BIO 251 Chapter 2 Flashcards

Flashcards covering key vocabulary from BIO 251 Chapter 2, based on lecture notes.

Matter

The stuff of the universe that has mass and occupies space.

Energy

The capacity to do work, or to put matter into motion.

Potential Energy

Energy that is inactive or stored.

Kinetic Energy

Energy in action.

Atom

The smallest particle of an element that has the properties of that element.

Proton

Positive charge, found in the nucleus.

Neutron

Neutral charge, found in the nucleus.

Electron

Negative charge, orbits the nucleus.

Atomic Number

The number of protons in an atom's nucleus.

Atomic Mass

The sum of the masses of protons and neutrons in the nucleus.

Isotope

Structural variations of atoms with the same number of protons but different numbers of neutrons.

Ionic Bond

Attractive force between ions of opposite charge.

Covalent Bond

Bond formed by the sharing of electrons.

Hydrogen Bond

Weak bond formed between a hydrogen atom and an electronegative atom.

Synthesis Reaction

A reaction where smaller particles are bonded together to form larger, more complex molecules.

Decomposition Reaction

A reaction where bonds are broken in larger molecules, resulting in smaller, less complex molecules.

Exchange Reaction

Reactions where bonds are both made and broken.

Solution

A homogeneous mixture of components that may be gases, liquids, or solids.

Colloid

A mixture in which solute particles are larger than in a solution and scatter light, but do not settle out.

Suspension

A mixture in which solute particles are very large, settle out, and may scatter light.

Covalent Bond

Sharing of pairs of electrons; may be polar or nonpolar.

Ionic Bond

The attraction between two oppositely charged ions.

Hydrogen Bond

The attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom with a slightly negative charge.

pH Scale

A scale used to measure the relative acidity or alkalinity of a solution.

Dehydration Synthesis

A chemical reaction in which monomers are joined by removing a water molecule.

Hydrolysis

A chemical reaction in which monomers are released by the addition of a water molecule.

Monosaccharides

Monomers of carbohydrates; examples include glucose, fructose, and galactose.

Disaccharides

Consist of two linked monosaccharides; examples include sucrose, maltose, and lactose.

Polysaccharides

Long chains (polymers) of linked monosaccharides; examples include glycogen, starch, and cellulose.

Triglycerides

Lipids composed of glycerol and three fatty acids; major form of stored energy in the body.

Saturated Fat

A fat with no double bonds between carbon atoms; molecules are packed closely together at room temperature.

Unsaturated Fat

A fat with one or more double bonds between carbon atoms, causing kinks in the fatty acid chains; molecules cannot pack together closely enough to solidify at room temperature.

Phospholipids

Chief components of cell membranes; help transport lipids in blood.

Cholesterol

A lipid that is a component of cell membranes and a starting molecule for the synthesis of all body steroids.

Structural Proteins

These proteins provide mechanical support, such as collagen in connective tissue.

Enzyme Proteins

These proteins catalyze biochemical reactions, such as disaccharidases and proteases.

Transport Proteins

These proteins move substances in blood or across plasma membranes, such as hemoglobin.

Contractile Proteins

These proteins are responsible for movement, such as actin and myosin in muscle cells.

Communication Proteins

These proteins transmit signals between cells, such as hormones or receptors.

Defensive Proteins

These proteins protect against disease, such as antibodies.

Primary Structure (Proteins)

The sequence of amino acids forming the polypeptide chain.

Secondary Structure (Proteins)

The primary chain forms spirals and sheets held together by hydrogen bonds.

Tertiary Structure (Proteins)

Superimposed on secondary structure; the chain is folded up to form a compact globular molecule.

Quaternary Structure (Proteins)

Two or more polypeptide chains combine to form a functional protein.