What is the Biological importance of water Cohesion?
High Specific Heat:
The heat capacity of water is the amount of heat required to raise the temperature of one gram of water by one degree centigrade (15°C to 16°C), i.e., one calorie or 4.18 joules.
The high heat capacity of water means that a large increase in heat energy results in a relatively small temperature rise. This is because most of the energy is used in breaking hydrogen bonds which restrict the movement of molecules.
Due to this property a result the of water, hot water cools slowly while cool water gets hot slowly. the temperature of the earth and living bodies does not change quickly and e
stable.
High Heat of Vapourization:
High heat of vapourization is a measure of the heat energy required to vapourize a liquid. A relatively large amount of energy is needed to vapourize water. This is due to hydrogen bonding. The high heat of vapourization is excess body heat during sweating, panting transpiration, etc.
Cohesion and Adhesion:
Cohesion is the intermolecular att for animals and plants to get rid of similar molecules while adhesion is an attraction between dissimilar molecules. Water exhibits both cohesive and adhesive properties.
Due to the cohesion water molecules stick together, and remain in liquid bonding. Due to adhesive force water stick to the wall and flow together. The due to hydrogen in the container (such as because of the polar nature of water ).
Ionization:
It is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions. On ionization, water releases an equal number of H and OH ions. The state of equilibrium is maintained at 25°C.
Hydrophobic Exclusion:
It is the reduction of the contact area between water and hydrophobic substances when placed in water. This property of water plays an important role in maintaining the integrity of the lipid bilayer of all plasma membranes.'
Density and Freezing Properties:
The density of water decreases below 4°C, therefore, ice is lighter than water, and tends to float. It is the only substance whose solid form is less dense than its liquid because it has maximum hydrogen bonds. Ice insulates the water below it thus increasing the chances of survival of organisms during winter.
2.3 Carbohydrates
These are organic compounds, containing the elements of Carbon, Hydrogen, and Oxygen in the ratio of 1:2:1. Their general formula is C,(H, O),, where x and y are variable numbers. Carbohydrates are also known as hydrated carbon because the number of hydrogen and oxygen atoms is the same as in water.
Chemically they are polyhydroxy aldehyde ketone or complex substances.
Their chemistry is determined by aldehyde and ketone groups e.g. aldehydes are very easily oxidized and are powerful reducing agents. commonly called sugars or saccharides.
Classification:
There are three main classes of carbohydrates, that is monosaccharide, Oligosaccharide, and polysaccharide. Monosaccharides: (Gk. Mono: one, Saccharide: sweets or sugar) They are forms of carbohydrates that cannot be hydrolyzed into simple units.
monosaccharides
The Monosaccharides are small organic compounds made up of one sugar molecule, containing 3 to 7 carbon atoms. Theylovelysweet in taste and are easily soluble in water. All carbon atoms in a monosaccharide except one have a hydroxyl group while the remaining contain aldehyde or ketone.
The sugar with aldehyde group is called aldo sugar and with ketone group is called keto sugar. The specific formula for monosaccharides is C,(H, O), where, n is the number of carbon atoms in monosaccharides.
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