Biology Exam 2
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon from one molecule of pyruvate?
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
it is lost to the environment
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?
Which of the following occurs in the cytosol of a eukaryotic cell?
glycolyis and fermentation
Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?
mitochondrial inter membrane space
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is most precisely described as
When you have a severe fever, what grave consequences may occur if the fever is not controlled?
change in the tertiary structure of your enzymes
An electron loses potential energy when it
shifts to a more electronegative atom
Which of the following statements describes the results of the reaction?
C6H120+6 O2=6CO2 +6 H2O+ energy
C6H12O6 is oxidized and O2 is reduced
Which of the following is an example of potential rather than kinetic energy?
a molecule of glucose
The active site of an enzyme is the region that
is involved in the catalytic reaction of the enzyme
How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
by changing the shape of the enzymes active site
According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?
the binding of the substrates changes the shape of the enzymes active site
Which of the following statement of the first law of thermodynamics?
energy cannot be created or destroyed
Why is glycolyis described as having an investment phase and a payoff phase?
it uses stored ATP and then forms a net increase in ATP
Which temperature and PH profile curves on the graphs were most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid?
Curves 1 & 4
In cellular respiration, the energy for most ATP synthesis is supplied by
a proton gradient across a membrane
A chemical reaction that has a positive G is correctly described as
the molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction
loses electrons and loses potential energy
which of the following terms best describes the forward reaction in figure 8.1?
The primary role of oxygen in cellular respiration is to
act as an acceptor for electrons and hydrogen, forming water
Where does glycolysis take place in eukaryotic cells?
Which of the following statements describes NAD+
NAD+ is reduced to NADH during glycolysis, pyruvate oxidation, and the citric cycle
Where is ATP synthase located in the mitochondrian
Where are the proteins of the electron transport chain located?
mitochondrial inner membrane
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
Which of the following is true for anabolic pathways?
they consume energy to build up polymers for monomers
Which curves on the graphs represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperature of 70 C or higher?
Curves 3 & 5
Which of the following statements is true concerning catabolic pathways?
the supply energy, primarily in the form of ATP, for the cell's work
Which of the following is true for exergonic reactions?
the reaction proceeds with a net release of free energy
Which of the following is an example of cooperativity?
a molecule binding at one unit of a tetramer, allowing faster binding at each of the other three
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as a reaction's:
why is ATP an important molecule in metabolism
it provides energy coupling between exergonic and endergonic reactions
For living organisms, which of the following is an important consequence of the first law of thermodynamics?
the organism ultimately must obtain all the necessary energy for life from its environment
in glycolysis, for each molecule of glucose oxidized its pyruvate
two molecules of ATP are used and four molecules of ATP are produced
How might an amino acid change at a site distance from the active site of the enzyme alter the enzyme's substrate specificity?
by changing the shape of the protein
Which of the following statements is a representative of the second law of thermodynamics?
cells require a constant input of energy to maintain their high level of organization
When skeletal muscle cells undergo anaerobic respiration, they become fatigued and painful. this is now known to be caused by
buildup of lactate
Which process in eukaryotic cells will proceed normally whether oxygen is present or absent?
Which of the following produces the most ATP when glucose is completely oxidized to carbon dioxide and water?
oxidative phosphoryilation (chemiosmosis)