Biology 1107 exam 3 (ch 9,10,12,13)
Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C6H1206) in aerobic cellular respiration?
60-64
Density-dependent inhibition is explained by which of the following?
B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing.
Which of the following statements describes the results of this reaction? C6H1206 + 602 -> 6 CO2 + 6 H20 + Energy
C6H1206 is oxidized and O2 is reduced.
During acrobic respiration, which of the following directly donates electrons to the electron transport chain at the lowest energy level?
FADH2
After which checkpoint is the cell first committed to continue the cell cycle through M?
G1
Which of the foligwing statements describes NAD+?
NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric acid cycle.
In addition to ATP, what are the end products of glycolysis?
NADH and pyruvate
At the M phase checkpoint, the complex allows for what to occur?
Separase enzyme cleaves cohesins and allows chromatids to separate.
All cell cycle checkpoints are similar in which way?
They activate or inactivate other proteins.
Why are carbohydrates and fats considered high energy foods?
They have a lot of electrons associated with hydrogen.
Why do neurons and some other specialized cells divide infrequently?
They have been shunted into G0.
Which of the following is true concerning cancer cells?
When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.
In cellular respiration, the energy for most ATP synthesis is supplied by:
a proton gradient across a membrane.
The oxygen consumed during cellular respiration is involved directly in which process or event?
accepting electrons at the end of the electron transport chain.
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 of pyruvate?
acctvi CoA
The primary role of oxygen in cellular respiration is to:
act as an acceptor for electrons and hydrogen, foring water.
The MPF protein complex turns itself off by
activating a process that destroys cyclin components.
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
catabolic pathways.
Inside an active mitochondrion, most electrons follow which pathway?
citric acid cycle -> NADH -* electron transport chain -> oxygen
Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called
cyclins.
Where does glycolysis take place in eukaryotic cells?
cytosol
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP?
energy released from movement of protons through AT synthase, down the electrochemical gradient
Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent?
glycolysis
A molecule that is phosphorylated:
has an increased chemical potential energy; it is primed to do cellular work.
Where is ATP synthase located in the mitochondrion?
inner membrane
During aerobic respiration, electrons travel downhill in which sequence?
loses electrons and loses potential energy.
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction:
loses electrons and loses potential energy.
Where are the proteins of the electron transport chain located?
mitochondrial inner membrane.
Carbon dioxide (COs) is released during which of the following stages of cellular respiration?
oxidation of pyruvate to acetyl CoA and the citric acid cycle
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes:
oxidized
When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a proton), the molecule becomes:
reduced.
The ATP made during glycolysis is generated by:
substrate-level phosphorvlation.
In glycolysis, for cach molecule of glucose oxidized to pyruvate:
two molecules of ATP are used and four molecules of ATP are produced
