The hemoglobin holoenzyme (active enzyme) is a complex of an iron ion and 4 subunits- 2 hemoglobin alpha and two hemoglobin beta. People with sickle cell disease have mutated beta hemoglobins. The mutation is a single nucleotide exchange, that changes the 6th amino acid of protein primary struture - a Glutamic acid into Valine. This one alteration changes the tree dimentional structure of hemoglobin beta so, that it forms lond fibres that disrupt the normal circular form of the red blood cells.
Flowering plants are the most successful land plants because theri seeds are protected in fruits
Answer:
Scientific theories can never be proven true beyond all doubt; they can only be supported by a wide body of evidence. Only one of the statements that follow uses the term theory in its correct, scientific sense.
Explanation:
<h2>False is the answer </h2>
Explanation:
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You absorb vitamin d from sunlight shining on your skin.
Vitamin d can help the absorption of calcium, which is capable for strengthening your bones and teeth.
Therefore if u r lacking of vitamin d, your bones and teeth may be soft, and especially among children, you may get ricket, where the legs are bent outwards.
