bio ch 7
NAD+; NADH
One of the enzymatic results of the pyruvate oxidation stage of cellular respiration is the reduction of _____to _____.
mitochondrial matrix
The citric acid cycle takes place in the: Please choose the correct answer from the following choices, and then select the submit answer button.
These organisms likely carried out fermentation and may have had rudimentary proton pumps
Which statement is true regarding Earth's earliest organisms?
Pyruvate can be transported across both membranes of the mitochondrion to be further metabolized, but glucose cannot.
Which statement is true regarding pyruvate and glucose?
because these metabolic processes are found in nearly all organisms
Why do we believe that glycolysis and fermentation probably evolved very early in the history of life in an ancestor to essentially all life on Earth?
oxygen; glucose
A simplified overall equation for respiration is as follows: C6H12O6+ 6O2→6CO2+ 6H2O + energy In this reaction, we can say that _____is reduced and _____ is oxidized.
two molecules are used in the initial stage.
Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is because:
complex I, coenzyme Q, complex III, cytochrome c, complex IV, oxygen
An electron from NADH entering the electron transport chain would travel among components of the chain in what sequence?
two pyruvate molecules.
At the end of glycolysis, the carbon originally found in the starting glucose molecule is now present in:
intermembrane space; mitochondrial matrix
Due to the pumping action of the electron transport chain, protons have a high concentration in the _____and a low concentration in the _____.
electron carriers and ATP.
During glycolysis, pyruvate oxidation, and the citric acid cycle, the chemical energy in glucose is transferred to:
ATP is synthesized by substrate-level phosphorylation
During the citric acid cycle
oxidation; NADH
During the citric acid cycle, the production of CO2is the result of the _____of intermediate compounds of the citric acid cycle coupled to the production of _____.
during phase 3, when glyceraldehyde 3-phosphate is phosphorylated
During what phase of glycolysis is NADH formed?
payoff phase
During which phase(s) of glycolysis do we observe pyruvate production, ATP synthesis, and reduction of NAD+?
glycogen in animals.
Excess glucose is stored in large branched molecules of:
anaerobic.
Glycolysis is: Please choose the correct answer from the following choices, and then select the submit answer button.
traps glucose inside the cell
In addition to destabilizing glucose for subsequent breakdown, what else does phosphorylation of glucose do?
substrate-level phosphorylation.
In glycolysis, ATP is synthesized by:
pyruvate; NAD+
In pyruvate oxidation, the electron donor is _____and the electron acceptor is _____.
they are released as CO2 byproducts.
In the citric acid cycle, after the acetyl-group (2C) from acetyl-CoA is transferred to oxaloacetate (4C) to produce citrate (6C), subsequent reactions eventually result in 4C intermediates that are rearranged to regenerate oxaloacetate. What happens to the other two carbons?
a phosphorylated sugar molecule is broken apart and the products rearranged.
In the cleavage phase of glycolysis:
mitochondrion
In what organelle is pyruvate oxidation carried out in a cell?
Ethanol fermentation produces CO2 as a byproduct, but lactic acid fermentation does not.
Lactic acid and ethanol fermentation differ in that:
it links glycolysis with the citric acid cycle.
Pyruvate oxidation is an important stage in cellular respiration because:
CO2, FADH2, NADH, and ATP
Some bacteria run the citric acid cycle in reverse. Without any other modifications to the cycle, what inputs would be required to do this?
2; 3; 2; 2
Starting from glucose, lactic acid fermentation results in _____molecules of lactic acid, each with _____ carbons, whereas ethanol fermentation results in _____ molecules of ethanol, each with _____ carbons.
beta-oxidation.
The breakdown of fatty acids takes place by a process called:
many of these bonds are C—C and C—H bonds, in which electrons are shared equally between atoms
The chemical bonds of carbohydrates and lipids have high potential energy because:
NADH and FADH2.
The immediate source of electrons for the electron transport chain is:
oxidative phosphorylation
The mitochondrial electron transport chain is part of:
glycogen; starch
The storage carbohydrate in animals is ___________and in plants is __________.
Different sugars can be modified to form different intermediates of glycolysis.
We consume a variety of carbohydrates that are digested into a variety of different monosaccharides. How do these different sugars enter glycolysis?
Glucose is destabilized so that it can be broken apart in phase 2.
What happens when glucose is phosphorylated during phase 1 of glycolysis?
CO2
What is the fully oxidized product that results from the pyruvate oxidation stage of cellular respiration?
oxidized; reduced
When an electron is transferred from NADH to CoQ, NADH is _____and CoQ is _____.
from rotational energy provided by the flow of protons through the channel in the Fo subunit
Where does the F1subunit of ATP synthase get its energy to catalyze the synthesis of ATP?
glucose
Which of the following are inputs, but not outputs, of glycolysis?
reduction of acetaldehyde, derived from pyruvate
Which of the following describes the key reactions in fermenting beer, wine, or other alcoholic beverages?
water
Which of the following is a product (as opposed to a substrate) of at least one of the processes of cellular respiration?
NADH
Which of the following is an electron carrier in its reduced form?
It does not require oxygen
Which of the following is one explanation for why glycolysis is believed to have arisen very early in the evolution of life
It is an electrochemical gradient.
Which statement describes the proton gradient generated by the electron transport chain?