AP Biology Chapter 4: Carbon Chemistry & Molecular Diversity

Flashcards covering key concepts of AP Biology Chapter 4 on carbon bonding, functional groups, and isomers.

What is organic chemistry?

The study of carbon compounds.

Why is carbon important in biology?

Carbon can form four covalent bonds with many different atoms, including other carbon atoms. This allows it to form diverse carbon skeletons and many different organic molecules.

How many valence electrons does carbon have?

4

What is tetravalence?

Carbon's ability to form four covalent bonds because it has four valence electrons available for bonding.

Why can carbon form chains, branches, and rings?

Carbon can bond to other carbon atoms, allowing carbon skeletons to have many different arrangements.

What is a carbon skeleton?

The arrangement or framework of carbon atoms that forms the backbone of an organic molecule.

What are hydrocarbons?

Organic molecules made only of carbon and hydrogen.

Why are hydrocarbons important?

They provide basic carbon-based frameworks that can be modified to form many organic molecules.

What is a functional group?

A specific group of atoms attached to a carbon skeleton that gives an organic molecule characteristic chemical properties.

What is the hydroxyl functional group?

$$\text{-OH}$$

What atoms make up a hydroxyl group?

1 oxygen and 1 hydrogen.

What type of compounds contain hydroxyl groups?

Alcohols.

What is an important property of the hydroxyl group?

It is polar and can form hydrogen bonds.

What is the carbonyl functional group?

$$\text{C=O}$$

What atoms make up a carbonyl group?

A carbon double-bonded to oxygen.

What two major types of compounds contain carbonyl groups?

Aldehydes and ketones.

What is an aldehyde?

A compound with a $\text{C=O}$ at the end of the carbon skeleton, where the carbonyl carbon is also bonded to H.

What is the structure of an aldehyde?

$$\text{R-C(=O)-H}$$

What is a ketone?

A compound with a $\text{C=O}$ within the carbon skeleton, where the carbonyl carbon is bonded to carbon-containing groups on both sides.

What is the structure of a ketone?

$$\text{R-C(=O)-R}$$

What does R represent in an organic chemistry structure?

The rest of the molecule or carbon-containing portion attached to the functional group.

How do you distinguish an aldehyde from a ketone?

An aldehyde has the carbonyl carbon bonded to H; a ketone has the carbonyl carbon bonded to carbon-containing groups on both sides.

What is the carboxyl functional group?

$$\text{-COOH}$$

What two functional groups are combined in a carboxyl group?

A carbonyl group and a hydroxyl group.

What property does a carboxyl group give an organic molecule?

Acidic properties.

What is the amino functional group?

$$\text{-NH}_2$$

What atoms are in an amino group?

1 nitrogen and 2 hydrogens.

What property does an amino group give an organic molecule?

Basic properties.

What is the sulfhydryl functional group?

$$\text{-SH}$$

What atoms make up a sulfhydryl group?

1 sulfur and 1 hydrogen.

What are compounds containing sulfhydryl groups called?

Thiols.

Why are sulfhydryl groups important in proteins?

They can form cross-links that help stabilize protein structure.

What is the phosphate functional group?

A group containing phosphorus (P) bonded to oxygen atoms.

How do you recognize a phosphate group?

Look for P bonded to oxygen atoms.

How many oxygen atoms are commonly represented in the phosphate group in this study guide?

4 oxygen atoms.

What is a methyl group?

$$\text{-CH}_3$$

What atoms make up a methyl group?

1 carbon and 3 hydrogens.

What functional group is $\text{-OH}$?

Hydroxyl.

What functional group is $\text{C=O}$?

Carbonyl.

What functional group is $\text{-COOH}$?

Carboxyl.

What functional group is $\text{-NH}_2$?

Amino.

What functional group is $\text{-SH}$?

Sulfhydryl.

What functional group is $\text{-CH}_3$?

Methyl.

What is the easiest way to recognize phosphate?

Look for P bonded to oxygen atoms.

Which functional group is associated with acidic properties?

Carboxyl ($\text{-COOH}$).

Which functional group is associated with basic properties?

Amino ($\text{-NH}_2$).

What are isomers?

Molecules that have the same molecular formula but different structures.

What are structural isomers?

Isomers with the same molecular formula but different covalent arrangements or connections of their atoms.

How do you remember structural isomers?

STRUCTURAL = the structure or connections change.

What are geometric (cis-trans) isomers?

Molecules with the same connections but different arrangements of groups around a double bond or ring.

What does cis mean?

Groups are on the same side.

What does trans mean?

Groups are on opposite sides.

How do you remember cis?

CIS = SAME SIDE.

How do you remember trans?

TRANS = ACROSS or OPPOSITE SIDES.

What are enantiomers?

Molecules that are nonsuperimposable mirror images of each other.

How do you remember enantiomers?

ENANTIOMER = MIRROR IMAGE.

Why can enantiomers behave differently in living organisms?

Their different three-dimensional shapes can cause them to interact differently with biological molecules.

What is an example of a molecule with enantiomers?

Lactic acid has two enantiomeric forms with different three-dimensional arrangements.

What is an isotope?

Atoms of the same element with different numbers of neutrons.

What stays the same in isotopes?

The number of protons.

What changes in isotopes?

The number of neutrons.

How do you remember isotope?

ISOTOPE = same element, different neutrons.

How do you remember isomer?

ISOMER = same molecular formula, different structure.

What is the difference between an isotope and an isomer?

Isotopes are atoms of the same element with different numbers of neutrons; isomers are molecules with the same molecular formula but different structures.

What is the difference between carbonyl and carboxyl?

Carbonyl is C=O; carboxyl is COOH, which contains both a carbonyl and a hydroxyl group.

What is the difference between hydroxyl and carboxyl?

Hydroxyl is -OH; carboxyl is -COOH.

What is the difference between amino and carboxyl?

Amino (-NH2) is associated with basic properties; carboxyl (-COOH) is associated with acidic properties.

What is the difference between methyl and amino?

Methyl is CH3; amino is NH2.

What is the difference between sulfhydryl and hydroxyl?

Sulfhydryl is SH and contains sulfur; hydroxyl is OH and contains oxygen.

What is the difference between structural, geometric, and enantiomer isomers?

Structural isomers have different atom connections; geometric isomers differ in group positions around a double bond or ring; enantiomers are nonsuperimposable mirror images.

What is the big picture of carbon chemistry?

Carbon's four covalent bonds allow diverse carbon skeletons; functional groups give molecules different chemical properties; different structures can produce isomers.