BIO 111 chapter 4
How many electron pairs does carbon share to complete its valence shell?
4
Which functional group shown above is characteristic of alcohols?
A
Which molecule shown above can function as a base?
A
Which molecule shown above contains an amino functional group, but is NOT an amino acid?
A
Which molecule shown above has a carbonyl functional group in the form of an aldehyde?
A
Which molecules shown above contain a carbonyl group?
A and B
Which molecule shown above can increase the concentration of hydrogen ions in a solution and is, therefore, an organic acid?
B
Which molecule shown above has a carbonyl functional group in the form of a ketone?
B
Which molecule shown above is a thiol?
B
Which of the groups above is a carboxyl functional group?
B
Which of the groups above is an acidic functional group that can dissociate and release H+ into a solution?
B
Which of the structures illustrated above is an impossible covalently bonded molecule?
B
Which functional group(s) shown above is (are) present in all amino acids?
B and C
Which molecule shown above can increase the concentration of hydrogen ions in a solution and is, therefore, an organic acid?
C
Which molecule shown above contains a carboxyl group?
C
Which of the groups above is a basic functional group that can accept H+ and become positively charged?
C
Which molecule(s) shown above is (are) ionized in a cell?
C and D
Which of the following molecules is polar?
C3H7OH and C2H5COOH are both polar molecules.
Which of the pairs of molecular structures shown below do NOT depict enantiomers (enantiomeric forms) of the same molecule?
CO2H<H-H-NH2 & CO2H<H2N-H-H
Which molecule shown above contains a functional group that cells use to transfer energy between organic molecules?
D
Which molecule shown above would have a positive charge in a cell?
D
Which of the groups shown above is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules?
D
Why is carbon so important in biology?
It can form a variety of carbon skeletons and host functional groups.
Which of the following is true of carbon?
It can form both polar and nonpolar bonds.
Why are hydrocarbons insoluble in water?
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.
Which of the following statements correctly describes cis-trans isomers?
They have variations in arrangement around a double bond.
Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that _____.
are mirror images of each other
Thalidomide and L-dopa, shown below, are examples of pharmaceutical drugs that occur as enantiomers, or molecules that _____.
are mirror images of one another
Which of the following is a FALSE statement concerning amino groups? Amino groups _____.
are nonpolar
The figure above shows the structures of glucose and fructose. These two molecules differ in the _____.
arrangement of carbon, hydrogen, and oxygen atoms
A hydrocarbon skeleton is covalently bonded to an amino group at one end and a carboxyl group at the other end. When placed in water this molecule would function _____.
as an acid and a base
Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms, but with one or more double bonds, will _____.
be more constrained in structure
Which of the pairs of molecular structures shown below depict enantiomers (enantiomeric forms) of the same molecule?
c) CO2H<H-CH3-CH3 & CO2H<H3C-CH3-H
Which of the following illustrations is NOT a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.
c) c-c=c-c
The element present in all organic molecules is _____.
carbon
Amino acids are acids because they always possess which functional group?
carboxyl
What is the name of the functional group shown in the figure below?
carboxyl
Which chemical group can act as an acid?
carboxyl
Which of the functional groups below acts most like an acid in water?
carboxyl
Which two functional groups are always found in amino acids?
carboxyl and amino groups
The two molecules shown in the figure below are best described as _____.
cis-trans isomers
A carbon atom is most likely to form what kind of bond(s) with other atoms?
covalent
Organic molecules with only hydrogens and five carbon atoms cannot _____.
form enantiomers
Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol _____.
have different functional groups attached to the same carbon skeleton
The experimental approach taken in current biological investigations presumes that _____.
living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena
In which of the structures illustrated above are the atoms bonded by ionic bonds?
none of the structures
Stanley Miller's 1953 experiments supported the hypothesis that _____.
organic molecules can be synthesized abiotically under conditions that may have existed on early Earth
A compound contains hydroxyl groups as its predominant functional group. Therefore, this compound _____.
should dissolve in water
When Stanley Miller applied heat and electrical sparks to a mixture of simple inorganic compounds such as methane, hydrogen gas, ammonia, and water vapor, what compounds were produced?
simple organic compounds, amino acids, and hydrocarbons
The figure above shows the structures of glucose and fructose. These two molecules are _____.
structural isomers
The two molecules shown in the figure below are best described as _____.
structural isomers
The complexity and variety of organic molecules is due to _____.
the chemical versatility of carbon atoms
What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration?
the presence or absence of double bonds between the carbon atom and other atoms
Differences among organisms are caused by differences in the _____.
types and relative amounts of organic molecules synthesized by each organism
