B cells migrate to the lymphoid follicles. They are directed there by chemokine interactions between CXCL13, which is secreted by follicular dendritic cells (FDCs).

TLS Online TPP Program

#Id: 8032

#Unit 1. Molecules and their Interaction Relevant to Biology

Ornithine and citrulline, which are not found in proteins, are intermediates in the biosynthesis of arginine and in the urea cycle.

TLS Online TPP Program

#Id: 3111

#Unit 3. Fundamental Processes

The replicated region appears as a replication bubble within the nonreplicated DNA. 

TLS Online TPP Program

#Id: 3015

#Unit 3. Fundamental Processes

E. coli SSB- Note that this protein is not a DNA-unwinding protein; its function is to stabilize DNA that is already in the single-stranded condition

TLS Online TPP Program

#Id: 5272

#Unit 7. System Physiology – Animal

Membrane ion channels that play important roles in generation of the action potential:

T (transient) channels 

L (long-lasting) channels

Voltage gated potassium ion channel

TLS Online TPP Program

#Id: 7444

#Unit 5. Developmental Biology

gp 80 – form tight aggregate