Describe an enzymes’ secondary structures and how they maintain their shape,
additionally describe and explain the tertiary and quaternary structure of the
enzyme (P3/M2)
Amylase is a digestive enzyme that acts on starch in food, breaking it down into smaller
carbohydrate molecules. The salivary glands in your mouth make salivary amylase, which
begins the digestive process by breaking down starch. When starchy food is eaten, a sweet
taste may be detected as maltose is produced by the breaking down of starch.
The image to the left shows the Amylase enzyme. It is
made mostly up of alpha-helices and some beta-pleated
sheets which is part of its secondary structure.
In the alpha-helix, the polypeptide chain is wound around
and is held together by hydrogen bands running parallel
with the long helical axis. There are many hydrogen bonds
causing it to be very stable.
Beta-pleated sheets are also formed and this causes the
polypeptide chain to zig-zag backwards and forwards
forming antiparallel strands which are also held together by
hydrogen bonds.
The secondary structure is very stable due to having so many hydrogen bonds and as such is
able to hold together its shape easily. It is due to backbone interactions and is largely
independent of the primary sequence, however the next type of structure, tertiary, is mainly
due to side chain interactions and as a result is dependent on amino acid sequence.
The tertiary structure is the compact globular structure and is especially important for
enzymes due to the creation of an active site in its tertiary structure.
It is held together by bonds between the R-groups of the amino acids in the protein, there are
weak hydrogen bonds between the hydroxyl and hydrogen groups of the amino acids, ionic
bonds which are stronger but damaged when pH changes, disulfide bonds which are between
sulfur molecules and are very strong. There are also hydrophobic interactions between
hydrophilic and hydrophobic R-groups.
The quaternary structure is when two or more polypeptide chains join together to form an
overall protein shape, amylase consists of three polypeptide chains and as such has a
quaternary structure.
Amylase is also regarded as a conjugate protein as it contains a calcium and chloride ion
within its structure.
The tertiary and quaternary structures produce the overall structure of the enzyme, the active
site is as such produced from the folding of it. The amylase structures produces a ‘spiked’
structure that is able to catalyse the reaction of breaking glycosidic bonds between adjacent
alpha-glucose molecules to hydrolyse sections of amylose into maltose.
additionally describe and explain the tertiary and quaternary structure of the
enzyme (P3/M2)
Amylase is a digestive enzyme that acts on starch in food, breaking it down into smaller
carbohydrate molecules. The salivary glands in your mouth make salivary amylase, which
begins the digestive process by breaking down starch. When starchy food is eaten, a sweet
taste may be detected as maltose is produced by the breaking down of starch.
The image to the left shows the Amylase enzyme. It is
made mostly up of alpha-helices and some beta-pleated
sheets which is part of its secondary structure.
In the alpha-helix, the polypeptide chain is wound around
and is held together by hydrogen bands running parallel
with the long helical axis. There are many hydrogen bonds
causing it to be very stable.
Beta-pleated sheets are also formed and this causes the
polypeptide chain to zig-zag backwards and forwards
forming antiparallel strands which are also held together by
hydrogen bonds.
The secondary structure is very stable due to having so many hydrogen bonds and as such is
able to hold together its shape easily. It is due to backbone interactions and is largely
independent of the primary sequence, however the next type of structure, tertiary, is mainly
due to side chain interactions and as a result is dependent on amino acid sequence.
The tertiary structure is the compact globular structure and is especially important for
enzymes due to the creation of an active site in its tertiary structure.
It is held together by bonds between the R-groups of the amino acids in the protein, there are
weak hydrogen bonds between the hydroxyl and hydrogen groups of the amino acids, ionic
bonds which are stronger but damaged when pH changes, disulfide bonds which are between
sulfur molecules and are very strong. There are also hydrophobic interactions between
hydrophilic and hydrophobic R-groups.
The quaternary structure is when two or more polypeptide chains join together to form an
overall protein shape, amylase consists of three polypeptide chains and as such has a
quaternary structure.
Amylase is also regarded as a conjugate protein as it contains a calcium and chloride ion
within its structure.
The tertiary and quaternary structures produce the overall structure of the enzyme, the active
site is as such produced from the folding of it. The amylase structures produces a ‘spiked’
structure that is able to catalyse the reaction of breaking glycosidic bonds between adjacent
alpha-glucose molecules to hydrolyse sections of amylose into maltose.
