Answer:
A glance of earth taken from space will depict it blue. This blue colour is actually water, the major part of the earth is covered with water. We need water for almost everything, for example- drinking, bathing, cooking etc and therefore we should know about the properties of water. 65 % human body is composed of water. Water is essential for the survival of life on earth. Water is distributed unevenly on the earth’s surface. It forms a major solvent and dissolves almost every polar solute. So let us have a look at its properties.
Physical properties of water : Water is a colourless and tasteless liquid. The molecules of water have extensive hydrogen bonds resulting in unusual properties in the condensed form. This also leads to high melting and boiling points. As compared to other liquids, water has a higher specific heat, thermal conductivity, surface tension, dipole moment etc. These properties form the reason for its significance in the biosphere. Water is an excellent solvent and therefore it helps in the transportation of ions and molecules required for metabolism. It has a high latent heat of vaporization which helps in the regulation of body temperature
Chemical properties of water: Amphoteric nature:
Water can act as both acid and base, which means that it is amphoteric in nature.
Example:
Acidic Behaviour: H2O(l)+NH3(aq) ⇌ H3O+(aq)+NH+4(aq)
Basic Behavior: H2O(l)+H2S(aq) ⇌ H3O+(aq)+HS−(aq)
Redox reactions:
Electropositive elements reduce water to hydrogen molecule. Thus water is a great source of hydrogen. Let us see an example in this case:
2H2O(l)+2Na(s)→2NaOH(aq)+H2(g)
During the process of photosynthesis, water is oxidized to O2. As water can be oxidized and reduced, it is very useful in redox reactions.
Hydrolysis reaction
Water has a very strong hydrating tendency due to its dielectric constant. It dissolves many ionic compounds. Some covalent and ionic compounds can be hydrolyzed in water.
Explanation:
Answer:
Plants exchange two gases in the atmosphere i. e. oxygen and carbondioxide. Carbondioxide is entered into the plant body through small opening called stomata which are present on the surface of leaves. Carbondioxode is used as a raw material in the process of photosynthesis. Oxygen is produced in the end of photosynthesis process and releases in the atmosphere.
I would go with the first option
Answer: D. some components of the cycle are used as building blocks for certain anabolic pathways.
Explanation:
The citric acid cycle or Kreb's cycle is the part of the cellular respiration. It is a sequence of chemical reaction which is used by all the aerobic organisms so as to store energy by the process of acetyl CoA oxidation derived by the process of fats, proteins and carbohydrates into forms like carbon dioxide and adenosine triphosphate (ATP).
The acetyl CoA is used in the process of synthesis of fatty acids. The citrate is used for the synthesis of cholestrol. The oxaloacetate and alpha ketogluterate are used for the synthesis of aminoacids. Succinyl CoA is used for the synthesis of poryphrins and fatty acids.
