Biochemistry Flashcards

Vocabulary flashcards for Biochemistry review.

Atom

The smallest unit of an element that maintains the chemical properties of the element.

Proton

Subatomic particles that carry a positive charge and are located in the nucleus of an atom.

Neutron

Subatomic particles that carry no charge (are neutral) and are located in the nucleus of an atom.

Electrons

Subatomic particles that carry a negative charge and are located in the electron cloud.

Molecule

Two or more atoms that are covalently bonded together.

Valence Shell

The outermost electron shell of an atom.

Valence Electrons

The electrons located in the outermost electron shell (valence shell) of an atom; these are the most important electrons for chemical bonds and the chemical properties of an element or molecule.

Covalent Bond

A type of intramolecular bond resulting from the sharing of valence electrons between atoms.

Polar Molecule

A molecule that carries a slight electrical charge at opposite poles.

Non-polar Molecule

A molecule that does not have an electrical charge.

Electronegativity

Refers to an atom's desire to acquire electrons. Oxygen and Nitrogen are the most biologically important molecules with a high electronegativity.

Ionic Bond

A chemical bond that forms between metal and non-metal atoms when metal atoms lose electrons and non-metal atoms gain electrons.

Cations

Ions which possess a positive charge because they have more protons than electrons; like metal atoms.

Anions

Ions which possess a negative charge because they have more electrons than protons; like non-metal atoms.

Hydrogen Bond

Weak intermolecular attractions that occur between polar molecules.

Van der Waals Interactions (London Dispersion Forces)

Temporary intermolecular attractions created when electrons clump on one side of an atom, making that side temporarily negative and the other side positive.

Cohesion

The property of water molecules sticking to each other due to its polarity.

Adhesion

The property of water molecules sticking to other polar molecules due to its polarity.

Surface Tension

The property of water that makes it difficult to break its surface due to cohesive forces between the molecules.

Specific Heat

The amount of heat needed to change the temperature of 1 gram of a substance by 1 degree Celsius.

Heat of Vaporization

The amount of heat needed to convert a liquid to a gas.

Polymers

Large molecules formed by combining/bonding individual units called monomers.

Monomers

Individual units that, when combined, form larger molecules called polymers. The monomers are linked together by covalent bonds.

Dehydration Synthesis (Condensation)

Reactions during which monomers are covalently bonded together, releasing water as a byproduct.

Hydrolysis

Reactions in which macromolecules are broken apart into individual monomers, using water as a reactant.

Monosaccharides

The monomers or 'building blocks' of carbohydrates. Examples include glucose, fructose, and galactose.

Polysaccharides

Polymers formed by the bonding together of several monosaccharides. Examples include starch, glycogen, cellulose, and chitin.

Lipids

Macromolecules that include fats, oils, waxes, and steroids. Most lipids are hydrophobic and contain little oxygen.

Fatty Acid

A long chain of carbon and hydrogen atoms; a main part of a lipid.

Glycerol

A 3-carbon alcohol molecule that helps hold the fatty acids together in a lipid.

Ester Linkage

A covalent bond used by lipids to hold the fatty acids and glycerol together.

Triglycerides

Basic fats or oils composed of three fatty acids and glycerol.

Saturated Fats

Fats with no carbon-carbon double bonds in their fatty acid chains; they are solids at room temperature and are usually associated with animals.

Unsaturated Fats

Fats that contain some carbon-carbon double bonds in their fatty acid chains; they tend to be liquids at room temperature and are usually associated with plants.

Phospholipids

Lipids with a phosphate portion that is hydrophilic and fatty acid chains that are hydrophobic; important for building cell and organelle membranes.

Amphipathic

Having both polar and nonpolar sides, as is the case with phospholipids.

Proteins

Large macromolecules composed of monomers called amino acids.

Amino Acids

The monomers or 'building blocks' of proteins; there are 20 different amino acids used by living things to make proteins.

Peptide Bond

A covalent bond that links individual amino acids together.

Dipeptide

Two amino acids bonded together.

Polypeptide Chain

A structure formed when more than two amino acids are bonded together.

Amino Terminus (N-terminus)

The end of a polypeptide chain with a free amino group.

Carboxyl Terminus (C-terminus)

The end of a polypeptide chain with a free carboxyl group.

Primary Structure (1')

The sequence of bonded amino acids in a protein.

Secondary Structure (2')

The shape of specific sections of each polypeptide chain; examples include alpha helix and beta pleated sheet.

Tertiary Structure (3')

The overall shape of each individual polypeptide chain.

Quaternary Structure (4')

The overall structure of a protein when two or more polypeptides are woven together.

Nucleic Acids

Function to store genetic information and/or to store and transfer energy. Common nucleic acids found living organisms include DNA, RNA, ATP, cAMP, NADH, and NADPH.

Nucleotides

The monomers of nucleic acids, consisting of a 5-carbon sugar bonded to a phosphate group and a nitrogenous base.

DNA (Deoxyribonucleic Acid)

A double-stranded nucleic acid with deoxyribose as its 5-carbon sugar; it codes for proteins.

RNA (Ribo Nucleic Acid)

A single-stranded nucleic acid with ribose as its 5-carbon sugar.