The synthetic pathways for the essential amino acids are:

You have previously studied the oxidative deamination of glutamate byglutamate dehydrogenase, in which NH3 and ketoglutarateare produced. The -ketoglutarate produced is thenavailable for accepting amino groups in other transamination reactions, but theaccumulation of ammonia as the other product of this reaction is a problembecause, in high concentrations, it is toxic. To keep the level of NH3in a controlled range, a rising level of -ketoglutarateactivates glutamine synthetase, increasing the production of glutamine, whichdonates its amino group in various other reactions.

Control of isoleucine, valine, and leucine biosynthesis.

 [EC 4.2.1.9] catalyzes the penultimate step in the synthesis of valine and isoleucine.

Product activation of yeast threonine dehydratase by ammonia.

A form of this enzyme present predominantly in younger leaves is considered to be the "biosynthetic" form of the enzyme because it is feedback inhibited by isoleucine.

Saccharomyces cerevisiae valine biosynthesis

Biofilm: complex aggregation of microorganisms marked by the excretion of a protective and adhesive matrix. Cropping: refers to the removal of the yeast which has settled to the bottom of the fermenter at the end of the fermentation. Cropped yeast can either be discarded, stored or re-used straight away.

Singh BK, Shaner DL 1995 Biosynthesis of branched chain amino acids: From test tube to field.

Amino Acid Synthesis - Rensselaer Polytechnic Institute

We will consider one important step in the synthesis of this group of 3 aminoacids, namely the step in which homocysteine is converted to methionine,catalyzed by the enzyme :

Synthesis of Nonessential Amino Acids

Metabolism1.0 Global and overview maps1.1 Carbohydrate metabolism1.2 Energy metabolism1.3 Lipid metabolism1.4 Nucleotide metabolism1.5 Amino acid metabolism1.6 Metabolism of other amino acids1.7 Glycan biosynthesis and metabolism1.8 Metabolism of cofactors and vitamins1.9 Metabolism of terpenoids and polyketides1.10 Biosynthesis of other secondary metabolites1.11 Xenobiotics biodegradation and metabolism1.12 Chemical structure transformation maps

Use of the valine biosynthetic pathway to convert glucose into ..

has 3 isozymes of aspartokinase that respond differently toeach of the 3 amino acids, with regard to enzyme inhibition and feedbackinhibition. The biosynthesis of lysine, methionine and threonine are not, then,controlled as a group.

Cysteine is synthesized from serine and homocysteine (methionine breakdownproduct):

Synthesis of L-alanine and L-valine by enzyme systems …

However, “now there’s been a push to try to make it for fuel and other chemical purposes,” says Avalos, the paper’s lead author.

Yeast typically produce isobutanol in a series of reactions that take place in two different cell locations.

Singh BK, Shaner DL 1995 Biosynthesis of branched chain amino acids: From test tube to field.

a side product of valine synthesis, ..

Skimming: refers to the removal of excess top-fermenting yeast which rises to the top of open-air fermenters during the fermentation process.

The regulation of synthesis of leucine biosynthetic enzymes in Neurospora.

α-Isopropylmalate, a Leucine Biosynthesis Intermediate …

We will see THF again when we study the synthesis of thymidylate from dUMP,catalyzed by the enzyme inwhich N5,N10-methylene-THF is the methyl donor.