The 3D structure of the complete Escherichia coli ribosome with bound mRNA and tRNAs revealed that the very amino terminus of one protein (L27) does reach into the active site. This finding suggested a role for this protein in catalysis. To test this possibility, the nine amino acids at the L27 amino terminus that were in close proximity to the active site were eliminated by mutation. The following possible outcomes were found to be correct as

A. The resulting cells produced ribosomes with reduced but detectable peptidyl transferase activity

B. Region of the L27 protein contributes to peptidyl transferase activity

C. The mutant ribosomes, didn’t synthesised wildtype levels of cells

D. Vast majority of this increase in peptide bond formation is retained, even without the presence of L27 in the active site

E. The most likely role for L27 is to correctly position one or more of the RNA components of the active site

#Question id: 5074

#Unit 5. Developmental Biology

The "mid-blastula transition" is the point in development when:

#Question id: 10152

#Unit 6. System Physiology – Plant

Rubisco catalyzes both the carboxylation and the oxygenation of ribulose 1,5-bisphosphate, the oxygenase activity of rubisco causes partial loss of the carbon fixed by the Calvin–Benson cycle, to avoid loss a reaction takes place such as photorespiration, The following statements about photorespiration.

a.) To avoid drain of carbon out of the Calvin–Benson cycle is metabolized through the C2 oxidative photosynthetic carbon cycle

b.) In photorespiration involves chloroplasts, leaf peroxisomes, and mitochondria

c.) During oxygenation process Rubisco fixes oxygen at high temperature

d.) One of the rection of the C2 cycle is Glycine converted into the serine is takes place in peroxisome

Which of following from above combination is CORRECT?

#Question id: 28557

#Unit 5. Developmental Biology

The emerging column of cells topples over called___

#Question id: 29045

#Unit 10. Ecological Principles

Surface Temperatures Reflect the Difference between__

#Question id: 10405

#Unit 6. System Physiology – Plant