Quick Pep

I Brand Name(s) Caffedrine, Dexitac Stay Alert Stimulant, Enerjets, Keep Alert, NoDoz, Pep Back, Ultra Pep-Back, Quick Pep, Vivarin Cfiemical Class Xanthine derivative... 

Note that the single-letter abbreviations permit a fast comparison of the sequences so that their differences and similarities can quickly be discerned. The sequences for C-pep-tides from humans and from rats are compared below (differences are highlighted) ... 

Sometimes doctors prescribe methylphenidate (Ritalin) or dextroamphetamine (Dexedrine) to treat a mood disorder called dysthymia that is less severe, but more chronic, than major depression. They work more quickly than antidepressants to pep you up, increasing energy and facilitating attention and concentration. Common side effects include nervousness, insomnia, constipation, headache, and changes in heart rate. 

Tryptophan synthase catalyzes the last two steps of the biosynthesis of tryptophan. It is typically found as a tetramer. The a subunits catalyze the reversible formation of indole and G3P from InGP. The p subunits catalyze the irreversible condensation of indole and serine to form tryptophan in a PLP-dependent reaction. Each a active site is connected to a p active site in a process known as substrate channeling [18]. Eigure 14.7 represents the stereo view of one ap heterodimer of tryptophan [19]. The a subunit contains bound indole-3-propanol phosphate and p subunit contains L-serine, which forms aldimine with the coenzyme PEP The orange sphere represents the course of tunnel running from the a to the p subunits. This tunnel is a 25 A long hydrophobic channel contained within the enzyme allowing for the diffusion of indole. If the channel did not exist, the indole formed at a active site would quickly diffuse always and be lost to the cell as it is hydrophobic and can easily cross membranes. 

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