The Xist transcript is regulated in a negative manner by Tsix, its antisense partner.

TLS Online TPP Program

#Id: 8040

#Unit 1. Molecules and their Interaction Relevant to Biology

TLS Online TPP Program

#Id: 8041

#Unit 1. Molecules and their Interaction Relevant to Biology

There are two type representation of amino acid structure

1. By Fischer’s convention L and D

2. By absolute configuration RS System

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#Id: 8042

#Unit 1. Molecules and their Interaction Relevant to Biology

A system to unambiguously describe the configurations of molecules with more than one asymmetric center was devised in 1956 by Robert Cahn, Christopher Ingold, and Vladimir Prelog. In the Cahn–Ingold– Prelog or RS system

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#Id: 8043

#Unit 1. Molecules and their Interaction Relevant to Biology

RS Configuration 

Atoms of higher atomic number rank above those of lower atomic number (e.g., —OH ranks above —CH3). If the first substituent atoms are identical, the priority is established by the next atom outward from the chiral center (e.g., —CH2OH takes precedence over —CH3).

TLS Online TPP Program

#Id: 8044

#Unit 1. Molecules and their Interaction Relevant to Biology

The order of priority of some common functional groups in amino acids is

TLS Online TPP Program

#Id: 8045

#Unit 1. Molecules and their Interaction Relevant to Biology