Cells of the pancreas will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized prot
eins enables a researcher to track the location of these proteins in a cell. In this case, we are tracking an enzyme that is eventually secreted by pancreatic cells. Which of the following is the most likely pathway for movement of this protein in the cell?
laboratories came to adopt the technique for protein synthesis for the purposes of answering the age-old question: exactly what role do amino acids play in proteins? Scientists Marshall Nirenberg and Heinrich Matthaei made a huge breakthrough in the answer to this fundamental question in 1961, successfully applying cell-free protein expression to make the connection between nucleotide triplets and the amino acids they encode.
Using an in vitro translation system based on E. coli, they were able to synthesize the polypeptide polyphenylalanine. From there, they were able to determine the connection between the amino acid phenylalanine and its corresponding codon UUU, essentially discovering the key to cracking the genetic code. This groundbreaking experiment would eventually lead to the deciphering of all the remaining amino acid codons and laid the foundation for the wide variety of translation biology systems that are available today
Cell-free expression begins with crude extracts generated from cultured cells that are typically engaged in a high rate of protein synthesis, such as immature red blood cells (reticulocytes). These crude extracts are depleted of their endogenous DNA and mRNA, and the cell lysate is subsequently supplemented with macromolecular components required to perform translation, including ribosomes, tRNAs, aminoacyl-tRNA synthetases and initiation, elongation and termination factors.
Aldosterone hormone would be released in high quantities
when the electrolyte balance in the body is low. This would enable the sodium
ions to be reabsorbed from the glomerular filtrate by the nephrons’ tubules.
ADH (Anti-duretic hormone), on the other hand, would be released in high amounts
if the electrolyte concentration in the body is high. This would enable the
high re-absorption of water from the glomerular filtrate.
The process that is not essential to the survival of an individual animal is reproduction process. Reproduction is not necessary for the survival of an individual organism, however it is very important to reproduce for the survival of the species.