Biology Cell Respiration
Terms in this set (22)
If cellular respiration is a process that yields ATP molecules, do you think this is a catabolic or anabolic pathway? Support your answer.
Cellular respiration is catabolic. The process breaks down organic molecules to yield energy in the form of ATP.
What role do the molecules NAD+ and FAD play in the process of cellular respiration? Give the redox equations for both molecules.
NAD+ and FAD are electron carrier molecules that can transport high energy electrons from one area to another and release them in order to harness their energy. FAD + 2H+ + 2 e- ->FADH2
NAD+ + 2H+ + 2 e- -> NADH + H+
Why are electron acceptors necessary in order for NADH + H+ and FADH2 to release stored energy?
Electron acceptors are necessary to gather the electrons at the end of the energy harnessing process.
Is oxygen a good agent for reduction or oxidation processes? Why?
Because oxygen has a high affinity for electrons, it is a good oxidizing agent. This is related to the valence level of oxygen atoms.
Which molecule contains more energy: FAD or FADH2? Explain your response.
FADH2. The creation of FADH2 from FAD stores electrons in the molecule, which can be released later, yielding energy.
Is the conversion of FADH2 to FAD an example of oxidation or reduction? Why?
Oxidation. Reduction adds electrons, oxidation removes them.
Suppose you are experimenting in a lab with an organism that dies in the presence of oxygen. Considering metabolic pathways, how would you categorize this organism?
This organism is likely an obligate anaerobe.
Glycolysis is considered an anaerobic process. What information can you determine from this description?
Glycolysis may occur in the absence of oxygen.
What carbon compound is created as a result of glycolysis?
What three energy storing compounds are created through the citric acid cycle?
NADH, FADH2, ATP
What is the net gain of ATPs from the breakdown of one glucose molecule at the end of the citric acid cycle?
When oxygen is present, oxidative phosphorylation can yield 3 ATPs per NADH and 2 ATPs per FADH2. After the first three steps of cellular respiration, we have 10 NADH molecules and 2 FADH2 molecules. How many ATP molecules can these electron carriers yield?
When analyzing the process of cellular respiration, it may help to compare the process to volleyball, with the first three stages being the 'set,' and the final stage the 'spike.' Explain why this analogy makes sense.
Just as the 'set' doesn't yield any points in volleyball, the first three stages of cellular respiration does not yield a lot of ATP. However, the set allows the spike to occur, which does yield points. Likewise, the first three stages of cellular respiration allow the electron transport chain and oxidative phosphorylation to occur, which yields a large amount of ATP.
Why is the creation of a proton gradient, through the electron transport chain, essential for the ultimate goal of energy production through oxidative phosphorylation?
The proton gradient causes the protons to flow across the membrane due to the nature of diffusion, and in doing so, the energy is harnessed through ATP synthase. Without the gradient, the protons would not flow in a particular direction.
In what way is ATP synthase like a turnstile? What object would represent people in this analogy?
Just as people walk through a turnstile to enter a building, protons enter ATP synthase to cross the membrane. As ATP synthase turns, it phosphorylates a molecule of ATP from the energy released by the proton. Likewise, a turnstile uses the movement of a person to change the number on the meter as the person enters.
How are electron carriers NADH and FADH2 utilized in the electron transport chain process?
The electron carriers release their electrons into the electron transport chain, which harnesses the energy and uses it to pump protons across the membrane and create a gradient.
How do you think the oxidative phosphorylation process would be affected by the lack of an electron acceptor at the end of the ETC? For example, what would happen if all of the oxygen were consumed during the process of phosphorylation, but reduced electron carriers were still available?
The lack of an electron acceptor would halt the phosphorylation process. If the spent electrons were not removed from the conclusion of the chain, they would essentially create a 'traffic jam,' and the process would cease until the electrons were removed. Oxygen readily accepts the electrons, creating H2O and allowing the process to continue.
Why does the valence number of an atom of oxygen allow it to be a strong electron acceptor, enabling more copious energy production?
Oxygen has a valence number of 6, so it has a high affinity for two additional electrons in order to fill its outer shell and become more stable.
Why is the creation of a concentration gradient essential for the process of oxidative phosphorylation?
The concentration gradient will cause the protons to flow back into the cell, through the ATP synthase, which will use their movement to generate energy and phosphorylate ATP molecules.
How would a condition that caused the inability of the previous steps of cellular respiration to create NADH and FADH2 affect production of ATP through oxidative phosphorylation?
Oxidative phosphorylation would likely not occur. The electrons donated by NADH and FADH2 are necessary to pump the protons outside of the cell and create the concentration gradient.
Compare the process of oxidative phosphorylation to the synthesis or hydroelectric power through using a dam.
Creating a dam allows us to harness the power of water as it moves from an area of artificially created high concentration to an area of low concentration. In a similar way, oxidative phosphorylation harnesses energy through the movement of protons from an area of high concentration to an area of low concentration.
Considering anaerobic respiration, explain why primordial Earth had a higher concentration of CH4, H2, and N2S than our current atmosphere.
These three gases were created as byproducts of anaerobic respiration, as a result of combining with the electron acceptors that were available in the atmosphere at that time.
OTHER SETS BY THIS CREATOR
Latin Roots 12-15, mon, mand, cred, fid
Vocabulary--Omni, Flect, Ten, Mon
LATIN ROOTS: FRACT (FRAG), LATIN ROOTS: OMNI