27 terms

Bio 100 Ch.9 Mastering Biology

When ATP is hydrolyzed into ADP and inorganic phosphate, _____.
a large amount of energy is released
When one molecule gains an electron from another, the molecule that received the electron has been _____.
In cellular respiration, glucose is _____ and oxygen is _____.
oxidized, reduced
_____ is the three-carbon sugar that is produced as an end product of glycolysis.
How do allosteric regulation and competitive inhibition compare?
Competitive inhibition involves binding of a regulatory molecule to the active site; in allosteric regulation a regulatory molecule binds to a different location.
What molecule is produced in the citric acid cycle as a by-product of glucose oxidation and is subsequently released into the bloodstream and carried to the lungs, where it is removed from the body?
carbon dioxide
Why is ATP production during cellular respiration characterized as indirect?
ATP is not produced directly by the ETC but instead via the proton gradient generated during electron transport through the ETC.
What job does the electron transport chain accomplish in order to drive the formation of ATP?
The proteins in the electron transport chain pump protons from the matrix of the mitochondria to the intermembrane space, thus establishing an electrochemical gradient.
Which answer best explains why organisms that have an ETC as well as fermentation pathways almost never ferment pyruvate if the electron acceptor required by the ETC is available?
Fermentation is extremely inefficient in terms of the number of ATP molecules produced for each molecule of glucose metabolized
What purpose does fermentation serve?
It regenerates NAD+ from NADH to keep glycolysis going in the absence of oxygen.
Which term describes the degree to which an element attracts electrons?
Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?
Anion and cation
Which of the following statements is true of the bonds in a water molecule?
Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero.
Which of the following statements is not true of most cellular redox reactions?
A hydrogen atom is transferred to the atom that loses an electron.
A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?
Catabolic processes are activated that generate more ATP.
What kind of bond is formed when lithium and fluorine combine to form lithium fluoride?
Which of these is NOT a product of glycolysis?
n glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
How many NADH are produced by glycolysis?
In glycolysis, what starts the process of glucose oxidation?
In glycolysis there is a net gain of _____ ATP.
Which of these is an example of negative feedback?
After you eat, insulin stimulates the lowering of blood sugar levels.
Two ATP molecules are expended in the energy investment phase of glycolysis. Why is this energy needed to begin the process of glucose catabolism?
Some energy must be invested to make the glucose molecule unstable and begin the process of catabolism.
Canine phosphofructokinase (PFK) deficiency afflicts springer spaniels, affecting an estimated 10% of the breed. PFK is the glycolytic enzyme that phosphorylates fructose-1-phosphate and catalyzes the committed step in glycolysis. Given its critical role in glycolysis, one implication of the genetic defect resulting in PFK deficiency in dogs is _____.
an intolerance for exercise
Substrate-level phosphorylation occurs within a metabolic pathway where sufficient energy is released by a given chemical reaction to drive the synthesis of ATP from ADP and phosphate. In which of the following metabolic pathways is substrate-level phosphorylation exhibited?
in both glycolysis and the Krebs cycle
The reactions of pyruvate processing, the citric acid cycle, and the electron transport chain occur within the _____ in the cell.
Why is the citric acid cycle a cyclic pathway rather than a linear pathway?
It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA.