UNIT 10 A
Write your assignment here…..
A: Understand the structure and function of biological molecules and their
importance in maintaining biochemical processes
Water
Water is a polar molecule made of 1 oxygen atom and 2 hydrogen atoms (H2O) bonded
together with a covalent bond which means they share their electrons. Due to water being a
polar molecule this causes hydrogen bonds to form between water molecules and forms
cohesive forces. Cohesion is the attraction of molecules to other molecules of the same kind,
water has strong cohesive forces thanks to their ability to form hydrogen bonds with each
other, therefore water molecules at the surface form stronger interactions with the neighbors
they do have. The charges of the atoms in water are partial and are shown with the delta
symbols [1]. This is because the electrons are not shared evenly as oxygen is more
electronegative than hydrogen, therefore oxygen has a greater pull on the electrons than the
hydrogen making it a polar molecule. Water is structured with thousands of molecules joined
with hydrogen bonds[2] where the delta + (The hydrogen molecule) bonds with the delta –
(The oxygen molecule). This gives water a high specific heat capacity which means it takes a
lot of energy to raise its temperature by just 1 degree and allows water to remain as a liquid
for a wider range of temperatures.
Due to water being a polar molecule this means it can act as a solvent to other polar molecules
for example salt, the partially negative oxygen atoms of the water molecules face and
surround the sodium cations. At the same time, the partially positive hydrogen atoms of other
water molecules face and surround chlorine anions on the surface of each salt crystal. This
causes the cations and anions to separate, breaking the ionic bonds.
1
,Another property of water is cohesion and adhesion. Cohesion
is when water molecules ‘stick’ together instead of spreading
apart due to the hydrogen bonds between the molecules
forming and breaking quickly eg- a water droplet. Adhesion is
when water molecules form hydrogen bonds with other
molecules as well eg- when the water droplet is stuck to a pine
needle. These two properties together cause the phenomenon
of capillary action, this is when the adhesion to the walls of a
vessel is stronger than the cohesive forces between the water
molecules, this makes the water travel against gravity in an
upward motion within a vessel. These properties also allow
things to float on top of water e.g. pond skaters and debris
due to surface tension.
[3]
The importance of water in the body:
- as a transport of molecules
- acting as a medium for chemical reactions
- regulating pH
- temperature regulator
- electrolyte balance
Due to its polar structure, water can form hydrogen bonds which gives the unique functions
and properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion
and density Water is one of the most important molecules in the body, it's an excellent
transport medium as it stays in a liquid state over a large temperature range which is useful
within the cytoplasm of a cell. It helps regulate the temperature within the body and also
regulates pH levels. This is done by water leaving the body as sweat, which is evaporated and
cools the body effectively. Capillary action helps the movement of water in and out of your
cellular structure that deposits vitamins, nutrients, and vital blood plasma. Without this flow,
your body's cells would not rehydrate and vital communication between your brain and body
would slow.
Carbohydrates
Carbohydrates are very important for the body to gain energy. They are vital for every living
organism to act as an energy source and store, and are used for structure. Carbohydrates
contain the elements : carbon, oxygen and hydrogen, and the general formula is Cn(H2O)n.
Using carbohydrates as an energy source prevents important proteins from being broken down
for energy in animals.
Monosaccharides are the simplest carbohydrates and the monomer of the molecule, when
monosaccharides join together they will eventually form longer, more complex carbohydrates.
All monosaccharides are soluble in water, form crystals and taste sweet, they can be classified
according to the number of carbon atoms they contain eg. triose, pentose and hexose. One of
the most common monosaccharides is glucose as it is a simple sugar, there are two types of
glucose and they both have different structures and functions within the body. Alpha glucose is
used in respiration in plants and animals as the active sites on the enzymes used to speed up
the respiration are complementary to the shape of alpha glucose. They are also the monomer
unit in starch and as a result of the bond angles in the linkage, starch forms a spiral structure.
Beta glucose is the monomer unit in cellulose used to build cell walls and found in fibre as part
of a balanced diet. As a result of the bond angles in beta glucoses linkage it mostly forms a
linear chain.
2
, [4]
Disaccharides are formed when two monosaccharides join together in a condensation reaction,
a condensation reaction is when water is removed from the two molecules in order to form a
larger molecule. During this reaction a covalent 1,4 glycosidic bond is formed and this can only
be broken by a hydrolysis reaction when water is added back in to make two monosaccharides.
Disaccharides are often found in many foods and can be added as sweeteners like sucrose is
used as table sugar and the most common for human consumption. The three most common
disaccharides are : maltose, lactose and sucrose.
[5]
Polysaccharides are formed when a large number of monosaccharides join together with
glycosidic bonds, they have this name as polysaccharides are polymers made of many
repeating units of monosaccharides. The most important polysaccharides are: amylose,
amylopectin, glycogen and cellulose.
Carbohydrates are very important within the body as they are used for the digestion process to
produce Adenosine triphosphate (ATP) which is the body’s chemical energy and vital in all
bodily functions. The production of ATP is achieved by the oxidation of glucose molecules. Due
to glucose existing as a single molecule or a monosaccharide, its molecular structure exists as
a six carbon molecule with twelve hydrogen molecules attached and six oxygen
molecules(C6H12O6). Fructose, which is another monosaccharide, is also a six carbon
molecule with 12 hydrogen and 6 oxygen molecules attached. However, the structure of
fructose is different from glucose in the arrangement of the molecules. Fructose comes from
fruit and is sweeter than glucose. Therefore the molecular structure of these carbohydrate
molecules has an effect on the taste.
The CHO ratio in carbohydrates is 1:2:1,
[23]
lipids also have a similar CHO ratio as
carbohydrates but the ratio is 1:2:very
few O atoms within the molecule as
shown below.
[24]
3
Write your assignment here…..
A: Understand the structure and function of biological molecules and their
importance in maintaining biochemical processes
Water
Water is a polar molecule made of 1 oxygen atom and 2 hydrogen atoms (H2O) bonded
together with a covalent bond which means they share their electrons. Due to water being a
polar molecule this causes hydrogen bonds to form between water molecules and forms
cohesive forces. Cohesion is the attraction of molecules to other molecules of the same kind,
water has strong cohesive forces thanks to their ability to form hydrogen bonds with each
other, therefore water molecules at the surface form stronger interactions with the neighbors
they do have. The charges of the atoms in water are partial and are shown with the delta
symbols [1]. This is because the electrons are not shared evenly as oxygen is more
electronegative than hydrogen, therefore oxygen has a greater pull on the electrons than the
hydrogen making it a polar molecule. Water is structured with thousands of molecules joined
with hydrogen bonds[2] where the delta + (The hydrogen molecule) bonds with the delta –
(The oxygen molecule). This gives water a high specific heat capacity which means it takes a
lot of energy to raise its temperature by just 1 degree and allows water to remain as a liquid
for a wider range of temperatures.
Due to water being a polar molecule this means it can act as a solvent to other polar molecules
for example salt, the partially negative oxygen atoms of the water molecules face and
surround the sodium cations. At the same time, the partially positive hydrogen atoms of other
water molecules face and surround chlorine anions on the surface of each salt crystal. This
causes the cations and anions to separate, breaking the ionic bonds.
1
,Another property of water is cohesion and adhesion. Cohesion
is when water molecules ‘stick’ together instead of spreading
apart due to the hydrogen bonds between the molecules
forming and breaking quickly eg- a water droplet. Adhesion is
when water molecules form hydrogen bonds with other
molecules as well eg- when the water droplet is stuck to a pine
needle. These two properties together cause the phenomenon
of capillary action, this is when the adhesion to the walls of a
vessel is stronger than the cohesive forces between the water
molecules, this makes the water travel against gravity in an
upward motion within a vessel. These properties also allow
things to float on top of water e.g. pond skaters and debris
due to surface tension.
[3]
The importance of water in the body:
- as a transport of molecules
- acting as a medium for chemical reactions
- regulating pH
- temperature regulator
- electrolyte balance
Due to its polar structure, water can form hydrogen bonds which gives the unique functions
and properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion
and density Water is one of the most important molecules in the body, it's an excellent
transport medium as it stays in a liquid state over a large temperature range which is useful
within the cytoplasm of a cell. It helps regulate the temperature within the body and also
regulates pH levels. This is done by water leaving the body as sweat, which is evaporated and
cools the body effectively. Capillary action helps the movement of water in and out of your
cellular structure that deposits vitamins, nutrients, and vital blood plasma. Without this flow,
your body's cells would not rehydrate and vital communication between your brain and body
would slow.
Carbohydrates
Carbohydrates are very important for the body to gain energy. They are vital for every living
organism to act as an energy source and store, and are used for structure. Carbohydrates
contain the elements : carbon, oxygen and hydrogen, and the general formula is Cn(H2O)n.
Using carbohydrates as an energy source prevents important proteins from being broken down
for energy in animals.
Monosaccharides are the simplest carbohydrates and the monomer of the molecule, when
monosaccharides join together they will eventually form longer, more complex carbohydrates.
All monosaccharides are soluble in water, form crystals and taste sweet, they can be classified
according to the number of carbon atoms they contain eg. triose, pentose and hexose. One of
the most common monosaccharides is glucose as it is a simple sugar, there are two types of
glucose and they both have different structures and functions within the body. Alpha glucose is
used in respiration in plants and animals as the active sites on the enzymes used to speed up
the respiration are complementary to the shape of alpha glucose. They are also the monomer
unit in starch and as a result of the bond angles in the linkage, starch forms a spiral structure.
Beta glucose is the monomer unit in cellulose used to build cell walls and found in fibre as part
of a balanced diet. As a result of the bond angles in beta glucoses linkage it mostly forms a
linear chain.
2
, [4]
Disaccharides are formed when two monosaccharides join together in a condensation reaction,
a condensation reaction is when water is removed from the two molecules in order to form a
larger molecule. During this reaction a covalent 1,4 glycosidic bond is formed and this can only
be broken by a hydrolysis reaction when water is added back in to make two monosaccharides.
Disaccharides are often found in many foods and can be added as sweeteners like sucrose is
used as table sugar and the most common for human consumption. The three most common
disaccharides are : maltose, lactose and sucrose.
[5]
Polysaccharides are formed when a large number of monosaccharides join together with
glycosidic bonds, they have this name as polysaccharides are polymers made of many
repeating units of monosaccharides. The most important polysaccharides are: amylose,
amylopectin, glycogen and cellulose.
Carbohydrates are very important within the body as they are used for the digestion process to
produce Adenosine triphosphate (ATP) which is the body’s chemical energy and vital in all
bodily functions. The production of ATP is achieved by the oxidation of glucose molecules. Due
to glucose existing as a single molecule or a monosaccharide, its molecular structure exists as
a six carbon molecule with twelve hydrogen molecules attached and six oxygen
molecules(C6H12O6). Fructose, which is another monosaccharide, is also a six carbon
molecule with 12 hydrogen and 6 oxygen molecules attached. However, the structure of
fructose is different from glucose in the arrangement of the molecules. Fructose comes from
fruit and is sweeter than glucose. Therefore the molecular structure of these carbohydrate
molecules has an effect on the taste.
The CHO ratio in carbohydrates is 1:2:1,
[23]
lipids also have a similar CHO ratio as
carbohydrates but the ratio is 1:2:very
few O atoms within the molecule as
shown below.
[24]
3
