The question is incomplete. The complete question is attached below.
Answer:
1. DNA is the polymer of deoxyribonucleotides that contain the nitrogenous base, pentose sugar and phosphate group. The phosphate is attached with the 3 C position of the deoxyribose sugar. This leads to teh formation of phosphodiester bond.
2. The DNA backbone consists of phosphate and sugar. The nitrogenous bases are inserted inside the DNA molecule. These nitrogenous bases are linked together by the hydrogen bonds.
3. The adenine binds requires two hydrogen bonds to bind with thymine. This provide complementary nature to the DNA molecule. Uracil is present instead of thymine in RNA .
4. The guanine binds requires three hydrogen bonds to bind with cytosine. More amount of energy is required to break their bonds.
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).
