<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
The blank spaces in the task content should be filled with is; Three(3), atmosphere and ultraviolet rays of the sun.
<h3>What is Ozone?</h3>
Ozone is a trioxygen molecule; contained in the upper atmosphere with a sole aim of protecting biological life against ultraviolet rays of the sun. The ozone layer is however depleted to Oxygen molecule in the lower atmosphere.
Read more on ozone layer;
brainly.com/question/15444718
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Since fire is a chemical reaction, and oxygen is needed for that reaction, having a fire in a cave is a sure sign of the presence of oxygen.
