Living things are made of types of molecules, known as macromolecules.
There are four major classes of biological macromolecules:
carbohydrates
lipids
proteins
nucleic acids
Each of these types of macromolecules performs a wide array of important functions within the cell; a cell cannot perform its role within the body without many different types of these crucial molecules. In combination, these biological macromolecules make up the majority of a cell’s dry mass. (Water molecules make up the majority of a cell’s total mass.) All the molecules both inside and outside of cells are situated in a water-based (i.e., aqueous) environment, and all the reactions of biological systems are occurring in that same environment.
 
        
             
        
        
        
Answer:
16.66 %
Explanation:
The receptors that are bound with the ligand can be calculated by the formula as follows:
Kd = [R] [L]/[RL]
Here, Kd is dissociation constant = 1.5 mM
R is free receptor concentration = 10 mM
L is free ligand concentration = 2.5 mM
The values needs to be constitute to find the percentage  of receptors that are bound to ligand.
Put all the values
1.5 = 10 × 2.5 / RL or RL = 25 /1.5
So RL = 16.66
Hence 16.66 % of receptor is bound to substrate.
Thus, the answer is 16.66%
 
        
             
        
        
        
Answer: D. I, II, III, IV, V, and VI
Explanation:
Oxygen is recquired for cellular respiration and break down nutrients like sugar to create ATP. Organisms from all kingdoms like Bacteria, Archea, Plants, Protists, animals and fungi can use cellular respireation.