Bio 201 - Chapter 4

Classifying molecules by their functional groups - carboxylic acid

-COOH; acts as an acid

Classifying molecules by their functional groups - amine

-NH2; acts as a base

Classifying molecules by their functional groups - organic phosphate

-OPO3(2-); contributes negative charge

Classifying molecules by their functional groups - thiol

-SH; forms disulfide bonds

The maximum number of hydrogen atoms in an alkane with six carbons is ________.

14

How many hydrogen atoms can be attached to carbon A?

3

Carbon's atomic number is 6. This means that it has __________ electrons. After completing the first energy level, carbon has __________ valence electrons and can form __________ bonds.

6; 4; 4

Which of the functional groups shown in the figure is present in hexanol but not in hexane?

A

Hydrolysis of ADP produces which of the following products?

AMP + Pi + energy

When three phosphate groups are covalently attached to adenosine, __________ is formed.

ATP

What is ATP's importance in the cell?

ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.

Identify the asymmetric carbon in this molecule.

B

Which molecule shown can be a result of mercaptoethanol reduction of a disulfide bridge?

B

Which molecule shown has a carbonyl functional group in the form of a ketone?

B

Which of the molecules in the figure above has an asymmetric carbon?

B

Which of the following is found in all amino acids?

Both -COOH and -NH2

Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a double bond in its carbon skeleton?

C2H4

Classifying molecules by their functional groups - aldehyde

C=O; may be a structural isomer of a ketone

Which element is always associated with organic chemistry?

Carbon

Which of the following unique feature of carbon allows it to support life on Earth?

Carbon can form a variety of bonds in nature.

What are the six most important chemical elements of life?

Carbon, nitrogen, oxygen, hydrogen, phosphate, and sulfur

All of the following statements accurately describe isomers

Geometric and Optical isomerism are two types of stereoisomerism; Isomers differ in both physical and chemical properties; Isomers have same molecular formula

Which of the following are properties of hydrocarbons?

Hydrophobic, nonpolar, and a good source of stored energy

Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, which of the following statements best describe a hydrocarbon chain with the same number of carbon atoms but with one or more double bonds?

It will be more constrained in structure.

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; what are enantiomers?

Molecules that are mirror images of each other.

Classifying molecules by their functional groups - alcohol

O-H; is polar and makes compounds more soluble in water

Pharmaceutical companies are selling close to $200 billion worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?

One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic.

L-dopa is used to treat _____.

Parkinson's disease

Which of the following molecules is a weak acid?

R-COOH

Which of the following molecules is a weak base?

R-NH2

Which functional group is not present in this molecule?

Sulfhydryl

What is the possible explanation for the presence of the harmful enantiomer?

The body must have an enzyme that is able to convert the beneficial thalidomide enantiomer into the harmful enantiomer.

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In which of the following ways do these molecules differ from each other?

They have different functional groups attached to the same carbon skeleton.

The carbon atom is tetravalent; this means that __________.

a carbon atom can complete its valence shell by forming four covalent bonds

Stanley Miller's experiments were significant because he demonstrated that __________.

a variety of simple organic compounds could be spontaneously synthesized from components in Earth's primitive atmosphere

In Miller's 1953 laboratory experiment, __________.

abiotic compounds cycled through the apparatus and were sampled for organic compounds

Choose the pair of terms that completes this sentence about functional groups in organic chemistry: Carboxyl is to __________ as __________ is to base.

acid; amino

Although the structures of the functional groups that are most important to life vary, they share one thing in common: They __________.

all help give each biological molecule its unique properties

Which chemical group is most likely to be responsible for an organic molecule behaving as a base?

amino

Enantiomers are molecules that _____.

are mirror images

Which carbon is asymmetric?

b

Molecules that contain only carbon and hydrogen are __________.

called hydrocarbons

Which of the following functional groups gives amino acids their acidic character?

carboxyl

Which two functional groups are always found in amino acids?

carboxyl and amino groups

The chemical group that acts as an acid is the __________.

carboxyl group (-COOH)

When a double bond joins two carbon atoms, __________ can form.

cis-trans isomers

A carbon atom is most likely to form what kind of bond(s) with other atoms?

covalent

Cis-trans isomers (geometric isomers) are molecules that _____.

differ in the arrangement of their atoms about a double bond

Which of the following explains why the valency of carbon is 4 even though it has 6 electrons?

has 2 electrons in its first shell and 4 in the second shell

An atom of iron has the atomic number 26. This means that

it has 26 protons and 26 electrons.

Which statement is true about the following molecule?

it is not an isomer

ATP is necessary for life because ________.

it is the principle energy carrying molecule in a cell

The carbon skeleton can vary in all of the following except __________.

lacking hydrogen atoms

In the pharmaceutical industry, two enantiomers of a drug __________.

may not be equally effective

Which of the following functional groups is hydrophobic in nature?

methyl

The chemical group that is involved in regulating DNA is the __________.

methyl group (-CH3)

Enantiomers are __________.

mirror-image isomers of a molecule

What kind of effect does R-dopa have on Parkinson's disease?

none

Inorganic carbon such as CO2 differs from organic carbon because __________.

organic carbon always has a hydrogen atom covalently attached to it

An atom has four electrons in its valence shell. What type(s) of covalent bonds is it capable of forming with oxygen?

single and double bonds

Choose the term that correctly describes the relationship between these two sugar molecules:

structural isomers

The two molecules shown in the figures are best described as ________.

structural isomers

The chemical group that helps stabilize protein structure is the __________.

sulfhydryl group (-SH)

Which of the following characteristics is responsible for the complexity and variety of organic molecules?

the chemical versatility of carbon atoms

Which of the following characteristics of an atom determines the number and kind of bonds it can form?

the number of particles in its valence shell

Structural isomers have __________.

the same molecular formula but different covalent arrangements of their carbon skeletons

SiSi has 4 valence electrons, --- carbon. Therefore, silicon would be able to form --- chains, including branches that could act as skeletons for --- molecules. It would clearly do this much better than neon (with --- valence electrons) or aluminum (with --- valence electrons), both of which cannot form branched molecules.

the same number as; long; larger; no; three

Organic chemistry is currently defined as

the study of carbon compounds.

What is the relationship between the following two molecules?

they are geometrical isomers

Chemical groups are significant because __________.

they contribute to the molecular shape of a molecule and its unique properties

Biologically important chemical groups include all of the following except __________.

water (includes hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, phosphate, methyl groups)