) For each molecule of glucose that enters cellular respiration, how many Carbon dioxide molecules (CO2) are produced? 18) In animals, what happens to the CO2`produced during cellular respiration? 19) Where does the electron transport system get the energy needed to pump hydrogen ions (protons) into the intermembrane space? 20) The final electron acceptor in cellular respiration is __________. 21) Each NADH produced during glycolysis contains enough energy to produce _____ (how many) ATP by chemiosmotic phosphorylation. 22) The ATP produced directly during glycolysis is done by __________ ___________ phosphorylation. (2 words) 23) Each NADH produced during the formation of acetyl CoA and during the Krebs cycle contains enough energy to produce _____ (how many) ATP. 24) If there were no oxygen, fermentation enables glycolysis to occur but not __________ respiration. As a result, a total of _____ (how many) ATP are produced for each molecule of glucose. 25) If there were no oxygen and if fermentation did not occur, the cell would run out of __________ and glycolysis would stop. 26) The purpose of the reactions of fermentation are therefore to replenish the supply of __________ so that glycolysis can continue and produce ATP. Answers: 1) Cellular respiration functions to produce ATP. ATP stores energy for the cell.
2) The energy to phosphorylate ADP comes from a high-energy molecule that contains a phosphate group. The reaction is catylized by an
enzyme. The phosphate bond is broken and the phosphate group is transferred to ADP to produce ATP.
3) In chemiosmotic phosphorylation, a concentration of hydrogen ions is used to produce ATP. Hydrogen ions flow from where they are more
concentrated on one side of a membrane through ATP synthase to where they are less concentrated on the other side of the membrane. The
energy stored within the pressure gradient is used to phosphorylate ADP.
4) Cytoplasm
5) 2 are consumed, 4 are produced. The net ATP production is therefore 2.
6) 2
7) 2 pyruvate
8) glucose has 6 carbon atoms. Pyruvate has 3 carbon atoms.
9) Two pyruvates are formed because one glucose has enough carbon atoms to produce 2 pyruvates. Glucose has 6 carbon atoms and each
pyruvate has 3 carbon atoms.
10) mitochondrion
11) Acetyl CoA
12) 1
13) 2
14) CO2
15) 1 ATP, 3 NADH, 1 FADH2
16) 2 ATP, 6 NADH, 2 FADH2
17) 6
18) It is exhaled when the animal breathes.
19) from NADH and FADH2
20) oxygen
21) 2 to 3 ATP
22) substrate-level phosphorylation
23) 3
24) aerobic, 2
25) NAD+`
26) NAD+