Attributions
Sources for the APTO knowledge base
APTO Study's study knowledge base is written in our own words and checked against the openly licensed sources below. We use them for facts only; no text is copied from them, and none of them endorses APTO Study. Your notes always come from your own slides first.
Biology 2e
- Author
- Mary Ann Clark, Matthew Douglas, Jung Choi
- Publisher
- OpenStax, Rice University
- Licence
- Creative Commons Attribution 4.0 International (CC BY 4.0)
- Source
- https://github.com/openstax/osbooks-biology-bundle/tree/d2779c2edfb435e75047325434fe2fe93d5aa120
- Version used
- d2779c2edfb435e75047325434fe2fe93d5aa120
- Used for
- ATP: adenosine triphosphate, the cell's energy currency · Acids, bases, pH and buffers in living things; solute concentration and molarity; ocean acidification · Active transport: pumps, membrane potential and cotransport · Atoms in biology: radioactive isotopes as tools, electron shells, valence and orbitals · Binary fission in prokaryotes and the evolution of mitosis · Bulk transport: exocytosis and endocytosis · Cancer: loss of cell cycle control · Carbohydrates: sugars, starch, glycogen, cellulose and chitin · Carbon and molecular diversity: organic chemistry, carbon skeletons, hydrocarbons and isomers · Cell cycle control: checkpoints, cyclins and Cdks · Cell division: genomes, chromosomes and sister chromatids · Cell signaling: local and long-distance signals, and receptors · Cell walls, the extracellular matrix and cell junctions · Cellular respiration overview: redox, NAD+ and the three stages · Chemical bonds in living things: covalent, ionic, hydrogen bonds and van der Waals interactions · Chemical reactions and chemical equilibrium in living things · Connecting respiration to other fuels: fats, proteins and biosynthesis · Enzymes: active sites, catalysis, inhibition and regulation · Eukaryotic cells: nucleus, ribosomes and organelles · Evolution, the core theme: unity and diversity, natural selection and the three domains · Fermentation and anaerobic respiration · Free energy: exergonic and endergonic reactions, coupling and activation energy · Glycolysis: splitting glucose into pyruvate · Lipids: fats, phospholipids and steroids · Macromolecules: polymers, monomers, dehydration and hydrolysis · Membrane structure: the fluid mosaic model · Metabolism: catabolic and anabolic pathways and forms of energy · Mitochondria, chloroplasts, peroxisomes and endosymbiosis · Nucleic acids: DNA, RNA and nucleotides · Oxidative phosphorylation: electron transport, chemiosmosis and ATP yield · Passive transport: diffusion, osmosis and tonicity · Photosynthesis overview: the equation, the leaf and the two stages · Prokaryotic cells and cell size (surface area to volume) · Proteins: amino acids, peptide bonds and the four levels of structure · Pyruvate oxidation and the citric acid cycle · Regulating cellular respiration: feedback at phosphofructokinase · Responses to signals: gene expression, amplification and apoptosis · Scientific inquiry: observation, hypotheses, experiments, theories and reasoning · Signal transduction: phosphorylation cascades and second messengers · Signaling in single-celled organisms: yeast mating and quorum sensing · Studying cells: microscopy and cell theory · The Calvin cycle and alternative carbon fixation (C3, C4, CAM) · The cell cycle: interphase, the phases of mitosis and cytokinesis · The cytoskeleton: microtubules, microfilaments, intermediate filaments · The elements of life: essential and trace elements, compounds and emergent properties · The endomembrane system: ER, Golgi, lysosomes and vacuoles · The laws of thermodynamics in living systems · The light reactions: pigments, photosystems and electron flow · The seven chemical groups most important to life, and their properties · Themes of biology: properties of life, levels of organisation, cells, DNA, energy and regulation · Water and life: polarity, hydrogen bonding, cohesion, temperature moderation, ice and the solvent of life
Biology 2e by Mary Ann Clark, Matthew Douglas and Jung Choi, OpenStax (Rice University), licensed under CC BY 4.0. Version used: the osbooks-biology-bundle repository at commit d2779c2, the last commit before the 2026-03-19 relicensing. Access the book free at openstax.org.
Facts and taxonomy (chapter/section structure, terminology) only, to check our items against. Every sentence in the Apex knowledge base is original writing; nothing is copied or adapted from the book's text. OpenStax and Rice University do not endorse Apex Study.
Microbiology
- Author
- Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister, Brian M. Forster
- Publisher
- OpenStax, Rice University
- Licence
- Creative Commons Attribution 4.0 International (CC BY 4.0)
- Source
- https://github.com/openstax/osbooks-microbiology/tree/ecf34dad129d686703780e87ab5aa2e59c577a6a
- Version used
- ecf34dad129d686703780e87ab5aa2e59c577a6a
- Used for
- Eukaryotic cells: nucleus, ribosomes and organelles · Prokaryotic cells and cell size (surface area to volume) · Studying cells: microscopy and cell theory · The cytoskeleton: microtubules, microfilaments, intermediate filaments · The elements of life: essential and trace elements, compounds and emergent properties · The endomembrane system: ER, Golgi, lysosomes and vacuoles · The seven chemical groups most important to life, and their properties
Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister and Brian M. Forster, OpenStax (Rice University), licensed under CC BY 4.0. Version used: the osbooks-microbiology repository at commit ecf34da, the last commit before the 2026-03-19 relicensing. Access the book free at openstax.org.
Facts only (microscopy, eukaryotic cell structures), to check our items against. Every sentence in the Apex knowledge base is original writing; nothing is copied or adapted from the book's text. OpenStax and Rice University do not endorse Apex Study.
Chemistry 2e
- Author
- Paul Flowers, Klaus Theopold, Richard Langley, William R. Robinson
- Publisher
- OpenStax, Rice University
- Licence
- Creative Commons Attribution 4.0 International (CC BY 4.0)
- Source
- https://github.com/openstax/osbooks-chemistry-bundle/tree/32c719622fbb7a0ca729cd645c1df4cf4e7d5b3a
- Version used
- 32c719622fbb7a0ca729cd645c1df4cf4e7d5b3a
- Used for
- Accuracy and precision · Acid–base (neutralization) reactions · Atomic number and mass number · Atoms and molecules · Average atomic mass · Bond energies, bond strength and lattice energy · Calorimetry: coffee-cup and bomb calorimeters · Chemical formulas · Chemical nomenclature · Chemical symbols · Classification of matter · Covalent bonds, electronegativity and bond polarity · Dalton's atomic theory · Density · Dilution of solutions · Dimensional analysis (factor-label method) · Discovery of the neutron (Chadwick) · Effusion and diffusion (Graham's law) · Electromagnetic radiation, photons and spectra · Electron configurations and orbital diagrams · Empirical and molecular formulas from composition data · Energy, heat and work · Enthalpy, the first law and thermochemical equations · Formal charges and resonance · Gas pressure and its units · Gas stoichiometry, gas density and partial pressures · Heat capacity and specific heat (q = mcΔT) · Hess's law and standard enthalpies of formation · Hybrid atomic orbitals (sp, sp², sp³, sp³d, sp³d²) · Intensive and extensive properties · Ionic and molecular compounds · Ionic bonding and the electron configurations of ions · Ions: cations, anions and ionic charge · Isotopes and nuclide symbols · Law of conservation of mass · Law of definite proportions · Law of multiple proportions · Lewis symbols, Lewis structures and the octet rule · Limiting reactant and excess reactant · Mass spectrometry and isotope abundance · Mass vs weight · Metric (SI) prefixes · Millikan's oil-drop experiment · Molarity (molar concentration) · Molecular orbital theory, bond order and magnetism · Molecular, complete ionic and net ionic equations · NFPA 704 hazard diamond · Other concentration units: percentages, ppm, ppb, mole fraction and molality · Oxidation–reduction reactions and oxidation numbers · Percent composition · Periodic trends: atomic radius, ionization energy and electron affinity · Phase changes · Physical and chemical changes · Physical and chemical properties · Precipitation reactions and solubility rules · Quantitative chemical analysis: titration, gravimetric and combustion analysis · Quantum theory: wave behaviour, orbitals and quantum numbers · Reaction stoichiometry: mole ratios and mass-to-mass calculations · Real gases and non-ideal behaviour · Rutherford's gold-foil experiment and the nuclear model · SI base units and derived units · Scientific (exponential) notation · Significant figures · States of matter · Subatomic particles: charge, mass and location · Temperature scales and conversions (K, °C, °F) · The Bohr model of the hydrogen atom · The gas laws and the ideal gas law · The kinetic-molecular theory · The mole, Avogadro's number and molar mass · The periodic table: groups, periods, metals and nonmetals · Theoretical yield, actual yield and percent yield · Thomson, cathode rays and the plum-pudding model · VSEPR theory, molecular shape and molecular polarity · Valence bond theory: orbital overlap, sigma and pi bonds · Volume units (cubic meter, liter, milliliter, cubic centimeter) · Water and life: polarity, hydrogen bonding, cohesion, temperature moderation, ice and the solvent of life · Writing and balancing chemical equations
Chemistry 2e by Paul Flowers, Klaus Theopold, Richard Langley and William R. Robinson, OpenStax (Rice University), licensed under CC BY 4.0. Version used: the osbooks-chemistry-bundle repository at commit 32c7196, the last commit before the 2026-03-19 relicensing. Access the book free at openstax.org.
Facts only, to check our items against. Every sentence in the Apex knowledge base is original writing; nothing is copied or adapted from the book's text. OpenStax and Rice University do not endorse Apex Study.
University Physics Volumes 1-3
- Author
- Samuel J. Ling, Jeff Sanny, William Moebs
- Publisher
- OpenStax, Rice University
- Licence
- Creative Commons Attribution 4.0 International (CC BY 4.0)
- Source
- https://github.com/openstax/osbooks-university-physics-bundle/tree/db44eb99e9aa1d918fd8cf182f82ccdece9c7b11
- Version used
- db44eb99e9aa1d918fd8cf182f82ccdece9c7b11
- Used for
- Acceleration and its sign · Archimedes' principle and buoyancy · Centripetal force: the net force of circular motion · Conduction, convection and radiation · Conservation of mechanical energy and energy bar charts · Conservation of momentum · Constant-acceleration kinematics: the kinematic equations · Damped and driven oscillations, resonance · Elastic and inelastic collisions · Energy in simple harmonic motion · Entropy and the second law · Flow rate, continuity and Bernoulli's equation · Fluids, density and pressure at depth · Forces, net force and free-body diagrams · Free fall: motion under gravity alone · Gauge pressure and Pascal's principle · Heat engines, refrigerators and the second law · Heat, specific heat and calorimetry · Hooke's law and restoring forces · Moment of inertia and Newton's second law for rotation · Momentum and impulse · Motion graphs: slopes, areas and calculus · Newton's first law and inertia · Newton's law of universal gravitation · Newton's second law, mass and weight · Newton's third law: action-reaction pairs · Normal force, tension and inclines · Orbits, weightlessness and Kepler's laws · Phase changes and latent heat · Position, displacement and distance traveled · Potential energy and conservative forces · Power · Projectile motion · Relative motion and adding velocities · Rotational kinematics: angular position, velocity and acceleration · Scalars, vectors and vector components · Simple harmonic motion: springs and pendulums · Solving Newton's-law problems: equilibrium and connected objects · Speed and velocity, average and instantaneous · Static and kinetic friction · Temperature, heat and thermal equilibrium · The first law of thermodynamics · The ideal gas law and kinetic theory · Thermal expansion · Thermodynamic processes and pV diagrams · Torque and static equilibrium · Uniform circular motion and centripetal acceleration · Viscosity, Poiseuille's equation and turbulence · Work, kinetic energy and the work-energy theorem
University Physics Volumes 1-3 by Samuel J. Ling, Jeff Sanny and William Moebs, OpenStax (Rice University), licensed under CC BY 4.0. Version used: the osbooks-university-physics-bundle repository at commit db44eb9, the last commit before the 2026-03-19 relicensing. Access the book free at openstax.org.
Facts and taxonomy (chapter/section structure, terminology) only, for the calculus-based mechanics/E&M cross-walk. Every sentence in the Apex knowledge base is original writing; nothing is copied or adapted from the book's text. OpenStax and Rice University do not endorse Apex Study.
Word lists for memory aids
Generated memory aids check acronyms against the 12dicts word lists (2of12 and 2of5core) compiled by Alan Beale and released by him to the public domain, with thanks. Source: wordlist.aspell.net/12dicts, version 6.0.2.
Fonts in exported PDFs
Chinese, Japanese and Korean text in PDFs is set in Noto Sans SC (Google Inc.), licensed under the SIL Open Font License 1.1 and packaged by Fontsource (fontsource.org/fonts/noto-sans-sc). Greek letters and maths symbols use Liberation Sans, also under the SIL Open Font License 1.1. Licence text: openfontlicense.org.