Download Biochemistry Practice Questions

Name: __________________
Mrs. Lambiase
Organic Compounds
Practice Questions
1. Which are the four most abundant elements in living cells?
a. Carbon, oxygen, nitrogen, sulfur
b. Carbon, oxygen, hydrogen, nitrogen
c. Carbon, oxygen, sulfur, phosphorus
d. Carbon, sulfur, hydrogen, magnesium
2. Which pair of compounds can be classified as inorganic?
a. Nucleic acids and minerals
b. Proteins and water
c. Water and salts
d. Nucleic acids and proteins
3. Which chemical formula represents an organic compound?
a. H2O
b. NaCl
c. NH3
d. C6H12O6
4. The most abundant compound in cytoplasm is
a. Fat
b. Water
c. Protein
d. Carbohydrates
5. One of the carbon compounds found in a cell has twice as
many hydrogen atoms as oxygen atoms. This compound most
likely belongs to the group of substances known as
a. Nucleic acids
b. Lipids
c. Proteins
d. Carbohydrates
6. A compound whose chemical composition is most closely
related to maltose is
a. Starch
b. ATP
c. Protein
d. RNA
7. Which general formula best represents a monosaccharide?
a. C2O
b. C2HO
c. CHO2
d. CH2O
8. Water is produced as a waste product by the process of
a. Dehydration synthesis
b. Protein ingestion
c. Carbohydrate digestion
d. Absorption of minerals
9. What are the most common building blocks of fats?
a. Alcohol and carbohydrates
b. Alcohol and proteins
c. Glycerol and amino acids
d. Glycerol and fatty acids
10.Compared to carbohydrates, the ratio of hydrogen to
oxygen in lipids is
a. The same
b. Sometimes smaller
c. Always smaller
d. Always greater
11. As a class of compounds, lipids include
a. Fats and oils
b. Fats, carbohydrates, and proteins
c. Alcohols and acids
d. Sugars and starches
12.Fertilizers containing radioactive nitrogen compounds are
used in growing experimental plants. In which molecules
would these compounds be detected first?
a. Sugar
b. Starch
c. Proteins
d. Fats
13.Amino acids are required in the human diet principally for
the synthesis of
a. Proteins
b. Sugars
c. Starches
d. Lipids
14.A sample of small, soluble, organic molecules was analyzed
and found to contain the elements carbon, oxygen,
hydrogen, and nitrogen. It is most likely that the molecules
were
a. Lipids
b. Fatty acids
c. Simple sugars
d. Amino acids
15.The process by which amino acids are chemically joined
together is called
a. Pinocytosis
b. Hydrolysis
c. Nitrogen fixation
d. Dehydration synthesis
16.Protein has a great potential for variation of structure
because
a. Many amino acids may combine in a number of ways
b. Different types of amino acids may occur in pairs
c. Fatty acids may vary
d. Nucleotides may vary
17.Which substance is classified as a protein?
a. Sucrose
b. Glycerol
c. Starch
d. Hemoglobin
18.Molecules made up of long chains of repeating units are
called
a. Polymers
b. Enzymes
c. Fatty acids
d. DNA
19.The formula C68H103O45N17S2 most likely represents a
a. Lipid
b. Polysaccharide
c. Starch
d. proteins
20. Which type of organic compound has molecules that include
both an amino group and a carboxyl group?
a. Alcohols
b. Proteins
c. Carbohydrates
d. Lipids
21.Two side groups which are characteristic of all amino acids
are
a. –OH and –COOH
b. –CH3 and –OH
c. –NH2 and –COOH
d. –NH2 and –CH2OH
22. What occurs when a peptide bond forms between two
amino acids?
a. Oxygen is released
b. Water is released
c. Oxygen is added
d. Water is added
23.Enzymes influence chemical reactions in living systems by
a. Providing the substrate required for the
reactions to occur
b. Combining with excess hydrogen to form gaseous
wastes
c. Affecting the rate at which the reactions occur
d. Absorbing water release when polymers are
formed
24. Which group of organic compounds includes the enzymes?
a. Proteins
b. Carbohydrates
c. Sugars
d. Starches
25. Any substance that is acted upon by an enzyme is called
a. Coenzyme
b. Vitamin
c. Substrate
d. Polypepetide
26. An enzyme that hydrolyzes starch usually will not act upon
sucrose. This fact is an indication that enzymes are
a.
b.
c.
d.
specific
synthetic
hydrolytic
catalytic
Base your answers to questions 27 through 29 on the diagram
below of an enzyme-controlled process which occurs in humans.
27. The process represented by the diagram is known as
a. photosynthesis
b. hydrolysis
c. dehydration synthesis
d. aerobic respiration
28. The enzyme is represented by figure
a.
b.
c.
d.
A
B
C
D
29. If figure B represents a disaccharide, figure D must
represent a molecule of
a. A polysaccharide
b. A fatty acid
c. An amino acid
d. A simple sugar
30. At what point on the graph shown below can the rate of
enzyme activity be increased by increasing the
concentration of substrate molecules?
a. 1
b. 2
c. 3
d. 4