The SA node exhibits automaticity; it can spontaneously generate action potentials without neural input.

TLS Online TPP Program

#Id: 1541

#Unit 2. Cellular Organization

Kinesin-13 (End-Binding Proteins)

• Bind and curve the end of the tubulin protofilaments into the GDP-β-tubulin conformation

• Facilitate the removal of terminal tubulin dimers 

• Greatly enhancing the frequency of catastrophes

TLS Online TPP Program

#Id: 750

#Unit 3. Fundamental Processes

rNTPs are present at approximately 10-fold higher concentration in the cell, they are incorporated at a rate that is more than 1000-fold lower than dNTPs.

TLS Online TPP Program

#Id: 5097

#Unit 6. System Physiology – Plant

Plant phytochrome is an autophosphorylating serine/threonine kinase that may phosphorylate other proteins (X).

TLS Online TPP Program

#Id: 1570

#Unit 4. Cell Communication and Cell Signaling

Homologs

LRP in vertebrates = Arrow in Drosophila.

TLS Online TPP Program

#Id: 9657

#Unit 4. Cell Communication and Cell Signaling

Negative feedback regulation by MAP Kinase

activated MAP kinase triggers an increase in the expression of dual-specificity phosphatases (DUSPs), particularly DUSP6.