BIOL 141 Notes: The Science of Biology to The Chemical Building Blocks of Life (Ch. 1-3)

Vocabulary flashcards covering core terms from Chapters 1-3 (The Science of Biology, The Nature of Molecules, and The Chemical Building Blocks of Life).

Cellular organization

Living systems are organized into cells, with higher levels such as tissues, organs, and organ systems.

Ordered complexity

A high level of organization in living systems, with components arranged in a precise, functional order.

Sensitivity

Organisms respond to environmental stimuli.

Growth, development, and reproduction

Organisms increase in size, change over time, and reproduce to pass on traits.

Energy utilization

Living things capture, convert, and use energy to perform work.

Homeostasis

Maintenance of stable internal conditions despite external changes.

Evolutionary adaptation

Populations accumulate traits that improve survival and reproduction in their environment.

Emergent properties

New properties that arise at higher levels of organization that are absent in individual components.

Inductive reasoning

Reasoning from specific observations to general conclusions.

Deductive reasoning

Reasoning from general principles to specific predictions.

Hypothesis-driven science

Science guided by testable hypotheses and experiments.

Descriptive science

Science based on careful observation and description of phenomena.

Scientific theory

A well-supported, broadly applicable explanation of natural phenomena.

Natural selection

Differential survival and reproduction leading to trait frequencies changing over time.

Fossil record

Archive of ancient life showing historical evidence of evolution.

Homologous structures

Similar bone structures in different species indicating common ancestry.

Analogous structures

Structures with similar function but different origins; do not indicate common ancestry.

Molecular evidence

Genetic and molecular data supporting evolutionary relationships.

Atom

The basic unit of matter; composed of protons, neutrons, and electrons.

Proton

Positively charged subatomic particle in the nucleus; defines atomic number.

Neutron

Electrically neutral subatomic particle in the nucleus; contributes to mass.

Electron

Negatively charged subatomic particle orbiting the nucleus; involved in bonding.

Atomic number

Number of protons in the nucleus; identifies the element.

Atomic mass

Total mass of an atom (protons plus neutrons).

Ion

Atom or molecule with a net electric charge due to gain or loss of electrons.

Isotope

Atoms of the same element with different numbers of neutrons.

Half-life

Time required for half of a radioactive isotope to decay.

Orbital

Region around the nucleus where an electron is likely to be found.

Valence electrons

Electrons in the outermost shell involved in bonding.

Octet rule

Atoms tend to have eight electrons in their outer shell for stability.

Ionic bond

Bond formed by transfer of electrons, creating oppositely charged ions.

Covalent bond

Bond formed by sharing electrons between atoms.

Electronegativity

Attractive force of an atom for electrons in a bond; determines bond polarity.

Hydrogen bond

Weak attraction between a hydrogen atom in one molecule and an electronegative atom in another.

Capillary action

Movement of water in narrow spaces due to cohesion and adhesion.

pH scale

Scale measuring how acidic or basic a solution is.

Buffers

Substances that resist changes in pH by neutralizing added acids or bases.

Carbon

Element central to life; forms four covalent bonds and many diverse compounds.

Functional group

Specific group of atoms within a molecule that governs its chemical reactivity.

Isomer

Compound with the same formula as another but a different arrangement of atoms.

Monomer

Small, repeat unit that builds polymers.

Polymer

Large molecule built from many monomer units.

Carbohydrate

Biomolecule made of carbon, hydrogen, and oxygen; primary energy source and structural component.

Monosaccharide

Simple sugar; basic unit of carbohydrates.

Nucleic acid

Biomolecule that stores and transmits genetic information (DNA/RNA).

Nucleotide

Monomer of nucleic acids consisting of a sugar, phosphate, and a nitrogenous base.

Phosphodiester bond

Covalent bond linking nucleotides in nucleic acids.

Amino acid

Monomer of proteins; contains amino and carboxyl groups plus a side chain.

Peptide bond

Bond that links amino acids in a protein.

Protein

Macromolecule made of amino acids; performs diverse cellular functions.

Lipid

Hydrophobic biomolecule important for membranes and energy storage.

Phospholipid

Lipid with two fatty acid tails and a phosphate-containing head; major membrane component.

Phospholipid bilayer

Two-layer membrane structure with hydrophilic heads and hydrophobic tails.

Micelle

Spherical arrangement of amphipathic molecules in water with a hydrophobic core.