EXAM II

Purines

Nitrogenous bases with 2 rings; includes Adenine (A) and Guanine (G).

Pyrimidines

Nitrogenous bases with 1 ring; includes Cytosine (C), Thymine (T) (DNA only), and Uracil (U) (RNA only).

Base Pairing

The pairing of nitrogenous bases in DNA; A–T pairs with 2 hydrogen bonds and G–C pairs with 3 hydrogen bonds.

Antiparallel Strands

DNA strands that run in opposite directions.

Denaturation of DNA

The breaking of hydrogen bonds in DNA, not affecting the phosphodiester backbone.

Nucleotide Composition

A nucleotide consists of a phosphate group, a sugar, and a nitrogenous base.

Macromolecule Monomer: Carbohydrate

Monomer is monosaccharide.

Macromolecule Polymer: Carbohydrate

Polymer is polysaccharide.

Bond in Carbohydrates

The bond linking monosaccharides in carbohydrates is glycosidic.

Polypeptide

Polymer of proteins, formed from amino acids.

Peptide Bond

The bond connecting amino acids in proteins.

Primary Structure of Proteins

The unique sequence of amino acids in a polypeptide.

Secondary Structure of Proteins

The folding or coiling of the polypeptide chain into α-helices or β-sheets.

Tertiary Structure of Proteins

The overall 3D shape of a protein due to interactions between R groups.

Enzyme Function

Enzymes lower activation energy and do not change depending on the reaction type.

Competitive Inhibitor

Inhibitor that binds to the active site of an enzyme.

Noncompetitive Inhibitor

Inhibitor that binds to a different site on an enzyme.

Feedback Inhibition

Process where a product inhibits an earlier step in the pathway.

Simple Diffusion

Movement from high to low concentration without protein or ATP.

Facilitated Diffusion

Movement from high to low concentration with the aid of protein, without ATP.

Active Transport

Movement from low to high concentration, requiring protein and ATP.

Atoms and Bonds: Protons

Protons determine the identity of an element.

Valence Electrons

Determined by the group number of an element.

Carbon Bonding

Carbon can form 4 covalent bonds.

High Specific Heat of Water

Property of water due to hydrogen bonding.

Cohesion

The tendency of water to stick to itself.

Adhesion

The tendency of water to stick to other surfaces.

Exergonic Reaction

A reaction that releases energy.

Endergonic Reaction

A reaction that requires energy.

Triglyceride

A type of lipid used for long-term energy storage.

Phospholipid

A lipid that forms the bilayer of cell membranes.

Glycolysis Products

Glycolysis produces pyruvate and ATP.

Mitochondria

Cell organelle that makes ATP.