Biological Systems: Elements, Bonds, and Properties of Water

These flashcards encompass key vocabulary and concepts from biology related to living systems, especially focused on elements, chemical bonds, and the properties of water.

DNA

Deoxyribonucleic acid, the hereditary material in humans and almost all other organisms.

RNA

Ribonucleic acid, a molecule essential for various biological roles in coding, decoding, regulation, and expression of genes.

Protein

Large biological molecules, consisting of one or more chains of amino acids, essential for the structure, function, and regulation of the body’s cells, tissues, and organs.

Periodic Table

A tabular arrangement of the chemical elements, organized by their atomic number, electron configurations, and recurring chemical properties.

Element

A pure substance that cannot be broken down into simpler substances by chemical means.

Covalent Bond

A type of chemical bond where atoms share electrons to achieve stability.

Ionic Bond

A chemical bond formed through the electrical force between oppositely charged ions.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons.

Hydrogen Bond

A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.

Amphipathic Molecule

A molecule that has both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions.

Hydrophilic

A property of a substance that indicates its affinity for water; able to form hydrogen bonds with water.

Hydrophobic

A property of a substance that repels water; does not interact favorably with water.

Homeostasis

The ability of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.

Atomic Structure

The composition of an atom, consisting of protons, neutrons, and electrons.

Bond Strength

The measure of the energy required to break a bond.

Sodium Chloride

An ionic compound made up of sodium and chloride, commonly known as table salt.

Chemical Bond

A lasting attraction between atoms that enables the formation of chemical compounds.

Biomolecules

Molecules that are essential to life, including carbohydrates, lipids, nucleic acids, and proteins.

Carbohydrates

Organic compounds made up of carbon, hydrogen, and oxygen, important for energy storage.

Electron Shell

The area surrounding the atomic nucleus where electrons are likely to be found.

Potential Energy

Energy stored within an object, which can be converted into kinetic energy.

Stable Configuration

The arrangement of electrons and protons that results in a low-energy state of an atom or molecule.

Octet Rule

The principle that atoms tend to bond in such a way that they each have eight electrons in their valence shell.

Chemical Reaction

A process that leads to the transformation of one set of chemical substances to another.

Entropy

A measure of disorder or randomness in a system.

Biological Macromolecules

Large complex molecules essential for life, including carbohydrates, proteins, nucleic acids, and lipids.

Ion

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Anion

A negatively charged ion.

Cation

A positively charged ion.

Valence Electrons

Electrons that are found in the outermost shell of an atom and are involved in forming bonds.

Dissociation

The process in which molecules separate or break into smaller particles such as atoms or ions.

Chemical Equilibrium

A state in which reactants and products of a chemical reaction are present in concentrations that have no further tendency to change.

Polarity

The distribution of electrical charge over the atoms in a molecule.

Capillary Action

The ability of a liquid to flow in narrow spaces without the assistance of external forces.

Surface Tension

The property of the surface of a liquid that allows it to resist an external force.

Solubility

The ability of a substance (solute) to dissolve in a solvent.

Fatty Acids

Carboxylic acids with long aliphatic chains, which can be saturated or unsaturated.

Peptide Bond

The chemical bond formed between two amino acids.

Biochemical Reaction

A process that leads to the transformation of one set of biochemical substances (reactants) into another set (products).

Macromolecule

A large molecule often composed of smaller subunits (monomers), such as proteins and nucleic acids.

Functional Group

A specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule.

Endothermic Reaction

A reaction that absorbs energy from the surroundings.

Exothermic Reaction

A reaction that releases energy to the surroundings.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing any permanent chemical change.

Enzyme

A biological catalyst that accelerates chemical reactions in living organisms.