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Incoming links: Phosphate
Substrate-level phosphorylation Created 2026-10-14 Updated 2026-10-18
Substrate-level phosphorylation forms ATP by enzyme-catalyzed transfer of a phosphate group from a phosphorylated substrate to ADP. In canonical glycolysis, two such transfers occur for each three-carbon route, giving four gross ATP per glucose. Unlike oxidative phosphorylation, these transfers do not require an electron transport chain.[ref]
Biology 2e by Mary Ann Clark and others. §7.2, steps 7 and 10: phosphate transfer to ADP; §7.5, opening comparison of fermentation with respiration
The pyruvate kinase example under Coupled-enzyme readout of glycolytic ATP formation separates the material transfer from its detection. A favourable coupled chemical reaction supplies the driving change in Gibbs free energy; the enzyme supplies a catalytic route. Counting ATP-forming transfers gives a gross yield, while subtracting upstream ATP use gives the net yield.
Triglyceride Created 2026-10-13 Updated 2026-10-14
A triglyceride contains glycerol joined to three fatty acid-derived acyl groups through ester linkages. Compare the three chains with the two-chain, phosphate-headed glycerophospholipid illustrated below. See Biology 2e: fats and oils.
Triose phosphate 2026-10-13
A triose phosphate is a three-carbon sugar carrying a phosphate group. Glyceraldehyde 3-phosphate is one example. The Calvin cycle supplies a net triose phosphate for further carbohydrate synthesis. [ref]
https://openstax.org/books/biology-2e/pages/8-3-using-light-energy-to-make-organic-molecules. OpenStax Biology 2e, 8.3: the Calvin cycle's carbohydrate product
. Tyrosine residue Created 2026-10-13 Updated 2026-10-14
A tyrosine residue is an amino acid residue whose amino acid side chain can accept a phosphate group during receptor tyrosine kinase signaling. The conventional one-letter sequence symbol is .
Wee1 Created 2026-10-14 Updated 2026-10-14
Wee1 is a protein kinase that inhibits CDK1 by adding a phosphate group at an inhibitory site. Purified human Wee1 phosphorylated Cdc2 at Tyr15 in the reported in vitro assay, with no Thr14 modification detected. A catalytic-site mutation abolished both the measured protein kinase activity and the ability to inhibit division. This identifies a catalytic brake rather than merely a correlated protein amount.[ref]
Human Wee1 kinase inhibits cell division by phosphorylating p34cdc2 exclusively on Tyr15 by Clare McGowan and others. McGowan and Russell (1993), abstract: purified human Wee1, Tyr15 specificity, no detectable Thr14 phosphorylation, and Lys114 mutant control
Do not attribute all inhibitory CDK1 phosphorylation to Wee1: the Xenopus laevis Myt1 experiment separately identified activity toward both Thr14 and Tyr15. Nor does every phosphorylation inhibit its target: activating Thr161 modification in the studied Xenopus laevis Cdc2 has the opposite role. In cell-cycle activation feedback, suppression of Wee1 removes a brake on CDK1, reinforcing the transition without implying that the total amount of either protein instantly disappears.