AP Biology - Unit 1 Exam

Nonpolar

Nonpolar

Equal sharing of electrons

Polar

Unequal sharing of electrons

Hydrogen Bond

Attraction between a slightly positive Hydrogen atom and a slightly negative Oxygen atom. Causes most properties of water.

Polar Covalent Bond

A covalent bond between atoms that differ in electronegativity.

Polar Molecule

A molecule with an uneven distribution of charges in different regions of the molecule.

Adhesion

Attraction between two different molecules.

Cohesion

Attraction between like molecules.

Specific Heat

The amount of heat that must be absorbed or lost for 1g of a substance to change by 1 degree Celsius.

Organic Molecules

Carbohydrates, Lipids, Nucleic Acids, Amino Acids

Macromolecule

A giant molecule formed by the joining of smaller molecules, usually by a dehydration reaction.

Monomer

A subunit that serves as a building block of a polymer.

Polymer

A long molecule consisting of many similar or identical monomers linked together by covalent bonds.

Dehydration Reaction

When two molecules are bonded to each other with the loss of a water molecule.

Hydrolysis

Essentially the reverse of a dehydration reaction. Breaks the bond between monomers by adding a water molecule. Also called digestion.

Carbohydrates

Consist of Carbon, Hydrogen, and Oxygen. Hydrogen to Oxygen ratio is always 2 to 1. Source of energy for most living organisms. There are three classes of carbohydrates: monosaccharides, disaccharides, and polysaccharides.

Monosaccharides

Have a chemical formula of C6H12O6. They are the simplest sugar and carbohydrate.

Disaccharides

Have a chemical formula of C16H22O11. They consist of two monosaccharides minus a water molecule, because of dehydration synthesis.

Polysaccharides

Macromolecules, polymers of carbohydrates. They form as monosaccharides and are joined together by dehydration reactions.

Lipids

A diverse class of organic compounds that includes fats, oils, waxes, and steroids. Made of fatty acids, which are made of Carbon, Hydrogen, and Oxygen.. Used for long term energy storage. Work as chemical messengers and a large component of cell membranes. They are all hydrophobic.

Fatty Acids

A hydrocarbon chain with a carboxyl group at one end. Fatty acids exist in two varieties, saturated and unsaturated.

Steroids

Lipids that do not have the same general structure as other lipids. Characterized by a carbon skeleton consisting of four rings with various functional groups attached.

Nucleic Acid

Phosphate group, 5 carbon sugar, nitrogenous base. Store and transmit genetic information.

Proteins

Made of amino acids.A protein itself is an expressed gene and make tissue like muscle and bone. Crucial in transport through your body, immune system, cell reaction and processes, and send chemical signals.

Polypeptides

A polymer (chain) of many amino acids linked together by peptide bonds. NOT the same as a protein! Think of it as the strand of yarn that goes into the sweater.

Primary Structure

The specific linear sequence of amino acids, like the order of letters in a word.

Secondary Structure

The localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between peptide linkages (not the side chains!).

Tertiary Structure

The overall shape of a protein molecule due to interactions of amino acid side chains, including hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges.

Quaternary Structure

The particular shape of a complex, aggregate protein, defined by the characteristic three-dimensional arrangement of its constituent subunits, each a polypeptide.

How many amino acids are there?

20

How do hydrogen bonds affect the structure of the protein?

They cause the folds and coils that appear at regular angles.

Hydrophobic Interaction

The molecules that don't want to touch the water because they are nonpolar so they end up in clusters at the core of the protein. They are much weaker than covalent bonds.

Exergonic Reaction

A spontaneous chemical reaction in which there is a net release of free energy.

Endergonic Reaction

A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings.

Metabolism

All of the chemical reactions that occur within an organism.

ATP

Releases energy when you remove a phosphate. Becomes ADP. Requires energy to add phosphate.

Catabolic

Breaking down molecules and releasing energy

Anabolic

Building Molecules and consuming energy

Capillary Action

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Heat of vaporization

The quantity of heat a liquid must absorb for 1g of it to be converted from a liquid into a gas. Water has a high heat of vaporization as a result of its strong hydrogen bonds.