BSC2010 Final Questions with Answers (100%
Correct Answers)
The element present in all organic molecules is___. Answer: Carbon
The large diversity of shapes of biological molecules is possible because of the
extensive presence of ____ in the molecules. Answer: Carbon
- With four electrons to share, carbon-based molecules can be multi branching
and 3D variable.
How many electron pairs does carbon share in order to complete its valence
shell. Answer: 4
Why are hydrocarbons insoluble in water? Answer: The majority of their bonds
are non-polar covalent carbon-to-hydrogen linkages.
Which of the following is a hydrocarbon? Answer: C3H8
-This is a typical hydrocarbon with single covalent bonds; the number of
hydrogen atoms is equal to two times the number of carbon atoms plus 2.
Molecules that have the same chemical formula (same numbers of each atom)
but different 3D shapes are called_____. Answer: isomers
-Isomers of carbon compounds can arise in several different ways.
How do isomers differ from one another? Answer: Isomers differ in the
arrangement or bonding of atoms.
-Isomers may differ in the covalent arrangements of their atoms or the position
of double bonds within the molecule and thus have different chemical
properties.
Which of the following best describes cis-trans isomers? Answer: They differ in
their spatial arrangement around inflexible double bonds.
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-Cis-trans isomers maintain the same covalent partnerships, but the atoms may
be arranged differently.
Variations in the reactive properties of different organic molecules are most
closely associated with_____. Answer: The presence or absence of functional
groups.
-Functional groups are the most common participants in chemical reactions.
Citric acid makes lemons taste sour. Which of the following is a functional
group that would cause a molecule such as citric acid to be acidic? Answer:
Carboxyl
-The carboxyl group can release a hydrogen ion when in solution.
Which statement about a methyl functional group is correct? Answer: A methyl
group consists of a carbon bonded to three hydrogen atoms.
-A methyl group consists of a carbon covalently bonded to three hydrogen
atoms.
Most organic compounds contain carbon and ____. Answer: Hydrogen
-In fact, some argue that carbon dioxide should not be considered an organic
molecule because it does not contain hydrogen.
Organic chemistry is currently defined as Answer: The study of carbon
compounds.
Vitalism gave way to mechanism, the view that____. Answer: Physical and
chemical laws govern living systems.
-Living things are subject to physical and chemical laws. They so not exist
outside of them.
What are the six most important chemical elements of life? Answer: Carbon,
nitrogen, oxygen, hydrogen, phosphate, sulfur.
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-All of these elements are capable of forming strong covalent bonds, important
in building large, complex molecules.
Which of the following is an organic molecule? Answer: CH4
-Compounds containing carbon are said to be organic.
Which statement helps most to explain why life is based on carbon
compounds? Answer: C-C bonds are as strong as C-O bonds.
-C is the only element that bonds with its own kind about as strongly as it
bonds with other elements. That, plus C's ability to form 4 bonds, makes it
possible to build stable, varied biological molecules.
L-dopa is used to treat____. Answer: Parkinson's disease
-People with Parkinson's disease lack dopamine.
What kind of effect does R-dopa have on Parkinson's disease? Answer: None
-R-dopa has no effect on Parkinson's disease.
Enantiomers are molecules that_____. Answer: Are mirror images.
Geometric isomers are molecules that _____. Answer: Differ in the
arrangement of their atoms about a double bond.
A molecule has one carbon-carbon double bond and four monovalent atoms or
group. How many different cis-trans isomers exist for this molecule? Answer: 2
-Only 2 cis-trans isomers exist.
Identify the functional groups. Answer: Amino and carboxyl are functional
groups.
Which of the following functional groups increases the solubility of organic
compounds in water? Answer: -COH
-OH