Chemistry Assignment

CHM130IN, Capstone Project – Cellular Respiration Jones-Willy

Cellular Respiration

Review chapter 22 in your chemistry text.

The cells of our bodies require a continuous supply of energy just to stay alive. The direct source of that energy is a molecule called adenosine triphosphate (ATP). This molecule is essentially nucleotide (the nitrogenous base adenine, a ribose sugar, and a phosphate group) with two extra phosphate groups attached (Figure 22.3 p 786)

The phosphate groups are negatively charged creating a repulsion which creates potential energy that is stored in ATP.

When a phosphate group is transferred to another molecule from ATP (like to a reactant in a reaction), energy can be used to a move a muscle cell, or to transport protein in a cell membrane. This transfer of the phosphate group, is how energy can be used for activities of the cell. This converts ATP into ADP (adenosine diphosphate), which can later be converted back to ATP and used over and over.

1. Is the release of a phosphate from ATP to form ADP an endothermic or an exothermic reaction?

Explain. 2. Is the conversion of ADP back into ATP an endothermic or an exothermic reaction? Explain. 3. ATP is considered to be a high energy molecule. How is energy stored in this molecule? Because of our constant need for ATP, much of our daily efforts to stay alive are related to eating food, which supplies the energy needed to convert ADP back into high-energy ATP. We refer to this process as “cellular respiration” because we take in oxygen, and oxidize our food to supply this energy. Our digestive system hydrolyzes carbohydrates into glucose, which can be transported by the circulatory system and carried directly into cells. The reactions of cellular respiration involving glucose are very complex, but the overall reaction is a simple one that looks like this:

C6H12O6 + O2 → CO2 + H2O + 38 ATP 4. Balance the above equation. (Ignore the ATP for now.)

CHM130IN, Capstone Project – Cellular Respiration Jones-Willy

5. Which reactant in this reaction is oxidized, and which reactant is reduced? Explain. 6. Is the breakdown of glucose endothermic or exothermic? Explain. 7. The body can absorb up to 120 grams of carbohydrate per hour from the small intestine. If we

assume this is all in the form of glucose, how many moles of glucose have been absorbed? 8. If all of the 120g of glucose are converted within muscle cells to energy (ATP), how many grams

of H2O will be produced? How many grams of CO2 will be produced?

9. Figure 22.2 p 785 shows the typical animal cell. Explain where the metabolic reactions take place in the cell.

Read through section 22.3 p 788-792 10. Describe the components and functions of FAD, NAD

+ .

11. NADH and FADH2 transfer their electrons to molecules in the electron transport chain. When this

occurs, are NADH and FADH2 reduced or oxidized? Explain. 12. How does the electronegativity of an oxygen atom compare to the electronegativity of the other

molecules in the electron transport chain? 13. Why is oxygen so important in the process of cellular respiration? What will happen in the

process of cellular respiration if the body does not receive enough oxygen? 14. How do cyanide and carbon monoxide affect the electron

transport chain when the body is exposed to either of these toxins?

15. Read and summarize ”Chemistry Link to Health ATP energy and Ca

2+ needed to contract muscles” p 787

16. Explain the diagram about muscle fibers shown