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Chemistry of Life Test #1
Biology
Name:____________________________
1. Scientists have found geysers on one of Saturn’s moons. The geysers release water vapor
containing organic compounds, which may indicate the presence of life. Which of the
following elements is most likely in the organic compounds?
A. carbon
B. chlorine
C. iron
D. zinc
2. Which of the following represents a compound whose atoms contain a double bond?
a. NH2
c. Cl-Cl
b. O=O
d. H-H
3. Some bacteria live in hot springs. Their cells contain enzymes that function best
at temperatures of 70°C. At a temperature of 95°C, how will the enzymes in these
bacterial cells most likely be affected?
A. The enzymes will be destroyed by lysosomes.
B. The enzymes will lose their shape be unable to function.
C. The enzymes will require less energy to function than at 70°C.
D. The enzymes will not increase the rate of reactions as much as they
would at 70°C.
4. When hydrogen and oxygen combine and form water [H2 + O
H2O], how many
atoms of each reaction does the product have:
a. Two hydrogen atoms and two
c. One hydrogen atom and one
oxygen atoms
oxygen atom
b. One hydrogen atom and two
d. Two hydrogen atoms and one
oxygen atoms
oxygen atom
5. A scientist is analyzing a sample of tissue from a plant. Which of the following
elements will be most abundant in the sample?
A. zinc and copper
B. sodium and chlorine
C. carbon and hydrogen
D. magnesium and calcium
6. Resistance to antibiotics results from variations in the genes of Streptococcus
pneumoniae. Which type of macromolecule stores genetic information
in Streptococcus pneumoniae?
A. carbohydrate
B. fatty acid
C. nucleic acid
D. protein
7. Students digging near their school unearthed four objects. One of the objects was part
of the exoskeleton of an insect. The table below shows the elements that make up
the objects.
Object
Chemical
Composition
W
chlorine,
sodium
X
oxygen,
silicon
Y
carbon,
hydrogen,
oxygen
Z
aluminum,
silicon,
oxygen,
hydrogen
Based on the chemical analysis, which object is most likely from the exoskeleton?
A. object W
B. object X
C. object Y
D. object Z
8. A student is preparing to run in a school track competition. For the quickest source
of energy, the student should eat a food that contains a high percentage of
A. carbohydrates.
B. fat.
C. proteins.
D. sodium.
9. In the human body, fibrinogen is necessary for sealing cuts and stopping the loss of
blood. Since fibrinogen is made of chains of amino acids, it is an example of which
type of organic molecule?
A. carbohydrate
B. protein
C. fatty acid
D. nucleic acid
10. Which of the following roles does an enzyme play when the body breaksdown
sucrose (table sugar) into glucose and fructose?
A. An enzyme decreases the body’s need for sucrose.
B. An enzyme increases the amount of sucrose available.
C. An enzyme increases the rate at which the sucrose breaks down.
D. An enzyme decreases the amount of fructose and glucose product available.
11. What do disaccharides, such as sucrose, and polysaccharides, such as starch,
have in common?
A. They are lipids made of fatty acids.
B. They are proteins made of amino acids.
C. They are nucleic acids made of nucleotides.
D. They are carbohydrates made of monosaccharides.
12. Lemurs’ bodies are adapted to efficiently store energy for times when food is
scarce. This adaptation may help to explain how lemur ancestors survived the trip
across the Mozambique Channel from mainland Africa to Madagascar.
Which of the following types of molecules are primarily used for long-term energy
storage in the lemur?
A. lipids
B. monosaccharides
C. nucleic acids
D. proteins
13. Which list contains the six elements that make up the majority of the mass of
living things?
A.
B.
C.
D.
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur
Carbon, Calcium, Nitrogen, Oxygen, Phosphorus, Sulfur
Carbon, Calcium, Nitrogen, Oxygen, Potassium, Sulfur
Carbon, Hydrogen, Nitrogen, Oxygen, Potassium, Sulfur
14. The graph below shows how the rate of a reaction changes over a range of pH values.
Remember that enzymes are catalyst that can easily be denatured when there is a
sudden change in pH.
Which of the following conclusions is supported by the data?
A. The enzyme functions best at a pH of 5.
B. The enzyme functions best at a pH of 7.
C. The reaction rate is higher around a pH 8.0 than around a pH 5.0.
D. The enzyme functions best at a pH of 6.
15. What is one way that fats are used in the body?
A. for storing energy
B. for encoding genetic information
C. as the building blocks of antibodies
D. as the building blocks of hemoglobin
16. Which of the following is the main reason that humans need to include
carbohydrates in their diet?
A. Carbohydrates are broken down in cells for energy.
B. Carbohydrates combine to form many different proteins.
C. Carbohydrates act as catalysts to speed up chemical reactions.
D. Carbohydrates are the building blocks for cell growth and repair.
17. One category of organic compounds contains molecules composed of 3 long fatty
acid chains. The chains may be saturated or unsaturated. Which of the following
categories of organic compounds contains these molecules?
A. carbohydrates
B. lipids
C. nucleic acids
D. proteins
18. Some bacteria contain a substance called nitrogenase. Nitrogenase catalyzes the
chemical reaction that converts atmospheric nitrogen (N2) into ammonia (NH3).
Nitrogenase is an example of which of the following?
A. a sugar
B. an enzyme
C. a nucleotide
D. an amino acid
19. Which of the following categories of organic molecules is correctly paired with one of
its functions?
A. nucleic acids—digest dead cells
B. lipids—give quick energy to cells
C. carbohydrates—store genetic information
D. proteins—provide structure in skin, hair, and nails
20. An example of denaturation is:
a. an egg white changing from clear to a solid white after being cooked
b. a protein folding
c. a polypeptide forming
d. an amino acid substitution
21. Enzymes are classified as:
a. carbohydrates c. nucleic acids
b. lipids
d. proteins
22. Substrates bind to enzymes at the:
a. activation energy
b. active site
c. carboxyl group
d. hydroxyl group
23. When this type of organic compound forms, the amino acid chain must
twist, fold, and coil into a unique and very specific shape to function
properly
a. proteins
c. nucleic acids
b. lipids
d. carbohydrates
24. A carbohydrate made up of two sugar units, sucrose for example, is a(n)
a. disaccharide
b. monosaccharide
c. polysaccharide
d. steroid
25. Cortisone is an example of a:
a. carbohydrate
c. steroid
b. saturated fat
d. unsaturated fat
Extra Credit: What kind of chemical reaction is being depicted in the graph
a. exothermic
b. endothermic