Carbon and the Molecular Diversity of Life - Chapter 4 Flashcards
Organic chemistry is currently defined as ____
the study of carbon compounds
Which chemical group is most likely responsible for an organic molecule behaving as a base?
a. hydroxyl
b. carbonyl
c. phosphate
d. carboxyl
e. amino
e. amino
Which of the following hydrocarbons has a double bond in its carbon skeleton?
a. CH4
b. C3H8
c. C2H6
d. C2H4
e. C2H2
d. C2H4
What action could produce a carbonyl group?
a. the addition of a hydroxyl to a phosphate
b. the replacement of the -OH of a carboxyl group with hydrogen
c. the replacement of the nitrogen of an amine with oxygen
d. the addition of a thiol to a hydroxyl
e. the addition of a sulfhydryl to a carboxyl
b. the replacement of the -OH of a carboxyl group with hydrogen
Six most important chemical elements of life?
Carbon, nitrogen, oxygen, hydrogen, phosphate, sulfur
Stanley Miller’s experiments were significant because he demonstrated that
a. a variety of simple organic compounds could be spontaneously synthesized from components in Earth’s primitive atmosphere
b. organic molecules can be synthesized only by living organisms
c. the behavior of any molecule containing a carbon atom was fundamentally the same
d. lightning discharges could produce the molecules previously presumed to have originated in volcanic outgassings
a. a variety of simple organic compounds could be spontaneously synthesized from components in Earth’s primitive atmosphere
What is the 3D shape created by hybrid orbitals that are formed when a carbon atom is covalently bonded with four other atoms?
a. a tetrahedron with carbon in the center
b. a flat sheet with carbon in the center
c. a triangle with carbon in the center
d. All of the responses are possible
a. a tetrahedron with carbon in the center
What are enantiomers?
isomers that are mirror images of each other
Why do enantiomers differ in shape?
due to presence of an asymmetric carbon
How many valence electrons does carbon have?
4
Properties of hydrocarbons?
Hydrophobic, nonpolar, good source of stored energy (ex. fossil fuels and fats)
A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different cis-trans isomers exist for this molecule?
a. 2
b. 0
c. 4
d. 6
a. 2
Which of the following functional groups is present in all amino acids?
a. -NH2
b. -COH
c. -SH
d. -OH
a. -NH2
Which of these is found in all amino acids?
a. -OH
b. -COH
c. -COOH
d. both -COOH and -NH2
d. both -COOH and -NH2
Which of the following functional groups increases the solubility of organic compounds in water?
a. -OH
b. -COH
c. -COOH
d. All are correct.
d. All are correct.
What happens when phosphate groups are removed from carbon skeletons with water?
Formation of an inorganic phosphate, release of energy
Why can amino, hydroxyl, and carboxyl groups hydrogen bond with oxygen atoms on other functional groups?
Because they are all polar.
Functions of proteins?
communication, defense, structural support, movement
What do all proteins have in common?
All are polymers of amino acids
Explain the structure of amino groups.
alphacarbon in the middle, side chain and an amino group
What happens when amino groups are ionized in aqueous solutions?
The amino group becomes protonated. The carboxyl group donates hydrogen at neutral pH.
As pH decreases, what happens to protein?
Lower pH is due to a higher concentration of protons in solution. At a low enough pH, carboxyl groups can act as bases and give the protein a net neutral charge.
As pH increases, what happens to protein?
Higher pH is due to a lower concentration of protons in solution. Amino groups can lose protons and act as acids.
What is a residue?
the alternative name for a monomer when it’s part of a polymer
