FREE BIOLOGY AND STUDY GAMES ABOUT CH. 6 EXAM

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FREE BIOLOGY AND STUDY GAMES ABOUT CH. 6 EXAM

QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -62 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: a plot of activation rate (velocity) against temperature for an enzyme indicates little activity at 10 degrees C & 45 degrees C, with peak activity at 35 degrees

• explain the low velocity at 10 degrees C.

Answer:

There is too little activation energy available Question 2: consider the growth of a farmer's crop over a season. What would be a possible limitation imposed by the 1st or 2nd law of thermodynamics?

Answer:

to obey the 1st law, the crops must represent an open system.Question 3: much of the suitability of ATP as an energy intermediary is related to the instability of the bonds between the phosphate groups. these bonds are unstable because ____.

Answer:

the negatively charged phosphate groups vigorously repel one another and the terminal phosphate group is more stable in water than it is in ATP.

Question 4: Molecules A & B contain 110 kcal/mol of free energy & molecules C & D contain 150 kcal/mol of energy. A & B are converted to C &

• What can be concluded?

Answer:

the reaction that proceeds to convert A & B to C & D is endergonic; the products are more organized than the reactants.Question 5: T or F? enzymes speed up the rate of the reaction without changing the DG for the reaction.

Answer:

True Question 6: T or F? Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.

Answer:

True

Question 7: _____ is the study of how energy flows through living organisms.

Answer:

bioenergetics

Question 8: which molecule has the most free energy per molecule?

Answer:

a starch olecule

Question 9: What is the most abundant form of energy in a cell?

Answer:

chemical energy

Question 10: T or F? An enzyme is consumed during the reaction it catalyzes.

Answer:

False

Question 11: at an organismal level, complex and beautifully ordered structures result from ____ ____ that use simpler starting materials.

Answer:

biological processes

Question 12: what is changed by the presence of an enzyme in a reaction?

Answer:

the activation energy Question 13: T or F? the proton movement against a gradient of protons would be an example of cellular work accomplished with the free energy derived from the hydrolysis of ATP.

Answer:

True Question 14: the use of an exergonic process to drive an endergonic one is called ____ _____.

Answer:

energy coupling Question 15: T or F? Free energy is the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell.

Answer:

True Question 16: the process of stabilizing the structure of an enzyme in its active form by the binding of a molecule is an example of _____.

Answer:

allosteric regulation Question 17: T or F? We can't think of free energy as a measure of a system's instability- it's tendency to change to a more stable state.

Answer:

False

Question 18: enzyme activity is affected by pH because ______.

Answer:

high or low pH may disrupt hydrogen bonding or ionic interactions and thus change the shape of the active site.

Question 19: state the relevance of the 1st law of thermodynamics to biology.

Answer:

energy can be freely transformed among different forms as long as the total energy is conserved.Question 20: ATP hydrolysis being used to drive the active transport of an ion into the cell against the ion's concentration gradient is an example of ____ _____.

Answer:

energy coupling Question 21: above a certain substrate concentration, the rate of an enzyme-catalyzed reaction drops as the enzymes become saturated. what would lead to a faster conversion of substrate into product under these saturated conditions?

Answer:

an increase of concentration in enzyme & increasing the temperature by a few degrees.

Question 22: what is meant by the "induced fit" of an enzyme?

Answer:

the enzyme changes its shape slightly as the substrate binds to it.Question 23: T or F? Organisms acquire energy from, and lose energy to, their surroundings.

Answer:

True Question 24: Which law states the following? The energy of the universe is constant; energy can be transformed, but cannot be created or destroyed. Also called the "principle of conservation of energy"

Answer:

the first law of thermodynamics