Cellular Metabolism Lab

We will walk through the steps of Cellular Respiration in this activity. Please do not skip ahead or leave out steps. This assignment will help you to gain a deeper understanding of cellular respiration (the process of making energy, ATP, the major contributor to our overall metabolism). Pages 941-948 in you TEXTBOOK should help you answer the questions. This assignment is worth 72 pts total (each question is worth 1 point unless otherwise noted).

Instruction Notes: Complete this worksheet using one of the following ways (not both):

1) Print out this document and the metabolism shapes document. Cut out the metabolism shapes and then add your answers and images of shapes to the designated questions. Then scan or take a picture of each page and upload the entire document for grading.




2) Answer the questions on this template and copy/paste your images from the metabolism shapes document to the specified locations below. Images from any other source will not be accepted! Then save this document to your computer and upload the entire document for grading.

3) Before you begin, if you are printing this document, you will need to cut out all the shapes on the accompanying metabolism shapes document.

I. Glycolysis- The splitting of Glucose

1) Arrange individual carbons from the metabolism shapes document to form glucose- a six carbon molecules.

2) Now cut your glucose molecule into 2 pyruvate molecules.

3) Insert an image of your two pyruvate molecules here (Worth up to 2pts).

Answer the Following Questions after completing glycolysis:

4) Where does glycolysis occur? _________________________________

5) We began with glucose which is a ___ -carbon glucose molecule.

6) After ten separate reactions glucose is split into two ____________ molecules.

7) How many carbons does each molecule in question 6 contain? _____

8) The energy released during the breakdown of glucose causes two products to be made. The first product is two _______________ molecules which are which are used as reversible energy carriers.

9) The second product in question 8 is two _______________, which is usable energy for the cell.

10) Where do the 2 molecules of NADH that are produced in glycolysis go? ____________

11) Write out the final products of glycolysis. (3 points)


Glucose _____________ + ______________+ __________________


IIA. Anaerobic Respiration

12) This process requires _________ and NADH molecules from glycolysis.

13) In human cells, what is the product of anaerobic respiration? ______________

14) Using the metabolism shapes, insert the chemical equation for anaerobic respiration. Put reactants to the left of the arrow and products on the right. (Worth up to 3 pts)


Answer the following questions:

15) In the absence of oxygen, name the process that pyruvate goes through. ______________________ cellular respiration.

16) Where will this reaction occur in the ____________ of the cell?

17) What is the fate of lactate? Where does it go within the body? ____________


IIB. In the presence of Oxygen—Formation of Acetyl-Co A

18) In the presence of oxygen, pyruvate would instead go through ___________cellular respiration.

19) To create the chemical formula for the formation of acetyl-CoA, place your pyruvate plus co-enzyme A on the left side of the arrow. On the right you will put the products. Insert your formula here. (worth up to 3 points)

Answer these questions to help you determine those products.

20) This reaction occurs in ________________ of the cell?

21) Pyruvate bonds with __________________ to form acetyl co-enzyme A.

22) The excess carbon is bonded to oxygen to form two _______________ molecules (metabolic waste products).

23) The excess energy is stored in two ___________________ molecules (reversible energy carriers).

24) Acetyl Co-enzyme A can now enter the _________________ cycle.

What happens to each product of formation of Acetyl-co A? (Worth 1 pt each)

25) CO2- _________

26) NADH- _________

27) Acetyl Co-A- _________

III. Krebs Cycle (Citric Acid Cycle)

The acetyl-Co A is moved into the Krebs cycle, which consists of a series of chemical reactions.

28) What molecule does acetyl-Co A bind with at the beginning of the Krebs cycle? _________

29) What is the product of the reaction in question 28? _________

List the important products for one glucose molecule (2 rounds of Krebs Cycle) and their fate table below. *Hint: This is not asking for the intermediate molecules (i.e. isocitric acid, succinic acid, etc.). Look for products in the bubbles in figure 25.8 (pg. 947) in your textbook.

Table 1: Products of Krebs Cycle and their Fates. Worth 8 pts total.

Krebs Cycle Products (up to 4 pts) Fate of Each Product (up to 4 pts)
30) ______________

31) ______________

32) ______________

33) ______________

34) ______________

35) ______________

36) ______________

37) ______________

Answer the following questions about Krebs Cycle

38) Krebs Cycle occurs in __________________ of the cell.

39) Below, add an arrow to label the specific location in the organelle where the Krebs cycle occurs.

Related image

40) How are NADH and FADH2 used in the Krebs Cycle? ________________

41) Where do they go once formed? ______________________________

IV. Electron Transport Chain (Oxidative Phosphorylation)

The final reaction of aerobic respiration uses energy harvested elsewhere to generate ATP. Tally the NADH and FADHs that have come here from the previous aerobic steps on your electron transport chain sheet. Fill in the table below with your results. This will remind you of how many NADH and FADH2 molecules you should have and where they come from.

Glycolysis Intermediate Step Krebs Cycle
How many NADH came to the electron transport chain from Glycolysis?

42) _______


How many NADH came to the electron transport chain from the intermediate step?

43) _______


How many NADH and FADHs came to the electron transport chain from Krebs Cycle?

44) _______

45) _______


Table 2: The Sources of NADH and FADH2 in Aerobic Respiration

Building your Electron Transport Chain (ETC)

Use the diagram below to answer the following questions about the electron transport chain.


46) Label the mitochondrial matrix on the image above.

47) Where did the hydrogens (H+) in the matrix come from? _________

48) What else do NADH and FADH2 carry that gets transferred to the ETC proteins? *Hint: these provide energy to those proteins. _________

49) Label the inner membrane space on the image above.

50) Where did the hydrogens (H+) in the inner membrane space come from? _________

51) How did the hydrogens (H+) in the intermembrane space get there? _________

52) How do the number of hydrogens in the inner membrane space compare to the mitochondrial matrix? _________

53) Label ATP Synthase on the image above.

54) What is the function of ATP synthase? _________

55) Insert the reactants in the chemical equation to make ATP (worth 2 points).

________ + ________ ATP

56) How are the hydrogens (H+) from the inner membrane space involved in the action of ATP synthase? _________

57) The electron transport chain is located within the __________________ of the mitochondria.

58) Add an arrow to label this region on the mitochondria pictured below.

Related image

Finalizing the ETC reactions

59) Both the electron and the H+ that are now back in the matrix are “captured” when they are bonded to ________________ (last electron acceptor).

60) This process in question 59 forms _____________.


Summary of ATP/ Product Production

61) In anaerobic respiration, how many ATP molecules are produced? _____

62) In aerobic respiration, about how many ATP molecules are produced? _______. This sum is the total from each phase of cellular respiration.

How many ATP molecules come from each step of this process?

63) Glycolysis? ____

64) Citric Acid Cycle? ____

65) NADH and FADH2 molecules that pass through the ETC? ____

Note: The number of ATP molecules produced from each glucose molecule is theoretical because some tissues/ organs are more efficient like the liver, kidneys and heart. While other organs such as the brain and skeletal muscles are less efficient.

66) In addition to ATP, aerobic respiration produces ______ CO2 molecules.