To extend elongation into the transcription unit, a kinase complex called P-TEFb is required. P-TEFb contains the CDK9 kinase, which is a member of the kinase family that controls the cell cycle. P-TEFb acts on the CTD to phosphorylate it further on serine 2 of the heptapeptide repeat.

TLS Online TPP Program

#Id: 6533

#Unit 7. System Physiology – Animal

The entry of glucose into pancreatic β cells is mediated by the GLUT2 glucose transporter Because the Km for glucose of GLUT2 is 20 mM, a rise in extracellular glucose from 5 mM, causes a proportional increase in the rate of glucose entry

TLS Online TPP Program

#Id: 6102

#Unit 3. Fundamental Processes

5-bromouracil induces transitions in both directions, A:T ↔ G:C Deamination of adenine results in A:T → G:C transitions and the deamination of cytosine produces G:C → A:T transitions, so nitrous acid induces transitions in both directions

TLS Online TPP Program

#Id: 8977

#Unit 11. Evolution and Behavior

Molecular clock - The concept of a steady rate of change in DNA sequences over time. 

TLS Online TPP Program

#Id: 10119

#Unit 6. System Physiology – Plant

In plants that produce indole glucosinolate defense compounds, IAA can also be synthesized from tryptophan via a pathway with indole acetonitrile as an intermediate

TLS Online TPP Program

#Id: 8208

#Unit 2. Cellular Organization

There are 4 paths from different sources feed substances into lysosomes for digestion:

• Endocytosis

• Phagocytosis

• Macropinocytosis

• Autophagy