Topics 18-25
Match the correct number of products produced when a single NADH delivers electrons to the electron transport chain. Number of oxygen (02) molecules produced.
0
Match the correct number of products produced when a single NADH delivers electrons to the electron transport chain. Number of water molecules produced.
1
Sort the stages of the Calvin cycle starting with the reaction catalyzed by rubisco.
1.Carbon fixation: CO2 is added to 5-carbon sugar. 2.Carbon reduction: high energy NADPH and ATP are used to reduce and add high energy bonds to carbon substrates. 3.Ribulose regeneration: 3-carbon glyceraldehyde-3 phosphates are used to regenerate 5-carbon ribulose bisphosphates.
Which of the following are contributing factors to the 'rubisco problem'?
1.When plants close stomata O2 accumulates in the cell 2.Excess O2 will be used by ribulose instead of CO2 and ribulose will be oxygenated instead of carboxylated. 3.Plants lose water when they exchange gases through open stomata
How many molecules of CO2 are formed by five turns of the citric acid cycle
10
Match the correct number of products produced when a single NADH delivers electrons to the electron transport chain. Total number of protons pumped from the matrix to the intermembrane space.
10
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis?
100%
For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced?
12
How many total ATP are produced from three glucose molecules through the various glycolytic pathways?
12
Match the correct number of products produced when a single NADH delivers electrons to the electron transport chain. Total number of electrons transferred.
2
Which of the following is generally accepted as the number of ATP produced for each NADH that contributes its electrons to the electron transport chain?
2.5 - 3
How many ribulose bisphosphates (RuBPs) must be fixed with CO2 to sustainably remove a single glyceraldeyde-3-phosphate from the Calvin cycle for the synthesis of glucose?
3
How many ribulose bisphosphates must be fixed with CO2 to sustainably remove a single glyceraldehyde-3-phosphate from the Calvin cycle for the synthesis of glucose?
3
Match the correct number of products produced when a single NADH delivers electrons to the electron transport chain. Maximal number of ATP produced.
3
Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle?
3 ATP, 6 CO2, 9 NADH, and 3 FADH2
How many reduced dinucleotides would be produced with four turns of the citric acid cycle?
4 FADH2 and 12 NADH
The jellyfish aequorea victoria contains a fluorescent protein that is optimally excited by 488nm wavelength light (a blue-green color). Based on your understanding of the second law of thermodynamics, which of the following describe the light emitted by this protein following excitation?
A green color with a wavelength above 488nm
Which of the following is not a product of the Calvin cycle?
ATP
Which of the following structures is directly involved in producing ATP in oxidative phosphorylation?
ATP synthase
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of
ATP, CO2, and ethanol (ethyl alcohol).
Which of the following is not a product of the citric acid cycle?
Acetyl-CoA
How does pyruvate enter the matrix of the mitochondrion?
Active transport
Which of the following conditions would favor pyruvate oxidation?
Aerobic
Which kind of metabolic poison would most directly interfere with glycolysis?
An agent that closely mimics the structure of glucose but is not metabolized
Pyruvate oxidation (to acetyl-CoA) cannot happen in the absence of oxygen. Which statement best describes the dependence of pyruvate oxidation on oxygen?
As the terminal electron acceptor, oxygen is required for the recycling of NADH back to NAD+.
You are motor biking on the St. Anthony sand dunes when you run across a previously unknown plant species. You bring a sample to the lab to study its regulation of photosynthesis. You inject radioactive malate into the leaf and find that there is a loss of malate during daytime when temperatures are high, but there is no loss of malate during the cooler nighttime temperatures. From this data you surmise that your plant is a new variety that uses the
CAM strategy
Caproic acid is a 6-carbon fatty acid (C6H12O2). When compared to glucose (C6H12O6), which molecule would generate the greatest amount of ATP production following the complete metabolism of each molecule?
Caproic acid
Which of the following is an example of potential energy?
Chemical bonds in glucose
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?
Competitive inhibition
Which portion of the ATP synthase complex has active sites for ATP and actually does the catalysis?
F1 region- β subunits
Which of the following describes the sequence of electron carriers in the electron transport chain, starting with the least electronegative?
FMN, Fe•S, ubiquinone, cytochromes (Cyt)
As a reaction proceeds toward equilibrium, its △G will eventually be positive.
False
Leafs are green because pigments in the chloroplasts absorb photons of light with wavelengths corresponding to the color green.
False
The △G of a reaction is always proportional to its energy of activation.
False
Which of the following contains the most potential energy?
Glucose
Which of the following is not a product of the light reactions?
Glucose
Which of the following processes is not involved in the metabolism of fatty acids?
Glycolysis
Which of the following colors of light is least effective in powering photosynthesis?
Green
Phosphofructokinase represents the key regulatory step of glycolysis. Which of the following statements are correct regarding the regulation of this enzyme?
High levels of phosphoenolpyruvate can inhibit this enzyme through a negative feedback loop.
Acidic amino acids within the enzyme will be deprotonated and negatively charged.
High pH
Basic amino acids within the enzyme will be deprotonated and have a neutral charge.
High pH
When a substrate binds to an enzyme, the enzyme usually changes shape, aiding in the catalytic process. What term is used to describe this change in shape?
Induced fit
What is the role of NAD+ in cellular respiration?
It is reduced as it accepts electrons from nutrient molecules.
Why is ATP an important molecule in metabolism?
It provides energy coupling between exergonic and endergonic reactions.
Which of the following is an example of an catabolic process? (Mark all that apply)
Krebs cycle Beta oxidation Protein digestion Glycolysis
Which of the following is not produced when pyruvate enters the mitochondria?
Lactate
In human muscle cells what are the end products of fermentation?
Lactate and NAD+
Acidic amino acids within the enzyme will be protonated and have a neutral charge.
Low pH
Basic amino acids within the enzyme will be protonated and positively charged.
Low pH
Which of the following best describes the roles of NADH and NADPH?
NADH is used in catabolic pathways and NADPH is used in anabolic pathways.
In which type of regulation does an inhibitor bind to a site that is not the active site on the enzyme?
Noncompetitive inhibition
Which of the following stages requires oxygen as reactant?
None of the above NOT: Ribulose regeneration stage Fixation stage Reductions stage
What is the final electron acceptor in the electron transport chain?
O2
Where would you find the electron acceptors of the electron transport chain?
On the inner mitochondrial membrane
Some people say that the energy currency abilities of ATP come primarily from its ability to easily transfer phosphate groups from its tri-phosphate tail to another substrate. What makes the phosphate groups of ATP so "anxious" to leave in favor of another substrate?
Phosphate groups contain multiple negative charges that repel each other.
On a hot day, a plant will close its stomata in order to
Prevent loss of water
Which of the following stages of the Calvin cycle require ATP?
Reducing stage and Ribulose regeneration stage NOT: Fixation Stage
Electrons will only travel through the electron transport chain in one direction. For example, from complex three to cytochrome c and not vice versa. Which of the following terms can be used to best explain this phenomenon?
Reduction Potential
Which of the following statements about rubisco are true?
Rubisco is able to use oxygen as a substrate. Rubisco is able to fix CO2 by carboxylating a 5 carbon sugar called ribulose. NOT TRUE: Rubisco regenerates ribulose from glyceraldehyde-3 phosphate Rubisco reduces CO2 using electrons from NADPH
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. Based on this information, which of the following is correct?
Succinate is the substrate, and fumarate is the product.
In order to attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur in order for the final attachment to occur?
The binding of the first two molecules must cause a 3-dimensional change that opens another active site on the enzyme.
According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?
The binding of the substrate changes the shape of the enzyme's active site.
Graph: Y axis: Gibbs Free Energy X axis: Reaction Progress Line starts on B, straight for a few cm, rolls up to A and down to C Using the reaction coordinate diagram above, fill in the blanks of the following sentences with the proper letters (A, B, or C):
The change in free energy (ΔG) is the difference between *C* and *B*. While the energy of activation is the difference between *A* and *B*.
Vitamin B3 is a precursor for NAD+. Back in the early 1900s, those living in orphanages and prisons were fed a corn-heavy diet. Absent the process of nixtamalization, vitamin B3 is poorly released from corn and individuals on this diet develop a condition called pellagra. Which of the following metabolic steps would be directly affected in those individuals with pellagra?
The conversion of pyruvate to acetyl-CoA
The process of oxidative phosphorylation can be likened to a battery that powers a water pump as well as a turbine which is powered by the pumped water. In this analogy, the proton motive force best can be represent by which of the following?
The force of the movement of the pumped water down through a turbine.
Some people say that the energy transfer abilities of ATP come primarily from its ability to easily transfer electrons from hydroxyl groups on its nitrogenous base to NAD+. What makes the hydroxyl groups so ready to donate electrons?
The nitrogenous base is not responsible for the energy transfer abilities of ATP.
For living organisms, which of the following is an important consequence of the first law of thermodynamics?
The organism ultimately must obtain all of the necessary energy for life from its environment.
Which statement best describes the primary purpose of fermentation?
The oxidation of NADH
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
The pH of the matrix increases.
ATP has three different structural regions. Which of the following regions is primarily responsible for the energy transfers that ATP carries out in the cell?
The poly phosphate
The reaction centers in photosystem I and II get their names from the wavelength of light that is optimally needed to excite their electrons. Which of the following statements is true then about these excitation wavelengths?
They have a lower energy level than most wavelengths of visible light.
Where would you find photosystem I?
Thylakoid membrane
What is the purpose of cyclic electron flow?
To produce enough ATP to power the Calvin cycle
Which of the following is true regarding the purposes of breathing?
To provide oxygen as a terminal electron acceptor
The earth can receive energy and release energy, but does not significantly exchange matter. This makes the earth a closed system.
True
Adenosine triphosphate is often cited as the energy currency of the cell. Which of the following molecules would theoretically have the same energy transfer capacity as ATP?
UTP GTP NOT: ADP,CMP,GDP
A small, non-protein molecule that is necessary for an enzyme catalyzed reaction is called a/an
activator
The active site of an enzyme is the region that
binds allosteric regulators of the enzyme
The cytochrome b-f protein in photosynthesis is analogous to (blank) in cell respiration?
complex III
The ATP produced in the chloroplast stomata is
only used in the Calvin cycle
In linear electron flow, reduced plastocyanin passes on its electrons to
p700+
Energy transfers are never 100% efficient. This fact is expressed in
the second law of thermodynamics
A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because
the starch solution has less free energy than the sugar solution
The mathematical expression for the change in free energy of a system is △G =△H-T△S. Which of the following is correct?
△G is the change in free energy.
