Carbon & the Molecular Diversity of Life - Flashcards

A set of Q&A flashcards covering key concepts from the lecture notes on carbon, organic chemistry, isomers, functional groups, and ATP.

What distinguishes organic molecules from inorganic molecules?

Organic molecules contain carbon (and usually hydrogen), whereas inorganic molecules do not contain carbon (carbon dioxide is considered inorganic).

What are the major elements that make up organic molecules?

Hydrogen, Oxygen, Nitrogen, and Carbon.

How many valence electrons does carbon have in its outer shell, and how many bonds can it form?

Carbon has 4 valence electrons and can form 4 covalent bonds.

Why is carbon described as tetravalent?

Because its outer shell allows it to form four bonds in four directions.

What is the bond angle in a carbon tetrahedral geometry?

109.5 degrees.

When carbon forms a double bond, how are the bonds arranged?

All bonds lie in the same plane.

What is a hydrocarbon?

A compound that contains only carbon and hydrogen.

What do the suffixes -ane, -ene, and -yne indicate in hydrocarbons?

-ane indicates single bonds, -ene indicates double bonds, and -yne indicates triple bonds between carbon atoms.

What is the difference between aliphatic and aromatic hydrocarbons?

Aliphatic hydrocarbons are linear chains, while aromatic hydrocarbons form closed rings with alternating single and double bonds.

What are fats composed of, according to the notes?

Large hydrocarbon chains attached to a non-hydrocarbon component.

What is a carbon skeleton?

The chain of carbon atoms in a compound’s structure; different lengths/arrangements yield different compounds.

What are isomers?

Compounds with the same number of atoms of the same elements but different arrangements of atoms or bonds (structural isomers, cis-trans isomers, enantiomers).

What characterizes structural isomers?

They differ in the placement of covalent bonds and can have different properties.

What are cis-trans isomers?

Isomers that have the same covalent bonds but differ in the arrangement around a double bond; cis = same side, trans = opposite side.

What are enantiomers?

Isomers that are mirror images of each other due to a carbon bonded to four different atoms.

What is chirality?

The property of an object that cannot be superimposed on its mirror image; chiral vs. achiral.

How do the number and arrangement of chemical groups affect molecular function?

They give molecules unique properties and determine how they interact in the body.

List the seven most important functional groups in biological processes.

Hydroxyl (-OH), Carbonyl (>C=O), Carboxyl (-COOH), Amino (-NH2), Sulfhydryl (-SH), Phosphate (-OPO3^2−), Methyl (-CH3).

What is the hydroxyl group and its key property?

-OH; it is polar due to the electronegative oxygen and forms hydrogen bonds with water (example: ethanol).

What is the carbonyl group and what types of compounds contain it?

C=O; found in ketones and aldehydes; sugars with ketone groups are ketoses and those with aldehydes are aldoses.

What is the carboxyl group and its typical behavior?

-COOH; acts as an acid; examples include acetic acid; often called carboxylic acid (carboxylate in ionized form).

What is the amino group and its typical role in biology?

-NH2; acts as a base; example in glycine; found in amino groups of amino acids.

What is the sulfhydryl group and what is its significance in proteins?

-SH; two sulfhydryl groups can form cross-links that stabilize protein structure (thiol).

What is the phosphate group and its general role in biology?

-OPO3^2−; contributes negative charge and participates in reactions with water, often releasing energy when hydrolyzed (as in organic phosphates like glycerol phosphate).

What is ATP?

Adenosine triphosphate; an adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed.

What happens when ATP hydrolyzes to ADP?

One phosphate group is split off, forming ADP and releasing energy that can be used by the cell.