Download CELL RESPIRATION

CELL RESPIRATION
Read chapter 9 in Campbell
Directions: For each term make a flash card with the definition on one side and the term on
the other side.
Key Terms: metabolism
anabolism
catabolism
reduction
oxidation
redox reactions
adenosine triphosphate (ATP)
adenosine diphosphate (ADP)
adenosine monophosphate (AMP) inorganic phosphate
anaerobic
glycolysis
coupled reactions
NAD
pyruvic acid
fermentation
lactic acid
ethanol
aerobic
cellular respiration
acetyl-CoA
Krebs citric acid cycle
FAD
chemiosmosis
electron-transport chain
chemiosmotic gradient
Q10
substrate level phosphorylation
oxidative phosphorylation
Answer the following questions:
1. Define oxidation and reduction in terms of gain and loss of electrons. Indicate whether
reducing a substance stores or releases energy in that substance and do the same for
oxidizing a substance.
2. Draw an ATP molecule; label the adenine and the ribose portions, and the parts
constituting adenosine monophosphate, adenosine diphosphate, and adenosine
triphosphate, respectively. Explain how ATP is formed from ADP and inorganic
phosphate, and state whether the reaction involved is exergonic or endergonic. Describe
the role ATP plays in the transfer of cellular energy.
3. Draw a diagram which points out and name the starting product and the end products of
glycolysis; point out the reactions in which phosphates from ATP are transferred to
glucose; point out the oxidation-reduction reaction, and point out the two reactions in
which molecules of ATP are synthesized. Summarize the ATP production of glycolysis,
specifying the number of ATP molecules used to start these reactions, the number of
ATP molecules synthesized, and the net gain.
4. Explain what is meant by coupled reactions, and describe how exergonic reactions can be
used to push or pull endergonic reactions in order to get them to proceed.
5. Explain why NAD must be regenerated from NADH in order for glycolysis to continue.
Next describe how NAD is regenerated in the absence of oxygen. Specify what the end
product of fermentation would be in your body cells in the absence of oxygen, and what
it would be in yeast cells.
6. Summarize in an equation the conversion of pyruvic acid into acetyl-CoA. Show how
two of the six carbon atoms in the original glucose molecule have been released as CO2.
Indicate whether or not this reaction is a redox reaction.
7. Draw a diagram of the Krebs Cycle which shows the reactions in which CO2 is produced,
specify how many CO2 are produced in each "turn" of the Krebs Cycle, and indicate how
many turns of the cycle are necessary to oxidize the four carbons remaining from the
original molecule of glucose; point out the redox reactions, and point out the reaction in
which ATP is produced.
8. Draw a diagram that traces the pathway the electrons follow as they move down the
electron-transport chain. Describe what is meant by a chemiosmotic gradient and
explain why this gradient is important. State the approximate number of ATP molecules
formed per molecule of glucose resulting from electron transport and chemiosmosis.
9. Sketch a mitochondrion, labeling the outer membrane, the inner membrane, the matrix,
and the intermembranal space. Indicate where in the mitochondrion the Krebs cycle
takes place, where the electron transport enzymes are located, where the concentration
of H+ would be highest, and where the concentration would be lowest.
10. Draw a diagram or table that summarizes the ATP yield from the complete breakdown
of glucose to carbon dioxide and water. Indicate how many net ATP are formed in
glycolysis, how many via the Krebs cycle, and how many are formed by chemiosmotic
synthesis (electron transport). Compare the number of ATP produced from the
metabolism of one glucose molecule under anaerobic conditions with the number
produced under aerobic conditions.
11. Draw a diagram of the "Metabolic Pathways", which shows how carbohydrates, fats and
proteins can be metabolized to yield energy in the form of ATP.