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

TLS Online TPP Program

#Id: 8907

#Unit 2. Cellular Organization

Centromere associated cohesins are specifically protected from phosphorylation dependent removal by protein phosphatase 2A

TLS Online TPP Program

#Id: 466

#Unit 2. Cellular Organization

Overlapping gene are the same sequence of DNA encodes two nonhomologous proteins because it uses more than one reading frame.

TLS Online TPP Program

#Id: 1211

#Unit 7. System Physiology – Animal

The last 14 days of the menstrual cycle are dominated by the corpus luteum (luteal phase).

TLS Online TPP Program

#Id: 8701

#Unit 1. Molecules and their Interaction Relevant to Biology

TLS Online TPP Program

#Id: 8459

#Unit 1. Molecules and their Interaction Relevant to Biology

Five types of constraints affect the stability of an  helix: 

(1) the intrinsic propensity of an amino acid residue to form an  helix; 

(2) the interactions between R groups, particularly those spaced three (or four) residues apart; 

(3) the bulkiness of adjacent R groups; 

(4) the occurrence of Pro and Gly residues; and 

(5) interactions between amino acid residues at the ends of the helical segment and the electric dipole inherent to the  helix.