Biology
Metabolism
Photosynthesis, respiration, ATP, enzymes.
Basics
ATP
The cell’s short-term energy currency. Hydrolysis (ATP → ADP + Pᵢ) is coupled to endergonic work. Most ATP comes from oxidative phosphorylation.
Cellular respiration
Glycolysis (cytosol) → pyruvate oxidation and the TCA cycle (mitochondria) → electron transport and chemiosmosis. O₂ is the terminal acceptor. Without oxygen, fermentation regenerates NAD⁺.
Photosynthesis
Light reactions split H₂O, releasing O₂ and making ATP and NADPH. The Calvin cycle fixes CO₂ into sugar. Chlorophyll absorbs mainly blue and red.
Enzymes
Catalysts that lower activation energy. Substrate-specific, with an optimum pH and temperature. Competitive inhibition: same V_max, higher K_m.
Formulas
Respiration (overall)
Oxidation of glucose. Net ATP is often around 30, depending on shuttle and conditions.
Photosynthesis (overall)
Looks like the reverse of respiration; the pathway is not the reverse.
Michaelis–Menten
If [S]≪K_m, rate is linear in substrate. If [S]≫K_m, rate approaches V_max.
Symbols
-
vinitial rate -
K_mMichaelis constant -
[S]substrate concentration
In this field
The cell
Prokaryotes vs eukaryotes, organelles, membranes.
Genetics and molecular biology
DNA, transcription/translation, Mendel, meiosis.
Evolution and ecology
Natural selection, phylogeny, trophic levels, cycles.
Human physiology basics
Homeostasis, circulation, nerves, immunity.
Plants and development
Plant tissues, hormones, developmental stages.
Immunity and microbes
Pathogens, innate and adaptive immunity, antibiotics and vaccines.
Nervous and endocrine systems
Neurons, synapses, hormones, and homeostasis — fast electrical and slower chemical signals.
Molecular lab sketch
Restriction enzymes, electrophoresis, PCR, and sequencing — a short principle sketch.
Population ecology
Exponential and logistic growth, carrying capacity, life history, predator–prey sketch.
Life’s diversity
Domains, a phylogeny sketch, homology versus analogy, and binomial names.
Biological macromolecules
Carbohydrates, lipids, proteins, and nucleic acids — structure and role sketches.