Sand is granular and coarse meaning that water and nutrients can flow through it quite easily. Clay on the other hand has very fine particles that cling together to form a waterproof substance which traps/ stops any nutrients or water from moving down. Clay's also quite difficult for plants to get their roots into. Silt has a texture between clay and sand, meaning that it is the ideal substance as it allows the best water and nutrition movement in the soil. Most plants will grow best in silt, but there are some plants who are more adapted to living in sand (e.g. Marram grass) or clay.
a. phosphate group, sugar, nitrogen base.
b. if it is DNA- deoxyribose sugar and if it is RNA- ribose sugar
c.Nitrogen base
d. Adenine, Gaunine, cytosine, Thymine.
The answer is; catalyst
These proteins are called enzymes. They work by lowering the activation energy of reactants and hence speed up the biochemical reaction. They are not affected in the process hence one enzyme molecule can catalyze many reactions. An example of such an enzyme is carbonic anhydrase that enables carbon dioxide to dissolve in blood plasma as carbonic acid.