AP Biology Unit 1: Chemistry of Life Flashcards

Vocabulary flashcards covering key terms and definitions for AP Biology Unit 1: Chemistry of Life.

Polar Molecule

A molecule with an uneven distribution of charge, resulting in opposite ends having opposite charges.

Hydrophilic

Describes polar molecules or substances that have an affinity for water and dissolve in it.

Hydrophobic

Describes nonpolar molecules that do not dissolve in water and repel aqueous solutions.

Cohesion

Water's ability to stick to other water molecules through hydrogen bonding, which is responsible for water's high surface tension.

Adhesion

Water's ability to stick to other molecules and surfaces.

Specific Heat

The amount of heat absorbed or lost to change temperature; water has a high specific heat, allowing it to absorb great amounts of energy without increasing temperature at the same rate.

Molarity

The number of moles of solute per liter of solution, used as a measure of solute concentration in solutions.

Buffer

An acid-base pair that combines reversibly with hydrogen ions, allowing a solution to resist changes in pH.

Organic Compounds

Chemical compounds that contain carbon (and usually hydrogen) that compose living things.

Isomers

Alternate arrangements of molecules that share the same chemical formula but have different arrangements of atoms and different properties.

Dehydration Synthesis

A chemical reaction that joins monomers together by removing a hydrogen atom from one monomer and a hydroxyl group from another, creating a new covalent bond and releasing a water molecule.

Hydrolysis

A chemical process that separates monomers by adding a molecule of water to break a covalent bond.

Primary Structure

The specific sequence order of amino acids in a polypeptide chain.

Secondary Structure

Local structural units of a protein, such as $\alpha$-helices and $\beta$-pleated sheets, formed by hydrogen bonding within the polypeptide backbone.

Tertiary Structure

The overall three-dimensional shape of a single polypeptide chain resulting from interactions among variable R-groups.

Quaternary Structure

The protein structure that arises from interactions and binding between multiple polypeptide subunits.

Saturated Fatty Acid

A fatty acid possessing only single bonds in its hydrocarbon chain, giving it a linear structure.

Unsaturated Fatty Acid

A fatty acid possessing at least one double bond in its hydrocarbon chain, which creates a kinked structure.

Phospholipid

A lipid composed of a glycerol molecule, two nonpolar hydrophobic fatty acid tails, and a polar hydrophilic phosphate head.

Steroids

Nonpolar lipid molecules consisting of four fused carbon rings.

Glycogen

A branched storage polysaccharide composed of glucose monomers used by animals.

Starch

A coiled storage polysaccharide composed of glucose monomers used by plants.

Cellulose

A linear structural carbohydrate composed of glucose monomers used in plant cell walls.