Three of the functions of proteins are as antibodies, as enzymes and as messengers. As antibodies, they protect the cells from diseases ie they fight diseases. As enzymes, they regulate the chemical reactions within cells, and thirdly they transmit signals as messengers such as hormones do in co-ordinating biological processes. Proteins are so diverse because of their unique 3-D structures which their polymers form from the 20 amino acids available as their building blocks.
Answer: It is an exothermic process because heat energy is absorbed by the water as the NaOH(s) dissolves in it.
Explanation:
Endothermic reaction : It is a type of chemical reaction where the energy is absorbed from the surrounding. In the endothermic reaction, the reactant are less than the energy of product. In endothermic reaction, the change in enthalpy is, positive
Exothermic reaction : It is a type of chemical reaction where the energy is released into the surrounding. In the exothermic reaction, the energy of reactant are more than the energy of product. In exothermic reaction, the change in enthalpy is, negative.
Thus as energy is absorbed by water, which has been released by NaOH, the process is exothermic.
Quartz is a substance because the material has uniform properties throughout and is held together via chemical bonds.