Answer:
B. A proton gradient drives the formation of ATP from ADP and inorganic phosphate via ATP synthase.
Explanation:
Light reaction of photosynthesis includes the splitting of water in the presence of sunlight and electron transfer from PSII to PSI via an electron transport system. During the transfer of electron through cytochrome of the electron transport system, the proton concentration gradient is generated across thylakoids. The proton concentration gradient is harvested to drive ADP phosphorylation by the catalytic site of ATP synthase accompanied by downhill movement protons through its proton channels.
In this kind of population, the make up of the population's gene pool will remain virtually the same as long as these conditions hold. In this kind of situation, no evolution can take place, all thing will remain the same. For evolution to occur, competition must exist.
A codon is a group of three mRNA bases while an anticodon is a group of three tRNA bases. For example AUC is a codon and UAG is an anticodon that matches it.
<h2>Scurvy </h2>
Explanation:
(a) Collagen is the major structural component of cartilage,bones and tendons
- The basic unit of collagen is tropocollagen and each tropocollagen consists of three coiled left handed polypeptide chains called α chains
- Generally each α chain consists of a repeating tripeptide sequence called: G-X-Y
- Here G represents glycine; X represents proline and Y represents hydroxyproline
- Rigidity of collagen molecule is due to presence of proline and hydroxyproline
- Hydroxylation of proline is catalysed by prolyl hydroxylase enzyme which use ascorbate,α ketoglutarate and oxygen
- α ketoglutarate is oxidatively decarboxylated to form carbon dioxide and succinate
- Sequence of events leading from a dietary vitamin C deficiency to symptoms such as bruising and breakdown of supporting tissues includes: tissue levels of ascorbic acid is low; enzyme prolyl hydroxylase is inactive; proline is not hydroxylated; the triple helix is inadequately stabilized; collagen breaks down; defects in tissues that depend on collagen
; tissues that depend on collagen are subject to breakdown and bruising
(b) Sailors are no longer susceptible to scurvy because fresh fruits which are the source of vitamin C source are available now
British sailors called "limeys" to this day,this term reflects the British navy's use of limes
