Biochemistry · Undergraduate
Lehninger Principles of Biochemistry
David L. Nelson, Michael M. Cox · 2017
Standard biochemistry text used in medical and life-science programs around the world.
Inside the book
Nelson and Cox's Lehninger Principles of Biochemistry is the definitive textbook of the chemistry of life, now in its 7th edition.
Key ideas covered:
• The molecular logic of living organisms: proteins, enzymes, carbohydrates, lipids and nucleic acids.
• Enzyme kinetics and mechanism — how catalysts make life's chemistry fast and specific.
• Metabolism: glycolysis, the citric acid cycle, oxidative phosphorylation, photosynthesis.
• Bioenergetics — how ATP captures and spends the energy of food and sunlight.
• Genes, chromosomes, and the biochemistry of DNA replication, transcription and protein synthesis.
• Signal transduction and the molecular basis of regulation and disease.
Why it matters: It connects chemistry directly to medicine and biology, and is the standard text for medical and life-science students worldwide.
Read the book — chapter by chapter
Chapter 1 — The Molecular Logic of Life
Living things are built from a small set of molecules: amino acids, sugars, fatty acids and nucleotides, joined into proteins, polysaccharides, lipids and nucleic acids. Cells are open systems that take in energy and use it to keep order, obeying the same laws of thermodynamics as any chemical system.
Water shapes everything: hydrogen bonding, the hydrophobic effect and pH control how biomolecules fold and interact. Buffers keep blood near pH 7.4.
Chapter 2 — Proteins and Enzymes
Proteins are chains of twenty amino acids linked by peptide bonds. Their sequence (primary structure) folds into alpha-helices and beta-sheets (secondary), a 3-D shape (tertiary), and sometimes multi-chain assemblies (quaternary). Haemoglobin shows how shape changes allow cooperative oxygen binding.
Enzymes are protein catalysts that lower activation energy. Michaelis–Menten kinetics, v = Vmax[S]/(Km + [S]), describes how rate depends on substrate concentration; inhibitors can be competitive or non-competitive, the basis of many drugs.
Chapter 3 — Metabolism and Energy
ATP is the energy currency of the cell. Glycolysis splits glucose into two pyruvate, making a little ATP and NADH. The citric acid cycle oxidises acetyl-CoA to CO₂, loading more NADH and FADH₂. In oxidative phosphorylation these carriers pass electrons along a chain in the mitochondrial membrane, pumping protons; ATP synthase uses the proton flow to make about 30 ATP per glucose.
Photosynthesis runs a similar system in reverse, using light to split water and fix CO₂ into sugar.
Chapter 4 — Information: DNA, RNA and Proteins
DNA is a double helix of two strands paired A–T and G–C. It is copied semi-conservatively by DNA polymerase. Genes are transcribed into messenger RNA, which ribosomes translate into proteins using the genetic code, three bases per amino acid.
The book closes with how gene expression is regulated and how techniques such as PCR, sequencing and CRISPR let chemists read and edit this information.