Test 3- Respiration & Photosynthesis Flashcards
Which process precisely describes the cellular process of breaking down large molecules into smaller ones
Catabolism
Which of the following is (are) true for anabolic pathways?
They consume energy to build up polymers from monomers
Which of the following is a statement of the first law thermodynamics?
Energy cannot be created or destroyed
Which of the following is an example of potential rather than Kinetic Energy?
A molecule of glucose
The active site of an enzyme is the region that
Is involved in the catalytic reaction of the enzyme
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction
Loses electrons and loses potential energy
When electrons move closer to a more electronegative atom, what happens?
The more electronegative atom is reduced, and energy is released
Why does oxidation of organic compounds by molecular oxygen to produce CO2 and water release free energy?
Electrons are being moved from atoms that have a lower affinity for electrons (such as C) to atoms with a higher affinity for electrons (such as O)
Which of the following statements describes NAD+?
NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle
Where does glycolysis take place in eukaryotic cells?
Cytosol
The ATP made during glycolysis is generated by
Substrate level phosphorylation
The oxygen consumed during cellular respiration is involved directly in which process or event?
Accepting electrons at the end of the electric transport chain
Which process in eukaryotic cells will proceed normally weather oxygen (O2) is present or absent?
Glycolysis
Substrate-level phosphorylation accounts for approximately what percent of ATP formed by the reactions of glycolysis?
100%
During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, most of potential energy containing glucose is
Retained in the two pyruvates
In addition to ATP, what are the end products of glycolysis?
NADH and pyruvate
Starting with one molecule of glucose, the energy-containing products of glycolysis are
2 NADH, 2 pyruvate, and 2 ATP
A molecule that is phosphorylated
Has an increased chemical potential energy; it is primed to do cellular work
Why is glycolysis described as having an investment phase and a payoff phase?
It uses stored ATP and then forms a net increase in ATP
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule pyruvate?
Acetyl CoA
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate?
2
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
Oxidation of pyruvate to acetyl CoA and the citric acid cycle
The primary role of oxygen in cellular respiration is to
Act as an accepter for electrons and hydrogen? forming water
Inside an active mitochondrion, most electrons follow which pathway?
Citric acid cycle –> NADH –> electron transfer chain –> oxygen
In chemiosmosis, what is the most direct source of energy that is used to convert ADP+Pi to ATP?
Energy released from movement of proteins through ATP synthase, down their electrochemical gradient
Where is ATP synthesis located in the mitochondrion?
Inner membrane
How many oxygen molecules (O2) are required each time a molecule from glucose is completely oxidized to carbon dioxide and water via anaerobic respiration?
6
Which of the following produces the most ATP when glucose is completely oxidized to carbon dioxide and water?
Oxidative phosphorylation (chemiosmosis)
Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose in aerobic cellular respiration?
60-64
Which of the following normally occurs regardless of whether or not oxygen is present?
Glycolysis
The ATP made during fermentation is generated by which of the following?
Substrate-level phosphorylation
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of
ATP, CO2, and ethanol (ethyl alcohol)
If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O) later analysis will show that all the following modules produced by the algae contain 18O except
02
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
ATP and NADPH
What oxygen is released as a result of photosynthesis, it is a direct by-product of
Splitting water molecules
A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?
Blue and violet
In the thylakoid membranes, what is the main role of the pigment molecule in a light harvesting complex?
Transfer light energy to the Reaction-center chlorophyll
Which of the events listed below occurs in the light reactions of photosynthesis?
Light is absorbed and funneled to reaction-center chlorophyll a
Which of the following are directly associated with photosystem 1?
Receiving electrons from the thylakoid membrane electron transport chain
Which of the following statements best describes the relationship between photosynthesis and respiration?
Photosynthesis stores energy in complex organic molecules whereas respiration releases it
In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during
Both photosynthesis and respiration
Reduction of oxygen to form water occurs during
Respiration only
What is the primary function of the Calvin cycle?
Synthesize simple sugars from carbon dioxide
