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AP Biology glossary of key terms with definitions, must-know facts, and related terms you need to know for your exam.
The information presented and examples highlighted in this section support concepts and Learning Objectives outlined in Big Idea 2 of the AP ® Biology Curriculum Framework.
1.1 The Science of Biology; 1.2 Themes and Concepts of Biology; Key Terms; Chapter Summary; Review Questions; Critical Thinking Questions; Test Prep for AP® Courses
1.1 The Science of Biology; 1.2 Themes and Concepts of Biology; Key Terms; Chapter Summary; Review Questions; Critical Thinking Questions; Test Prep for AP® Courses
- Key Concepts and Definitions
- Atomic Structure and Chemical Bonds
- Water and Its Properties
- Carbon and Organic Molecules
- Macromolecules: Structure and Function
- Enzymes and Biochemical Reactions
- Energy in Living Systems
- Practical Applications and Lab Techniques
- Common Misconceptions and FAQs
Matter consists of atoms, the fundamental building blocks of all substancesElements are pure substances that cannot be broken down into simpler substances by chemical means and are composed of only one type of atomCompounds are substances made up of two or more elements that are chemically combined in a specific ratioMolecules are groups of atoms held together by chemical bonds and can be composed of the same or different elementsAtoms consist of protons, neutrons, and electronsThe atomic number of an element is equal to the number of protons in its nucleus, which determines its identityIsotopes are atoms of the same element that have different numbers of neutrons, resulting in different atomic massesChemical bonds form when atoms share or transfer electrons to achieve a more stable electronic configurationWater is a polar molecule due to the uneven distribution of electrons between the oxygen and hydrogen atoms, resulting in a slightly positive charge on the hydrogen atoms and a slightly negative ch...Hydrogen bonding between water molecules gives rise to many of water's unique properties, such as high surface tension, cohesion, and adhesionWater has a high specific heat capacity, meaning it can absorb or release a large amount of heat energy without significantly changing its temperature, which helps regulate the temperature of livin...Water's high heat of vaporization allows it to absorb a large amount of heat energy during evaporation, which helps cool surfaces and regulate body temperature through sweatingCarbon is the basis for all organic molecules due to its ability to form four stable covalent bonds and create a wide variety of complex structuresHydrocarbons are organic molecules composed entirely of carbon and hydrogen atoms, such as methane (CH4) and benzene (C6H6)Functional groups are specific arrangements of atoms within organic molecules that give them distinct chemical propertiesIsomers are compounds that have the same molecular formula but different structural arrangements, resulting in different propertiesCarbohydrates are organic molecules composed of carbon, hydrogen, and oxygen atoms, typically in a 1:2:1 ratioLipids are a diverse group of hydrophobic organic molecules that include fats, oils, waxes, and steroidsProteins are large, complex molecules composed of amino acids linked together by peptide bondsNucleic acids are organic molecules that store and transmit genetic information in living organismsEnzymes are biological catalysts that speed up chemical reactions in living organisms without being consumed in the processThe active site of an enzyme is a specific region where the substrate binds and the reaction takes placeEnzymes lower the activation energy of a reaction by stabilizing the transition state, allowing the reaction to proceed more quicklyFactors that affect enzyme activity include temperature, pH, substrate concentration, and the presence of inhibitors or activatorsEnergy is the capacity to do work or cause change and is required for all life processesThe first law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to anotherThe second law of thermodynamics states that every energy transfer or transformation increases the entropy (disorder) of the universeAdenosine triphosphate (ATP) is the primary energy currency in living organisms, used to power cellular processes such as metabolism, transport, and movementSpectrophotometry is a technique used to measure the absorption of light by a sample at different wavelengths, which can be used to determine the concentration of a substance or monitor the progres...Chromatography is a method used to separate mixtures of compounds based on their differential affinities for a stationary phase and a mobile phaseElectrophoresis is a technique used to separate charged molecules (such as proteins or nucleic acids) based on their size and charge when subjected to an electric fieldEnzyme assays are used to measure the activity of an enzyme by monitoring the rate at which it catalyzes a specific reactionMisconception: Atoms are the smallest particles of matter.Misconception: All bonds involve the sharing of electrons.Misconception: Water is a universal solvent because it can dissolve anything.Misconception: All organic molecules contain carbon and hydrogen.The anterior-posterior polarity of the embryo, larva, and adult has its origin in the anterior-posterior polarity of the egg (Figure 9.8). The maternal effect genes expressed in the mother's ovaries produce messenger RNAs that are placed in different regions of the egg.
What is an Atomic Orbital? Orbitals and Orbits. When the a planet moves around the sun, you can plot a definite path for it which is called an orbit. A simple view of the atom looks similar and you may have pictured the electrons as orbiting around the nucleus.
