Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting,

TLS Online TPP Program

#Id: 8242

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 7224

#Unit 5. Developmental Biology

Two distinct selection processes are required

Positive selection, which selects for those thymocytes bearing receptors capable of binding self-MHC molecules, resulting in MHC restriction

Negative selection, which selects against thymocytes bearing high-affinity receptors for self-MHC/peptide complexes, resulting in self-tolerance.

TLS Online TPP Program

#Id: 6768

#Unit 3. Fundamental Processes

In nonsense mediated decay  in the addition of multiple lysines to the end of the protein (AAA is the codon for lysine) and stalling of the ribosome at the end of the mRNA. 

TLS Online TPP Program

#Id: 1025

#Unit 5. Developmental Biology

In mammals, Noggin (antagonist of BMP) is expressed in the notochord and neural folds.

TLS Online TPP Program

#Id: 7682

#Unit 1. Molecules and their Interaction Relevant to Biology

In fig, Phi is fixed at 0º. Clashes occur at ALL Psi angles. Phi = 0º is physically

impossible.