Biofuels Pre-Test

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1.	Carbon-12 is the most common isotope of carbon. It has 6 protons, 6 neutrons, and 6 electrons. Of its 6 electrons, 4 are valence electrons. How many covalent bonds can a carbon atom form?
a. | 1
b. | 4
c. | 6
d. | 12

____	2.	Which of the following statements about enzymes is NOT true?
a. | Enzymes work best at a specified pH.
b. | All enzymes have the same shape as their substrates.
c. | Enzymes are proteins.
d. | The shape of an enzyme allows it to do its job.

____	3.	Which of the following statements is true about catalysts?
a. | Catalysts slow down the rate of chemical reactions.
b. | All catalysts are enzymes.
c. | Catalysts are used up during a chemical reaction.
d. | Catalysts lower the activation energy of a chemical reaction.

____	4.	The primary function of the cell wall is to
a. | support and protect the cell.
b. | store DNA.
c. | direct the activities of the cell.
d. | help the cell move.

____	5.	Unlike the cell membrane, the cell wall is
a. | found in all organisms.
b. | composed of a lipid bilayer.
c. | selectively permeable.
d. | a rigid structure.

____	6.	Because of biogeochemical cycling, 
a. | human activity has no effect on elements, chemical compounds, and other forms of matter.
b. | living organisms are not limited by any one nutrient.
c. | nutrients are circulated throughout the biosphere.
d. | many nutrients do not reach toxic concentrations in the biosphere.

____	7.	Carbon cycles through the biosphere in all of the following processes EXCEPT
a. | photosynthesis.
b. | transpiration.
c. | burning of fossil fuels.
d. | decomposition of plants and animals.

____	8.	How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
a. | by changing the shape of the enzyme's active site
b. | by decreasing the activation energy of the reaction
c. | by binding at the active site of the enzyme
d. | by acting as a coenzyme for the reaction

____	9.	

Which curve(s) on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot springs at temperatures of 70°C or higher?
a. | curves 1 and 5
b. | curves 3 and 4
c. | curves 2 and 5
d. | curves 3 and 5

____	10.	Which of the following statements regarding enzymes is true?
a. | Enzymes increase the rate of a reaction by making the reaction more exergonic.
b. | Enzymes increase the rate of a reaction by lowering the activation energy barrier.
c. | Enzymes make the rate of a reaction independent of substrate concentrations.
d. | Enzymes increase the rate of a reaction by reducing the rate of reverse reactions.

____	11.	A molecule with the chemical formula C_6H_12O_6 is probably a
a. | monosaccharide
b. | carbohydrate and monosaccharide only.
c. | carbohydrate and lipid only.
d. | carbohydrate.

____	12.	Which of the following is true of both starch and cellulose?
a. | They are both polymers of glucose.
b. | They are cis–trans isomers of each other.
c. | They can both be digested by humans.
d. | They are both used for energy storage in plants.

____	13.	Which of the following is true of cellulose?
a. | It is a polymer composed of enantiomers of glucose.
b. | It is a storage polysaccharide for energy in plant cells.
c. | It is digestible by bacteria in the human gut.
d. | It is a major structural component of plant cell walls.

____	14.	Which of the following locations is the reservoir for carbon for the carbon cycle?
a. | sediments and sedimentary rocks
b. | atmosphere
c. | fossilized plant and animal remains (coal, oil, and natural gas)
d. | all of the above

Biofuels Pre-Test
Answer Section

MULTIPLE CHOICE

	1.	ANS:	B	PTS:	1	DIF:	L3	REF:	p. 45
OBJ:	2.3.1 Describe the unique qualities of carbon.	STA:	B.1.1
MSC:	synthesis

	2.	ANS:	B	PTS:	1	DIF:	L3	REF:	p. 52 | p. 53
OBJ:	2.4.3 Explain why enzymes are important to living things.		
STA:	B.1.1 | B.1.2 | B.1.3		MSC:	synthesis

	3.	ANS:	D	PTS:	1	DIF:	L2	REF:	p. 52
OBJ:	2.4.3 Explain why enzymes are important to living things.		
STA:	B.1.1 | B.1.2 | B.1.3		TOP:	Foundation Edition	
MSC:	analysis

	4.	ANS:	A	PTS:	1	DIF:	L1	REF:	p. 203
OBJ:	7.2.5 Describe the function of the cell membrane.	STA:	B.2.1 | B.2.2
TOP:	Foundation Edition		MSC:	knowledge

	5.	ANS:	D	PTS:	1	DIF:	L3	REF:	p. 204
OBJ:	7.2.5 Describe the function of the cell membrane.	STA:	B.2.1 | B.2.2
MSC:	analysis

	6.	ANS:	C	PTS:	1	DIF:	L3	REF:	p. 79 | p. 80 | p. 82
OBJ:	3.4.1 Describe how matter cycles among the living and nonliving parts of an ecosystem.
STA:	B.3.4 | B.3.5	TOP:	Foundation Edition		MSC:	analysis

	7.	ANS:	B	PTS:	1	DIF:	L3	REF:	p. 82 | p. 83
OBJ:	3.4.1 Describe how matter cycles among the living and nonliving parts of an ecosystem.
STA:	B.3.4 | B.3.5	MSC:	application

	8.	ANS:	A	PTS:	1	TOP:	Concept 8.4	MSC:	Knowledge/Comprehension

	9.	ANS:	D	PTS:	1	TOP:	Concept 8.4	MSC:	Application/Analysis

	10.	ANS:	B	PTS:	1	TOP:	Concept 8.4	MSC:	Knowledge/Comprehension

	11.	ANS:	B	PTS:	1	TOP:	Concept 5.2	MSC:	Knowledge/Comprehension

	12.	ANS:	A	PTS:	1	TOP:	Concept 5.2	MSC:	Knowledge/Comprehension

	13.	ANS:	D	PTS:	1	TOP:	Concept 5.2	MSC:	Knowledge/Comprehension

	14.	ANS:	D	PTS:	1	TOP:	Concept 55.4		
MSC:	Knowledge/Comprehension