The dissociation constant Kd for a receptor-ligand complex is

a. a measure of the affinity of the receptor for the ligand.

b. the concentration of the ligand at which half of the receptors contain bound ligand.

c. a measure of the time it takes for a ligand to be converted to a product.

d. equal to koff/kon 

TLS Online TPP Program

#Question id: 15724

#Unit 11. Evolution and Behavior

Neo-Lamarckism includes several theories based on the old idea of inheritance of modifications acquired during an organism’s lifetime. In a famous experiment done by,

TLS Online TPP Program

#Question id: 7139

#Unit 5. Developmental Biology

If apoptosis in the developing limb were blocked, what feature of a normal limb would not form?

TLS Online TPP Program

#Question id: 29439

#Unit 6. System Physiology – Plant

Nitrogenase, a complex metal containing enzyme is involved in conversion of N2 to NH3•

a. Nitrogenase is composed of two component proteins

b. Nitrogenase is a complex consisting of the MoFe protein (dinitrogenase or component I) a heterotetramer

c. Nitrogenase is a complex consisting of the MoFe protein (dinitrogenase or component I) a heterotetramer

d. Fe protein (dinitrogenase reductase or component II) a heterodimer

Which of the combination of above statement about Nitrogenase is INCORRECT

TLS Online TPP Program

#Question id: 34133

#Unit 7. System Physiology – Animal

Which of the following would be least likely to be seen 14 days after a rat is injected with a drug that kills all of its pancreatic B cells?

TLS Online TPP Program

#Question id: 4043

#Unit 3. Fundamental Processes

In the process of creating a trp operon mutant, the UGG codons within the leader sequence were accidentally deleted. Which of the following would be a likely observation in the transcription assays? ___

A. RNA polymerase cannot bind to the promoter. 

B. The operon is permanently inhibited. 

C. Attenuation would be impaired. 

D. Termination would be triggered. 

E. No tryptophan would be made.