The human immunodeficiency virus (HIV) that causes the disease known as aids selectively infects helper T cells (CD4+).
This retrovirus also infects macrophages and dendritic cells. When CD4+ T cell numbers decrease below a critical level (due to the killing of this cells with different mechanisms), cell-mediated immunity is lost. As a result, the body becomes progressively more susceptible to infections, leading to the development of AIDS.
<span> HIV can be transmitted only via body fluids like blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, which means that people usually get or transmit HIV through sexual behaviours and use of the needle. For HIV infection, these fluids must come in direct contact with a mucous membrane or damaged tissue. Another way is to be directly injected into the bloodstream (from a needle for example).</span>
<span>Most people's urine is darker in the morning as the kidneys work hard during the night to remove impurities and the urine is more concentrated.</span>
Answer:
The correct answer is c) They are used to form ATP by chemiosmosis
Explanation:
In cellular respiration, glucose is oxidized into carbon dioxide and water and converts into NADH a FADH₂ during glycolysis and Kreb cycle. Then these reduced molecules are used to provide the source of electrons during chemiosmosis.
This transfer of electron to electron transport chain brings the conformation change in proteins that helps in transport of H⁺ions across the inner membrane of mitochondria. This transport of ions increase the proton gradient in the membrane.
So to equalize the proton gradient H⁺ moves towards the matrix through ATPase which allows the formation of ATP from ADP. Therefore the right answer is c) They are used to form ATP by chemiosmosis.
