Mastering Biology #4 Flashcards
Why is glycolysis described as having an investment phase and a payoff phase?
It shifts molecules from cytosol to mitochondrion.
It both splits molecules and assembles molecules.
It uses glucose and generates pyruvate.
It attaches and detaches phosphate groups.
It uses stored ATP and then forms a net increase in ATP.
It uses stored ATP and then forms a net increase in ATP.
Within the mitochondria, oxidative phophorylation alone has a maximum, theoretical capacity to make 28 ATP per glucose. Why is it likely that the actual yield ot ATP will be less? Part complete
The proton gradient could be used for drive process other than ATP synthesis.
Intermediates in the TCA cycle may be siphoned off for other pathways.
Some mitochondria only ferment glucose.
A and B are correct.
A and B are correct.
If I add a poison that specifically blocks the mitochondrial electron transport chain, what is likely to happen to the activity of the TCA/Citric Acid Cycle?
Part complete
There will be no change because the two are not connected.
It will go faster to compensate for the reduced O2 consumption.
It will go faster to compensate for the higher amounts of pyruvate in the mitochondria.
It will go slower because NAD+ becomes limiting.
It will go slower because NAD+ becomes limiting.
In cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. What is the advantage of such an electron transport chain?
View Available Hint(s)
The electrons moving in the electron transport chain charge the chain with energy that is used to drive ATP synthesis.
The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates.
The advantage of the respiratory electron transport chain is that oxygen is the final electron acceptor.
The advantage of an electron transport chain is the production of a large number of reduced, high-energy intermediates.
The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates.
Explanation:
As the electrons “fall” down the electron transport chain, the energy released is used to actively transport protons into the inner-membrane space. This way the energy is used effectively, and not lost in the process.
Part A - Which best describes the Chemiosmotic principle for ATP synthesis?Part complete
Coupling the exergonic reaction of organic carbon oxidation with the reduction of ADP to ATP.
The transfer of Phosphate from a high energy organic molecule directly to ADP to form ATP in an exergonic reaction.
Use of the different concentrations of water across a membrane to drive enzymatic reactions in the matrix of the mitochondria.
The movement of ions with its electrochemical gradient across a membrane to drive the reaction of ADP and Pi.
The movement of ions with its electrochemical gradient across a membrane to drive the reaction of ADP and Pi.
An individual on a 6 month exercise and calorie restriction program managed to lose 3 Kg. Where did the 3 Kg go?Part complete
Mostly converted to heat and lost to the environment.
Mostly excreted as sweat.
Mostly lost as CO2 and water.
Mostly lost in feces and urine.
Mostly lost as CO2 and water.
How will a healthy individual’s ATP production change during an eight-hour fast?
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The energy levels will drop significantly, and weakness will follow due to decrease in cellular respiration.
The individual’s ATP production will decrease significantly.
The individual’s ATP production will increase significantly.
The individual’s ATP production will not change significantly.
The individual’s ATP production will not change significantly.
Explanation:
Catabolism can harvest energy from fats in fatty tissue or from storage proteins or glycogen in the liver. As a result, glycolysis and cellular respiration continue to produce ATP during a fast.
Mitochondria have infoldings of the inner mitochondrial membrane called cristae. What is the maine role of the cristae in mitochondria?Part complete
They prevent the loss of ATP from the mitochondria so that the ATP remains where it is needed.
They are due to the negative pressure caused by the proton gradient.
They increase the surface area to allow more respiratory protein complexes to be inserted.
They are due to the formation of water by the electron transport chain.
They increase the surface area to allow more respiratory protein complexes to be inserted.
Glycolysis is the oxidation of glucose to make a little ATP, a little NADH, and pyruvate. What other roles does this universal pathway have?
Catabolism of fats and lipids.
Catabolism of proteins.
Synthesis of amino acids.
All of the above.
All of the above
Part complete
What is meant by the “investment” and “payoff” phases of glycolysis?
stored ATP is required initially, but you generate more ATP by the end.
Phosphate groups are invested intially, and are lost by the end of the pathway.
NADH is used initially to make ATP by the end of the pathway.
You invest glucose into the pathway and get back pyruvate.
stored ATP is required initially, but you generate more ATP by the end.
What would happen to the mitochondrial electron transport chain during an oxygen deficit?
There would be no change.
Glycolysis would shut down.
The rate of the TCA cycle would increase to compensate.
The proton gradient would dissipate (disperse).
The proton gradient would dissipate
Most of the ATP synthesized via cellular respiration is produced by…
transferring a phosphate directly from pyruvate to ADP in the mitochondria of cells.
the oxidation of glucose to pyruvate.
substrate-level phosphorylation.
a proton gradient across a membrane driving an ATP synthase enzyme.
A proton gradient across a membrane driving an ATP synthase reaction
Part complete
Select the correct statement about cellular respiration.
View Available Hint(s)
Cellular respiration only happens in cells that have access to oxygen.
Plants carry out cellular respiration only in organs such as roots that cannot carry out photosynthesis.
Animals carry out cellular respiration, whereas plants carry out only photosynthesis.
Cellular respiration and breathing differ in that cellular respiration is at the cellular level, whereas breathing is at the organismal level.
Cellular respiration and breathing differ in that cellular respiration is at the cellular level and ATP is produced, whereas breathing is at the organismal level and lungs are used to exchange gases.
Athletes of which olympic event would be the most dependent on creatine phosphate in their muscles for energy?Part complete
Speed skating (5000m)
Weightlifting
Marathon
Rowing (2000m)
Weightlifting
a facultative anaerobic organism like yeast (able to grow in the presence and absence of oxygen) is grown on a limited amount of glucose. Yeast can use fermentation and release the watse product, ethanol, or grow in the presence of oxygen and oxidizing glucose via glycolysis and the TCA cycle. Under which conditions (Anaerobic or Aerobic) would you expect cells to grow faster and Why?
Anaerobic conditions — Faster conversion of energy in glucose to ATP.
They would have the same growth rate— They can efficiently use glucose under any condition.
Aerobic conditions — Higher yield of ATP from glucose oxidation.
Aerobic Conditions — Oxygen has more stored energy.
Aerobic conditions - higher yield of ATP from glucose oxidation.
