Amino Acid Biosynthesis and Nitrogen Cycle

These flashcards cover key vocabulary and concepts related to amino acid biosynthesis and the nitrogen cycle in biochemistry.

Essential Amino Acids

Amino acids that cannot be synthesized by mammals and must be obtained through diet.

Non-Essential Amino Acids

Amino acids that can be synthesized by mammals and are not required in the diet.

Diazotrophs

Microorganisms that can convert nitrogen gas (N₂) into ammonia (NH3).

Nitrogen Fixation

The process of converting nitrogen gas into ammonia, catalyzed by the nitrogenase complex.

Glutamate Dehydrogenase (GDH)

An enzyme that catalyzes the conversion of α-ketoglutarate into glutamate.

GS-GOGAT Pathway

Pathway for the conversion of glutamate to glutamine and back, involving glutamine synthetase and glutamate synthase.

Transamination Reactions

Reactions that transfer amino groups to keto acids, forming new amino acids.

Phenylalanine Hydroxylase

An enzyme that converts phenylalanine into tyrosine.

Essential Amino Acid Mnemonic

PVT TIM HALL helps remember essential amino acids: Phenylalanine, Valine, Threonine, Tryptophan, Isoleucine, Methionine, Histidine, Arginine, Leucine, Lysine.

Nitrate Assimilation

The process by which plants and bacteria convert nitrate into organic nitrogen compounds like amino acids.

Glutamine Synthetase

An enzyme that catalyzes the reaction that forms glutamine from glutamate and ammonia.

Nitrogen Cycle

The cycle through which nitrogen is converted between its various chemical forms in the environment.

Nitrate Conversion

The process by which nitrate ions (NO3-) are reduced to ammonia (NH3) for plant use.

Alanine Transaminase (ALT)

An enzyme that catalyzes the transamination of pyruvate to alanine.

Aspartate Transaminase (AST)

An enzyme that catalyzes the transamination of oxaloacetate to aspartate.

Arginine Biosynthesis

The synthesis of arginine from glutamate via the urea cycle.

Cysteine Synthesis

Synthesis from homocysteine and serine through cystathionine intermediary.

Homocysteine

A sulfur-containing amino acid involved in the synthesis of cysteine.

Transaminase

Enzyme that catalyzes the transfer of amino groups between amino acids and keto acids.

3-Phosphoglycerate

An intermediate in glycolysis that can be converted into serine, glycine, and cysteine.

Oxaloacetate

A four-carbon dicarboxylic acid that participates in several metabolic pathways.

Pyruvate

A key intermediate in glucose metabolism and a precursor for alanine synthesis.

α-Ketoglutarate

A five-carbon molecule that plays a key role in the TCA cycle and amino acid synthesis.

Amino Sugar

A sugar that contains an amino group replacing a hydroxyl group.

Coenzymes

Organic molecules that assist enzymes in catalyzing reactions.

Porphyrins

Cyclic compounds that are essential for the synthesis of heme and chlorophyll.

Energy Metabolism

The biochemical processes that create energy from nutrients.

Complex Polysaccharides

Large molecules made of long chains of monosaccharides that serve as energy storage.

Methyl Cycle

A biological cycle that involves the transfer of methyl groups and is critical for DNA synthesis.

Intermediate in Biosynthesis

Substances formed during the multi-step chemical reactions necessary for biosynthesis.

Metabolic Pathways

Series of chemical reactions within a cell that lead to the biosynthesis of molecules.

Essential vs Non-Essential Nutritional Requirements

Differences in dietary needs for amino acids that are essential versus those that can be synthesized by the body.