Biological Molecules and
Biochemical Processes
Water
A water molecule has two hydrogen atoms and one oxygen atom. The structure is bent
because the oxygen atom carries two pairs of unshared electrons. Water helps break down
food and keep organisms cool. Water forms the basis of life on Earth as it is the medium in
which all the metabolic reactions happen in the cells. The bonding is covalent since the
oxygen atoms attracts electrons more strongly than the hydrogen atoms. The attraction
between individual water molecules creates a hydrogen bond. Cohesion and adhesion are
both properties of water. Cohesion is when water likes to stick to stick to itself and adhesion
is when water likes to stick to other things. Cohesion allows the development of surface
tension. This lets objects denser than water to float on the surface. Adhesion lets water to
bond with other molecules so water can stick to windows and other substances. These
properties allow fluids to be transported against the force of gravity. Water can take a lot of
energy to heat it. Water must absorb 4,18 Joules of heat to increase by 1C. That is more
heat compared to other substances, so more heat is needed to raise the temperature.
Water’s high heat capacity results from its hydrogen bonds. When heat is absorbed,
hydrogen bonds are broken, and water molecules can move freely. When the temperature
decreases hydrogen bonds are formed and release a big amount of energy. Water has a high
surface tension ranging from 72mN/m at room temperature. This allows objects to float on
water without becoming submerged. This also helps plants to transport water from roots to
leaves. Water has high density in liquid form with 997Kg/m3. Ice floats on top of water
because of it has a lower density. The density of water affects its temperature regulation of
aquatic environment giving a stable habitat for organisms. The reaction equation for water
is 2H2+O2=2H2O
, Carbohydrates
Their molecules consist of carbon, hydrogen, and oxygen. There are three types of
carbohydrates: monosaccharides, disaccharides, and polysaccharides. The C:H:0 ratio in
carbohydrates is 1:2:1. They are an energy source and helps regulate blood glucose and
insulin metabolism and take part in cholesterol and triglycerides metabolism.
Monosaccharides
It is known as a simple sugar and includes glucose, galactose, and fructose and are sweet-
tasting and soluble and forms crystals. The general formula is (CH20)n2. Monosaccharides
combine through glycosidic bonds (covalent bonds that link ring-shaped sugar molecules
with other molecules) to form larger carbohydrates. Glycosidic bonds form by a
condensation reaction between an amine of one molecule and the anomeric carbon of the
sugar.
Disaccharides
They are formed when two monosaccharides join.
Biochemical Processes
Water
A water molecule has two hydrogen atoms and one oxygen atom. The structure is bent
because the oxygen atom carries two pairs of unshared electrons. Water helps break down
food and keep organisms cool. Water forms the basis of life on Earth as it is the medium in
which all the metabolic reactions happen in the cells. The bonding is covalent since the
oxygen atoms attracts electrons more strongly than the hydrogen atoms. The attraction
between individual water molecules creates a hydrogen bond. Cohesion and adhesion are
both properties of water. Cohesion is when water likes to stick to stick to itself and adhesion
is when water likes to stick to other things. Cohesion allows the development of surface
tension. This lets objects denser than water to float on the surface. Adhesion lets water to
bond with other molecules so water can stick to windows and other substances. These
properties allow fluids to be transported against the force of gravity. Water can take a lot of
energy to heat it. Water must absorb 4,18 Joules of heat to increase by 1C. That is more
heat compared to other substances, so more heat is needed to raise the temperature.
Water’s high heat capacity results from its hydrogen bonds. When heat is absorbed,
hydrogen bonds are broken, and water molecules can move freely. When the temperature
decreases hydrogen bonds are formed and release a big amount of energy. Water has a high
surface tension ranging from 72mN/m at room temperature. This allows objects to float on
water without becoming submerged. This also helps plants to transport water from roots to
leaves. Water has high density in liquid form with 997Kg/m3. Ice floats on top of water
because of it has a lower density. The density of water affects its temperature regulation of
aquatic environment giving a stable habitat for organisms. The reaction equation for water
is 2H2+O2=2H2O
, Carbohydrates
Their molecules consist of carbon, hydrogen, and oxygen. There are three types of
carbohydrates: monosaccharides, disaccharides, and polysaccharides. The C:H:0 ratio in
carbohydrates is 1:2:1. They are an energy source and helps regulate blood glucose and
insulin metabolism and take part in cholesterol and triglycerides metabolism.
Monosaccharides
It is known as a simple sugar and includes glucose, galactose, and fructose and are sweet-
tasting and soluble and forms crystals. The general formula is (CH20)n2. Monosaccharides
combine through glycosidic bonds (covalent bonds that link ring-shaped sugar molecules
with other molecules) to form larger carbohydrates. Glycosidic bonds form by a
condensation reaction between an amine of one molecule and the anomeric carbon of the
sugar.
Disaccharides
They are formed when two monosaccharides join.
