Download Organic Molecules Quiz

Biology II
Ms. Chen
Name:
Date:
Organic Molecules Quiz
Multiple Choice (2 pts each)
Directions: Circle the best answer.
1. The diagram below shows the basic structure of a cell’s plasma membrane.
What is the primary function of lipid molecules in the plasma membrane?
A. to provide an energy source for most cell activities
B. to provide a substrate for enzyme activity in the cell
C. to provide a place to collect and store waste products within the cell
D. to provide a barrier to the movement of substances in and out of the cell
2. Plant species such as the sesame plant and the coconut palm have large amounts of lipids
in their seeds. Which of the following is the most likely function of these lipids?
A. to store energy for the seedlings
B. to absorb water for the seedlings
C. to encode most of the genetic information in the seedlings
D. to speed up most of the chemical reactions in the seedlings
3. The graph below shows the percent by mass of six common elements in the human body.
What are elements 5 and 6?
A. zinc and sulfur
B. sodium and iron
C. carbon and oxygen
D. chlorine and phosphorus
4. Carbohydrates, lipids, proteins, and nucleic acids are organic molecules essential for life.
Which of the following elements makes the large structures of these organic molecules
possible?
A. calcium
B. carbon
C. oxygen
D. zinc
5. Peptidoglycan is a compound in the cell walls of many bacteria. Which of the following
elements are most abundant in peptidoglycan?
A. aluminum and sodium
B. carbon and hydrogen
C. chlorine and iron
D. iodine and potassium
6. Cellulose is a compound found in plants. It is made of a long chain of molecules with
ringed structures. The molecules contain mostly carbon, hydrogen, and oxygen atoms in a
ratio of approximately 1 carbon : 2 hydrogen : 1 oxygen. To which category of biological
molecules does cellulose belong?
A. carbohydrates
B. nucleic acids
C. phospholipids
D. proteins
7. Fructose, sucrose, and starch are all examples of
A. carbohydrates.
B. lipids.
C. nucleic acids.
D. proteins.
8. Many farm animals eat hay, which is made by cutting and drying plants such as ryegrass
and timothy grass. Scientists analyzed the composition of hay after it was cut and again
after it was dried. The amounts of which common biological elements would have
decreased the most as the hay dried?
A. sulfur and calcium
B. phosphorus and zinc
C. oxygen and hydrogen
D. nitrogen and chlorine
9. The table below provides information about the composition and function of four
important molecules in living organisms.
Molecule
Composition
Function
1
amino acids
reaction
catalyst
2
fatty acids
membrane
component
3
monosaccharides
energy
source
4
nucleotides
genetic
information
Which of the molecules in this table is a carbohydrate?
A. 1
B. 2
C. 3
D. 4
10. Which group of organic compounds contains fatty acids?
A. carbohydrates
B. lipids
C. nucleic acids
D. proteins
11. Cellulose is a complex carbohydrate that makes up the cell walls of plants. Which of the
following elements are main components of cellulose?
A. calcium and chlorine
B. carbon and hydrogen
C. potassium and chlorine
D. sodium and hydrogen
12. The body structure of a reef-building coral consists of a hard skeleton covering soft
tissue. Which of the following elements is most common in the coral’s soft tissue?
A. carbon
B. chlorine
C. sodium
D. zinc
13. 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 results of a chemical analysis of
the objects.
Object
Chemical Composition
W
chlorine, sodium
X
oxygen, silicon
Y
carbon, hydrogen, nitrogen,
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
14. 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 simple sugars.
15. 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.
16. Which type of molecule in the yolk of a chicken egg provides the most energy for a
developing chick?
A. lipid
B. nucleic acid
C. salt
D. Water
17. Salivary amylase breaks down which class of organic molecules?
A. carbohydrates
B. lipids
C. nucleic acids
D. Proteins
18. Fatty acids are one of the products that result from the action of lipase in the digestive
system. What is one way that fatty acids 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
19. Which of the following best describes the composition of a nucleotide?
A. a pair of six-carbon rings attached to each other
B. a carbon atom joined to hydrogen and three functional groups
C. a chain of carbon atoms with a carboxyl group bonded to one end
D. a five-carbon sugar attached to a phosphate group and a nitrogenous base
20. 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.

Open Response (10 pts)
Directions: Answer each part of the question completely.
The diagram below shows the molecular structure of glucose.
Glucose is a simple carbohydrate that is important to living organisms.
a. Describe the primary function of glucose in cells.
b. Simple sugars like glucose can be used to make larger organic molecules.
Identify two larger molecules made from simple sugars.