Selenocysteine, sometimes called the “twenty-first amino acid,”

is incorporated into proteins with the aid of a tRNA that interprets the UGA Stop codon as a Sec codon. tRNASec is initially charged with serine in a reaction catalyzed by the same SerRS that charges tRNASer.

TLS Online TPP Program

#Id: 1592

#Unit 5. Developmental Biology

A regional thickening of cells at the anterior end of the primitive streak

TLS Online TPP Program

#Id: 7228

#Unit 5. Developmental Biology

Superantigens

Viral or bacterial proteins that bind simultaneously to the Vβ domain of a T-cell receptor and to the α chain of a Class II MHC molecule

TLS Online TPP Program

#Id: 9002

#Unit 6. System Physiology – Plant

Prior to CO2 fixation, Activation of RUBISCO/Carbamylation of RUBISCO takes place

1. Two protons are released. 

2. Binding of CO2 molecule on NH2 group

3. Binding of Mg2+ concentration upon illumination

TLS Online TPP Program

#Id: 10192

#Unit 6. System Physiology – Plant

cZ is thought to be less active and relatively more stable than tZ and iP because of its low affinity for CKX. cZ and its conjugates are more abundant than tZ‐ and iP‐type CKs in Z. mays, O. sativa, chickpea (Cicer arietinum) and a moss (Physcomitrella patens)

TLS Online TPP Program

#Id: 9072

#Unit 4. Cell Communication and Cell Signaling

In resting state 

basal level of PDE activity keeps cAMP levels below those necessary for PKA activation.