Level of life
Protein
A chain of amino acids folded into a working shape. Proteins act as enzymes, structures, signals and transporters.
Enzyme
A biological catalyst that speeds up a reaction without being used up. Most are proteins, but some RNAs are catalysts too, including the core of the ribosome.Source: OpenStax, 2018Source: Nissen et al., 2000
Also called catalyst.
Molecule
How Enzyme connects
Enzyme is an example of
Enzyme is described by
Idea or model
Enzyme kinetics
How reaction speed depends on substrate concentration: it rises and then levels off, as the Michaelis-Menten equation describes.
Enzyme includes the example
Molecule
Rubisco
The enzyme that captures carbon dioxide in photosynthesis, often called the most abundant protein on Earth.
Enzyme is used by
Technology or method
Metabolic engineering
Rewiring a microbe's chemistry to make useful molecules, such as a precursor of the antimalarial drug artemisinin in yeast.
Enzyme is related to
Structure
Ribosomes
Build proteins by reading messenger RNA.
Studied in
Your progress
Sources & further reading
The explanations on this page are our own summaries of these sources. Follow a link to read the original; if anything here disagrees with it, the original wins. How we choose and check sources.
Biology 2e (opens the original in a new tab)
OpenStax (2018). OpenStax, Rice University.
Free introductory college textbook.
TextbookEducationalLicence: CC BY-NC-SA 4.0 (linked, not reused)
The structural basis of ribosome activity in peptide bond synthesis (opens the original in a new tab)
Nissen P, Hansen J, Ban N, et al. (2000). Science 289:920-930.
Structural evidence that ribosomal RNA, not protein, catalyzes peptide bond formation.
Peer-reviewedPrimary research