Carbohydrates
Carbohydrates is a type of food group used for energy, one main example
of carbohydrates is starch, starch is made up of glucose molecules linked
together. There are two types of glucose known as isomers and there
called, beta glucose and alpha glucose. Both isomers of glucose have a 5-
carbon ring structure, and both have 1st carbon atom bonded to an
oxygen atom, plus a hydrogen atom and a hydroxyl (OH) group. However,
the alpha glucose has the hydrogen atom attached to carbon 1 above the
OH, whereas beta glucose has it below the OH. Which can be seen in this
diagram below which can be accessed at
https://alevelbiology.co.uk/notes/biologicalcompounds/
Alpha glucose is used in respiration for both plants and animals. This is
because the enzymes used to speed up the respiration have a
complementary to the shape of the alpha glucose and not beta glucose.
Beta glucose however is a building block for cellulose which provides very
good structural support to plant cells.
Carbohydrates are made up of 3 atoms, Carbon (C), Hydrogen (H),
Oxygen (O). For example, glucose is C6H12O6
Condensation reaction
When two glucose molecules undergo a condensation reaction, they
form disaccharides like maltose, lactose, or sucrose. During a
condensation reaction one glucose molecule will loses an OH otherwise
known as a carboxyl group,
whereas the other glucose
molecule will lose one
hydrogen, ultimately
forming one water molecule
(H2O). An example of this
reaction is shown below,
, where two alpha glucose molecules undergo a condensation reaction
and form maltose. This can be accessed from the website
https://studymind.co.uk/notes/carbohydrates-disaccharides/
One example of a polysaccharide would be starch, starch is primarily
used for storing energy in cells for both plants and animals, for
example, in humans’ glucose is used to store energy. Starch contains
amylose, amylose is a” long chain of α-glucose monomers joined by
1,4-glycosidic bonds. The chain coils in a spiral shape, held together by
hydrogen bonds. This shape makes starch well suited to energy storage
as it is compact, so takes up little space in the cell, and not very
soluble in water, so does not affect the water potential of the cell”-
https://www.mytutor.co.uk/answers/31664/A-Level/Biology/Describe-
the-structure-of-starch-How-does-this-structure-make-starch-well-
suited-for-energy-storage/ ( Molly S)
Another example of a polysaccharide is cellulose, in cellulose, alternate
glucose monomers are rotated 180 degrees, allowing for an overall
straight shape in the molecule, allowing structural conformity and
rigidity, this helps cellulose give its structural benefits.
Proteins
Proteins are a diverse group of large and complex polymer molecules,
made up of long chains of amino acids. Proteins are the main
component of body tissues, such as muscle, skin, ligaments and hair.
Proteins also make up all enzymes/biological catalysts and antibodies
and make up many receptors and hormones. The main atoms in a
protein are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and
sulphur (S).
Carbohydrates is a type of food group used for energy, one main example
of carbohydrates is starch, starch is made up of glucose molecules linked
together. There are two types of glucose known as isomers and there
called, beta glucose and alpha glucose. Both isomers of glucose have a 5-
carbon ring structure, and both have 1st carbon atom bonded to an
oxygen atom, plus a hydrogen atom and a hydroxyl (OH) group. However,
the alpha glucose has the hydrogen atom attached to carbon 1 above the
OH, whereas beta glucose has it below the OH. Which can be seen in this
diagram below which can be accessed at
https://alevelbiology.co.uk/notes/biologicalcompounds/
Alpha glucose is used in respiration for both plants and animals. This is
because the enzymes used to speed up the respiration have a
complementary to the shape of the alpha glucose and not beta glucose.
Beta glucose however is a building block for cellulose which provides very
good structural support to plant cells.
Carbohydrates are made up of 3 atoms, Carbon (C), Hydrogen (H),
Oxygen (O). For example, glucose is C6H12O6
Condensation reaction
When two glucose molecules undergo a condensation reaction, they
form disaccharides like maltose, lactose, or sucrose. During a
condensation reaction one glucose molecule will loses an OH otherwise
known as a carboxyl group,
whereas the other glucose
molecule will lose one
hydrogen, ultimately
forming one water molecule
(H2O). An example of this
reaction is shown below,
, where two alpha glucose molecules undergo a condensation reaction
and form maltose. This can be accessed from the website
https://studymind.co.uk/notes/carbohydrates-disaccharides/
One example of a polysaccharide would be starch, starch is primarily
used for storing energy in cells for both plants and animals, for
example, in humans’ glucose is used to store energy. Starch contains
amylose, amylose is a” long chain of α-glucose monomers joined by
1,4-glycosidic bonds. The chain coils in a spiral shape, held together by
hydrogen bonds. This shape makes starch well suited to energy storage
as it is compact, so takes up little space in the cell, and not very
soluble in water, so does not affect the water potential of the cell”-
https://www.mytutor.co.uk/answers/31664/A-Level/Biology/Describe-
the-structure-of-starch-How-does-this-structure-make-starch-well-
suited-for-energy-storage/ ( Molly S)
Another example of a polysaccharide is cellulose, in cellulose, alternate
glucose monomers are rotated 180 degrees, allowing for an overall
straight shape in the molecule, allowing structural conformity and
rigidity, this helps cellulose give its structural benefits.
Proteins
Proteins are a diverse group of large and complex polymer molecules,
made up of long chains of amino acids. Proteins are the main
component of body tissues, such as muscle, skin, ligaments and hair.
Proteins also make up all enzymes/biological catalysts and antibodies
and make up many receptors and hormones. The main atoms in a
protein are carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and
sulphur (S).
