Answer:
option D is incorrect
Explanation:
the sedimentation coefficient is measured in Svedberg units named after the scientist Theodore Svedberg. the shape of the particle being measured in the ultracentrifuge is one of the factors that determines the sedimentation coefficient. the values are usually not additive as the sedimentation coefficient is based on the rate at which a particle sediments in an ultracentrifuge and not on the size. for example, the sedimentation coefficient of eukaryotic ribosome is 80S but is made up of the 60S large subunit and the 40S small subunit.
Answer:
- The lac operon can be activated by the binding of allolactose to the repressor protein, releasing it from DNA and thereby allowing for transcription to occur.
- In response to low glucose levels, cAMP is upregulated; the binding of cAMP to the cAMP receptor protein triggers the activation of the operon.
Explanation:
Lactose operon or lac operon (includes lacZ, lacY and lacA genes) is found in some bacteria and the products of its genes are involved in lactose metabolism. So, this operon is active (genes are transcribed) when lactose is present and glucose is absent (or at low level). The operon is regulated by the lac repressor which acts as a lactose sensor and catabolite activator protein (CAP) which acts as a glucose sensor.
When there is lactose (in the form of allolactose) lac repressor detects it and stops being repressor. This enables transcription.
CAP detects glucose (via cAMP) and activates transcription when glucose levels are low.
<span>(3) It cannot perform metabolic processes.</span>
