General Biology Study Guide: Key Concepts and Terms

Chapter 1: Modules 01.9, 01.11

Evolution and Natural Selection

Evolution is the process by which populations of organisms change over generations. Natural selection is a key mechanism of evolution, leading to adaptation and heritable variations within populations.

• Evolution: The change in the genetic composition of a population over time.

• Natural Selection: The process by which organisms better adapted to their environment tend to survive and produce more offspring.

• Adaptation: A trait that increases an organism's fitness in a particular environment.

• Heritable Variations: Genetic differences that can be passed from parents to offspring.

• Artificial Selection: The intentional breeding of organisms by humans for specific traits (e.g., dog breeds).

Cell Communication and Signaling

• Signaling Information: Cells communicate using chemical signals (e.g., control of blood sugar levels).

Chapter 34, 03.4, 03.5

Biomes and Climate

• Biomes: Large ecological areas on Earth's surface, with flora and fauna adapting to their environment (e.g., taiga, coral reefs).

• Temperature Zones: Regions of Earth with distinct climate patterns.

• Equinox vs. Solstice: Equinoxes are days when day and night are of equal length; solstices are the longest and shortest days of the year.

Chapter 2, 02.1-3, 02.5-9

Atoms and Molecules

• Atom: The smallest unit of matter, consisting of protons, neutrons, and electrons.

• Proton, Neutron, Electron: Subatomic particles; protons and neutrons are in the nucleus, electrons orbit the nucleus.

• Atomic Nucleus: The central part of an atom, containing protons and neutrons.

• Isotope: Atoms of the same element with different numbers of neutrons.

• Element: A substance that cannot be broken down into simpler substances by chemical means.

• Electron Shell: The region around the nucleus where electrons are likely to be found. Shaped like a sphere or dumbbell.

• Covalent Bond: A chemical bond formed by the sharing of electron pairs between atoms.

• Hydrogen Bond: A weak bond between two molecules resulting from an electrostatic attraction.

• Single vs. Double Bond: Single bonds share one pair of electrons; double bonds share two pairs.

• Polar vs. Non-Polar Bond: Polar bonds have unequal sharing of electrons; non-polar bonds have equal sharing.

Chapter 3, 03.1-5, 13.7, 08.3, 10.15

Organic and Inorganic Compounds

• Organic Compound: Contains carbon and is found in living things.

• Hydrophilic vs. Hydrophobic: Hydrophilic substances interact with water; hydrophobic substances do not.

• Functional Groups: Specific groups of atoms within molecules that have characteristic properties (e.g., hydroxyl, carboxyl, amino, phosphate).

• Monomer vs. Polymer: Monomers are small molecules that can join to form polymers.

• Carbohydrates, Lipids, Proteins, Nucleic Acids: The four major classes of biological macromolecules.

• Carbohydrate Monomer: Monosaccharide (simple sugar).

• Lipid: Includes fats, phospholipids, waxes, and steroids.

• Triglyceride: Composed of glycerol and three fatty acids.

• Protein: Made of amino acids linked by peptide bonds.

• Peptide Bond: The bond between two amino acids.

• Polypeptide vs. Protein: A polypeptide is a chain of amino acids; a protein is one or more polypeptides folded into a functional shape.

• Nucleotide: The monomer of nucleic acids (DNA and RNA).

Chapter 4, 04.1-5, 04.7-8

Cell Structure and Function

• Cell: The basic unit of life.

• Organelle: Specialized structure within a cell (e.g., nucleus, mitochondria).

• Prokaryote vs. Eukaryote: Prokaryotes lack a nucleus; eukaryotes have a nucleus.

• Cell Wall: Rigid outer layer found in plants, fungi, and some bacteria.

• Plasma Membrane: The cell's outer boundary, controlling movement of substances in and out.

• Cytoskeleton: Network of protein filaments that provide structure and shape.

• Endomembrane System: Includes the endoplasmic reticulum (smooth and rough), Golgi complex, lysosomes, and vesicles.

• Mitochondrion: Organelle responsible for energy production (ATP).

• Chloroplast: Organelle in plants where photosynthesis occurs.

• Microtubules, Microfilaments, Intermediate Filaments: Components of the cytoskeleton.

• Actin vs. Tubulin vs. Keratin: Types of proteins forming cytoskeletal elements.

Chapter 5, 05.10-15

Energy and Enzymes

• Potential vs. Kinetic Energy: Potential energy is stored energy; kinetic energy is energy of motion.

• Endergonic vs. Exergonic Reactions: Endergonic reactions absorb energy; exergonic reactions release energy.

• Activation Energy: The minimum energy required to start a chemical reaction.

• Transition State: The state during a reaction when bonds in the reactants are stretched and ready to break/form.

• ATP: Adenosine triphosphate, the main energy currency of the cell.

• Enzyme vs. Cofactor (Coenzyme) vs. Catalyst: Enzymes are biological catalysts; cofactors/coenzymes assist enzyme function; catalysts speed up reactions without being consumed.

Chapter 6, 06.2-3, 06.5-11, 06.13-17

Metabolic Pathways and Cellular Respiration

• Metabolic Pathway: A chain of enzyme-catalyzed reactions (can be biosynthetic or catabolic).

• Catabolic Pathway: Metabolic pathway that breaks down food to obtain energy.

• Substrate: The reactant on which an enzyme acts.

• Product: The substance formed as a result of a chemical reaction.

• Fermentation vs. Aerobic Respiration: Fermentation occurs without oxygen; aerobic respiration requires oxygen.

• Glycolysis: The breakdown of glucose to pyruvate, producing ATP and NADH.

• Pyruvate, Lactic Acid, Ethanol: Products of glycolysis and fermentation.

• Electron Transport Chain: Series of proteins that transfer electrons to generate ATP.

• Chemiosmosis: The movement of ions across a membrane to produce ATP.

• Feedback Inhibition: A method of metabolic control where the end product inhibits an earlier step.

• Allosteric Enzyme: An enzyme whose activity is regulated by the binding of a molecule at a site other than the active site.

• Competitive vs. Non-Competitive Inhibitor: Competitive inhibitors bind to the active site; non-competitive inhibitors bind elsewhere.

Chapter 8, 08.15-18, 11.2, 13.14, 08.16

Cell Division: Mitosis and Meiosis

• Chromosome vs. Chromatid vs. Centromere: Chromosomes are DNA molecules; chromatids are duplicated chromosomes; centromere is the region where chromatids are joined.

• Cell Cycle Phases: Interphase (cell growth), S phase (DNA synthesis), M phase (mitosis), Telophase (end of mitosis).

• Mitotic Spindle vs. Centrosome vs. Kinetochore: Structures involved in chromosome movement during cell division.

• Haploid vs. Diploid: Haploid cells have one set of chromosomes; diploid cells have two sets.

• Mitosis vs. Meiosis vs. Cytokinesis: Mitosis produces identical cells; meiosis produces gametes with half the chromosome number; cytokinesis is the division of the cytoplasm.

add isomer, ion and inert element