"Conservation of energy" refers to the fact that _____.
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
Energy is observed in two basic forms: potential and kinetic. Which of the following correctly matches these forms with a source of energy?
The process of cellular respiration, which converts simple sugars such as glucose into CO2 and water, is an example of _____.
Which of the following statements about the combustion of glucose with oxygen to form water and carbon dioxide (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O) is correct?
Which of the following statements about equilibrium of chemical reactions is correct?
Select the highest energy form of adenosine from the following images. Adenosine triphosphate (ATP) is the high-energy form of adenosine because it contains the most phosphate groups (three). This molecule fuels many different endergonic (energy-requiring) enzymatic processes in biological organisms. ATP molecules diffuse or are transported to the place where the energy is needed and deliver chemical energy from the breaking of their phosphate bonds.
The following reaction
A --> B + C + heat
is a(n) _____ reaction.
A(n) _____ reaction occurs spontaneously.
Which of these reactions requires a net input of energy from its surroundings?
In cells, what is usually the immediate source of energy for an endergonic reaction?
The hydrolysis of ATP provides the energy needed for an endergonic reaction.
The energy for an endergonic reaction comes from a(n) _____ reaction.
What is the fate of the phosphate group that is removed when ATP is converted to ADP?
Select the INCORRECT association.
enzyme ... protein
exergonic ... uphill
exergonic ... spontaneous
potential energy ... positional energy
kinetic energy ... motion
What is energy coupling?
What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?
Which of the following statements about ATP (adenosine triphosphate) is correct?
Consider a situation in which the enzyme is operating at optimum temperature and pH, and has been saturated with substrate. What is your best option for increasing the rate of the reaction?
Increase the enzyme concentration If an enzyme is saturated with substrate, and it is operating at optimum pH and optimum temperature, there is very little that can be done except to increase the enzyme concentration. Some enzymes can be activated further by allosteric activators, in which case one might add some activator to the reaction. But otherwise, increasing the enzyme concentration is the only option.
Competitive inhibitors compete physically and structurally with the substrate for an enzyme’s active site; they can be outcompeted by adding extra substrate. Noncompetitive inhibitors do not compete for the active site, but inhibit the enzyme by binding elsewhere and changing the enzyme’s shape. Irreversible inhibitors bind directly to the active site by covalent bonds, which change the structure of the enzyme and inactivate it permanently. Most medications are enzyme inhibitors of one kind or another.
You have added an irreversible inhibitor to a sample of enzyme and substrate. At this point, the reaction has stopped completely.
What can you do to regain the activity of the enzyme?
You have an enzymatic reaction proceeding at the optimum pH and optimum temperature. You add a competitive inhibitor to the reaction and notice that the reaction slows down.
What can you do to speed the reaction up again?
Add more substrate; it will outcompete the inhibitor and increase the reaction rate.
Competitive inhibition can be overcome by adding more substrate to outcompete the inhibitor. Many drugs used to treat different medical conditions, including hypertension, are competitive inhibitors. It is fairly easy to make a molecule that is similar in structure to a particular substrate because the known enzyme’s shape can be used as a model of what the molecule needs to look like. It is more difficult to make a noncompetitive inhibitor because it is less obvious what the noncompetitive inhibitor’s shape and structure should be.
The Haber process is typically carried out at a temperature of approximately 500∘C. What would happen to the rate of the forward reaction if the temperature were lowered to 100∘C?
What would happen to the rate of the forward reaction if the concentration of nitrogen were decreased?
Which of the following would increase the rate of the reverse reaction?
What will happen to the rates of the forward and reverse reactions when a catalyst is added?
Rank these by reaction rate, as measured by the rate of product formation per unit time, from lowest reaction rate to highest reaction rate. To rank items as equivalent, overlap them.
look at item 13
A substrate binds at an enzyme’s active site; the enzyme typically recognizes the specific shape of its substrate. A cofactor, such as an inorganic ion or vitamin, may bind to the enzyme and assist in catalyzing the reaction. The reaction environment must be appropriate for catalysis to proceed. An enzyme will denature, or change its shape and lose its biological activity, at too high a temperature or at a pH outside the enzyme’s optimal range.
Which of the following is NOT a way in which an enzyme can speed up the reaction that it catalyzes?
The binding of a compound to an enzyme is observed to slow down or stop the rate of the reaction catalyzed by the enzyme. Increasing the substrate concentration reduces the inhibitory effects of this compound. Which of the following could account for this observation?
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _______ is to _______.
Which of the following statements about feedback regulation of a metabolic pathway is correct?
Which of the following metabolic processes can occur without a net influx of energy from some other process?
If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to
Some bacteria are metabolically active in hot springs because
If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?
How does an enzyme increase the rate of the chemical reaction it catalyzes?