bsc quiz

7) Which of the following is considered an open system? A) an organism B) liquid in a corked bottle C) a sealed terrarium D) food cooking in a pressure cooker

A) an organism

30) .How do enzymes speed up chemical reactions? A Increase activation energy B. Lower activation energy C. We're not entirely sure D. A and C E. B and C

B. lower activation energy

11)) Which of the following is (are) true for anabolic pathways? A) They do not depend on enzymes. B) They are usually highly spontaneous chemical reactions. C) They consume energy to build up polymers from monomers. D) They release energy as they degrade polymers to monomers.

C) They consume energy required to build up polymers from monomers

8)Which of the following statements is a logical consequence of the second law of thermodynamics? A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. B) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. C) Every energy transfer requires activation energy from the environment. D) Every chemical reaction must increase the total entropy of the universe. E) Energy can be transferred or transformed, but it cannot be created or destroyed.

D) Every chemical reaction must increase the total entropy

9)) Which of the following statements is representative of the second law of thermodynamics? A) Conversion of energy from one form to another is always accompanied by some gain of free energy. B) Heat represents a form of energy that can be used by most organisms to do work. C) Without an input of energy, organisms would tend toward decreasing entropy. D) Cells require a constant input of energy to maintain their high level of organization. E) Every energy transformation by a cell decreases the entropy of the universe.

D) Every energy transformation by a cell decreases the entropy of the universe

Which of the following is an example of potential rather than kinetic energy? A) a boy mowing grass B) water rushing over Niagara Falls C) a firefly using light flashes to attract a mate D) a food molecule made up of energy-rich macromolecules E) an insect foraging for food

D) a food molecule made up of energy-rich macromolecules

which of the following statements is true concerning catabolic pathways? A) They combine molecules into more energy-rich molecules. B) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP. C) They are endergonic. D) They are spontaneous and do not need enzyme catalysis. E) They build up complex molecules such as protein from simpler compounds.

E) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.

10)Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? A) catalysis B) metabolism C) anabolism D) dehydration E) catabolism

E) catabolism

20. All of the following statements regarding enzymes are true EXCEPT a. Enzymes are carbohydrates that function as agents that change the rate of reaction without being consumed in the reaction. b.. Enzymes allow molecules to react in metabolism by lowering activation energies. c. Each type of enzyme has a uniquely shaped active site that gives it specificity. d. Enzymes are very sensitive to environmental conditions that influence the weak chemical bonds responsible for their three-dimensional structure. e. Some enzymes change shape when inhibitors bind to specific allosteric receptor sites.

a. Enzymes are carbohydrates that function as agents that change the rate of reaction without being consumed in the reaction.

12. The __________ law of thermodynamics states that energy can be neither created nor destroyed. a. first b. second c. third d. fourth e. fifth

a. First

24. According to the second law of thermodynamics a. the entropy of the universe is constantly increasing b. every energy transfer requires activation energy from the environment c. the total amount of energy in the universe is conserved or constant d. for every action there is an equal and opposite reaction e. energy can be transferred or transformed, but it can be neither created nor destroyed.

a. The entropy of the universe is constantly increasing

16. __________ includes all chemical reactions occuring with in a cell. a. metabolism b. anabolism c. catabolism d. exernismn

a. metabolism

18. Which of the following represents work normally done by cells? a. synthesis of complex molecules b. nutrient uptake and waste elimination c. internal and external d. movement e. All of these

all of these

15. __________ is the endergonic synthesis of molecules. a. metabolism b. anabolism c. catabolism d. exernism

b. anabolism

14. An unfavorable reaction that requires an input of energy in order to proceed is __________. a. exergonic b. endergonic c. impossible d. none of these

b. endergonic

22. Which of the following statements is true concerning catabolic pathways? a. They combine molecules into more complex and energy-rich molecules. b. They are usually coupled with anabolic pathways to which they supply energy in the form of ATP c. They involve endergonic reactions that break complex molecules into simpler ones d. They do not need enzyme catalysts e. They build up complex molecules such as protein from simpler compounds.

b. they are usually coupled with anabolic pathways to which they supply energy in the form of ATP

23. The hydrolysis of sucrose by the enzyme sucrase results in a. bringing glucose and fructose together to form sucrose b. the release of free water from sucrose as the linkage between glucose and fructose is broken. c. breaking the bond between glucose and fructose by breaking a water molecule and adding an H+ to one and an OH- to the other d. production of water from the sugar as bonds are broken between the glucose monomers e. utilization of water as a linkage is formed between glucose and fructose to form sucrase.

c. Breaking the bond between glucose and fructose by breaking a water molecule and adding an H+ to one and then OH- to the other

__________ is the exergonic breakdown of substrates. a. metabolism b. anabolism c. catabolism d. exernism

c. catabolism

19. Which of the following is the most randomized form of energy? a.Light b.Electrical c.Heat d.Mechanical e.Chemical

c. heat

27. What is adenosine made of? a. Adenine and phosphate b. Adenine and pentose c. Adenine and deoxyribose d. Adenine and ribose

d adenine and ribose

26. Which is not true of enzyme behavior? a. Enzyme shape may change following initial binding of the substrate. b. The active site of an enzyme orients its substrate molecules, thereby promoting interaction of their reactive parts. c. All enzymes have an active site where substrates are temporarily bound. d. An individual enzyme can catalyze a wide variety of different reactions. e. Enzymes are sensitive to pH changes.

d. an individual enzyme can catalyze a wide variety of different reactions

25. Which term most precisely describes the general process of combining small molecules to form large molecules ? a. metabolism b. dehydration c. catabolism d. anabolism e. endergonic reaction

d. anabolism

17. If the nonprotein component of an enyzme is firmly attached to the protein it is called a(n) __________. a. apoenzyme b. coenzyme c. holoenzyme d. prosthetic group

d. prosthetic group

29.What is an enzyme inhibitor? A.Something that speeds up the enzyme B.Something that slows down the enzyme C.Something that totally stops the enzyme D.Something that denatures the enzyme

d. something that denatures the enzyme

a chemical reaction that has a positive 🔼G is correctly described as

endergonic

21. The transfer of free energy from exergonic pathways to endergonic pathways is best called a.feedback inhibition b. entropy c. competitive inhibition d. energy coupling e. cooperativity

energy coupling

Catabolism is to anabolism as __________ is to __________.

exergonic; endergonic

what is the change in free energy in a system at chemical equilibrium?

no net change

Most cells cannot harness heat to perform work because

temperature is usually uniform throughout a cell