After the adenylyl cyclase reaction (which convert ATP into cyclic adenosine monophosphate-cAMP), cAMP level is directly increased. Next steps of PKA activation include:
• cAMP binding to regulatory subunits of PKA, as a result conformational change in the regulatory subunits of PKA is induced,
• catalytic subunits are detached and unleashed by regulatory subunits and as a result activated.
Answer: 50%
<span>Life on Earth appears to be on its way to extinction because of the carbon being pumped into our atmosphere.</span>
<span>Biologists reported that one in five species on Earth show signs of extinction, and unless urgent action is taken to save the planet’s biosphere, </span><span>scientists predict that 50% of species will be driven to </span>extinction by the year 2100.
<span>.</span>
Answer:
A proton gradient is generated by the transport of protons into the thylakoid lumen.
Protons move from the thylakoid lumen to the stroma through ATP synthase, producing ATP.
Explanation:
During photosynthesis, the environment is made acidic inside the lumen i.e. H⁺ are pumped into thylakoid lumen from stroma as a result of which more H⁺ are present in the thylakoid lumen as compared to stroma. It happens during light dependent reaction of photosynthesis. The concentration of H⁺ is already higher in lumen and transfer of more and more H⁺ from stroma increases the concentration of H⁺ even more leading to generation of a potential gradient. These H⁺ subsequently tend to move freely from lumen to stroma via "reverse pumps known as ATP synthase". The reason why these are known as reverse pumps is because pumps usually move particles from lower to higher concentration which is an active movement i.e. not natural so such movement requires energy. Naturally particles move from higher to lower concentration gradient until the concentration becomes equal on both the sides but pumps act opposite of this natural process and move particles from lower to higher concentration and utilize energy to do it. But here H⁺ are moving from higher to lower concentration which occurs naturally so ATP synthase rather than using energy tend to generate energy and this free energy is used to generate ATP from ADP & Pi (inorganic phosphate).
Answer:
The correct answer is - option B. They are small because they lack a nucleus.
Explanation:
Red blood cells or erythrocytes are specialized cell that produce in bone marrow and have specific role such as carrying oxygen from lungs to deliver it to the various organs and carry out carbon dioxide.
In mammals these cells lack cell organelles such as nucleus and mitochondria, a major factor that determined its smaller size. The size of RBC are move through narrow vessels throughout a organism because of its specific size and shape that provide it space for hemoglobin and allow to be flexible and bend to move through narrow vessels.
Thus, the correct answer is : option B. They are small because they lack a nucleus.
