Experimental studies on the quality of food proteins.

1. This paper reviews chemical and biological assays for measuring the quality of food proteins. 2. The availability of amino acids in a protein is determined by digestability and the capacity of the recipient animal to absorb the amino acids. 3. Intracellularly amino acid concentration influences enzyme activities associated with amino acid and nitrogen metabolism. 4. Amino acids utilized for metabolism affect the cells at the gene level: transcription of DNA to RNA and translation of RNA to protein. 5. More accurate measurements of amino acid utilization for metabolism will follow from further understanding of basic cellular metabolic events.