Enzymes, photosynthesis, cellular respiration Flashcards
Consider this reaction: A + Y —> AY (ΔG= - 10 kcal). Which of the following statements is TRUE?
A small amount of energy (activation) must be supplied to start the reaction, which then proceeds with a release of energy
The reaction is exergonic
The reaction can be coupled to an endergonic reaction
All options are correct
All options are correct
Which of the following is a TRUE statement about CATABOLIC pathways?
These occur when simple molecules are combined to form complex molecules
All options are correct
Photosynthesis is an example of a catabolic pathway
Energy is added as the pathway progresses
Involve reactions that progress with a net release of energy.
Involve reactions that progress with a net release of energy.
Digestin is an enzyme that catalyzes the following reaction:
X + Y —> Z (ΔG = -10 kCal)
What is the role of Digestin?
Digestin functions as an inhibitor
Digestin makes the ΔG of the reaction more negative
Digestin lowers the activation energy of the reaction
Digestin provides energy for the reaction to occur
Digestin lowers the activation energy of the reaction
Which statement about a competitive inhibitor is TRUE?
It helps speed up reactions
It binds to the active site of an enzyme
All options are correct
It binds to a site that is separate from the active site of the enzyme
It binds to the substrate
It binds to the active site of an enzyme
Which of the following examples of cellular work DO NOT use ATP?
Transport work, such as the active transport of an ion into a cell
Mechanical work, such as vesicle movement on microtubules
Chemical reactions that are endergonic
The production of heat, which raises the temperature of the cell
The production of heat, which raises the temperature of the cell
According to the SECOND law of thermodynamics which of the following is TRUE?
The total amount of energy in the universe is constant
Energy conversions increase the order of the universe
Energy can be recycled in an ecosystem
Every energy transfer or transformation increases the entropy of the universe
Every energy transfer or transformation increases the entropy of the universe
Which of the following events takes place in the thylakoid of the chloroplast?
Transfer of electrons through a series of redox reactions
Breakdown of an Acetyl Coenzyme-A to Carbon Dioxide
Substrate-level phosphorylation to make ATP
The Calvin Cycle to make Glucose
Oxidation of Glucose into two Pyruvate molecules
Transfer of electrons through a series of redox reactions
For the reaction below,__________ is oxidized and ____________ is reduced.
Succinate + FAD -------------> Fumarate + FADH2
FAD, FADH2 Fumarate, FADH2 Succinate, Fumarate Succinate, FAD Fumarate, NADH
Succinate, FAD
Which of the following is TRUE about substrate level phosphorylation to make ATP?
All options are correct
Occurs during Chemiosmosis
Occurs in Glycolysis and Citric acid cycle
Needs an ATP synthase
Involves electron transport chain components
Occurs in Glycolysis and Citric acid cycle
In your undergraduate research lab, you purified an enzyme that was active in the human stomach where the pH is acidic. You added water and a specific substrate to it and left it at 4 °C for several hours. Unfortunately, no product was formed. Remembering your BIO311C class, what would you change so that the reaction occurs?
Increase the pH and decrease the temperature of the reaction
Decrease the pH and increase the temperature of the reaction
Decrease the temperature and the pH of the reaction
Increase the temperature and the pH of the reaction
Decrease the pH and increase the temperature of the reaction
In the reaction:
Ammonia + Glutamate ———-> Glutamine (ΔG = +10 kcal/mol)
Which of the following statements is TRUE?
The reaction can couple with a reaction whose ΔG = -3 kcal/mol
Glutamine has more free energy than Ammonia and Glutamate
The reaction is spontaneous
All options are correct
The reaction is exergonic
Glutamine has more free energy than Ammonia and Glutamate
In photophosphorylation, what is the most DIRECT source of energy that is used to form ATP?
Energy released from the electron transport chain proteins
Energy released by H+ pumps
Energy released by NADH forming NAD+
Energy released from movement of H+ down concentration gradient
Energy released from substrate level phosphorylation
Energy released from movement of H+ down concentration gradient
If you transfer a mitochondrion with its outer membrane removed (with all inner membrane complexes intact) to a beaker containing solution of low pH, what will be a direct consequence?
Light reactions will occur Glycolysis will occur Water will be split, releasing O2 Pyruvate will be oxidized ATP will be made
ATP will be made
Which of the following is a characteristic of linear (non-cyclic) electron flow in light reactions?
Occurs only when NADPH concentration is high in cells Oxidation of pyruvate occurs All options are correct Generates O2, NADPH, and ATP Uses only PS I
Generates O2, NADPH, and ATP
In the ABSENCE of O2, what is a role of fermentation in cells?
Facilitate transport of NADH and FADH2 down electron transport chain
Pump protons
Make ATP by oxidative phosphorylation
Oxidize pyruvate
Regenerate NAD+
Regenerate NAD+
