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ANSWERS TO SAQs
Subject: Chemistry / Medicine
Unit: Applied Biochemistry
Topic: Applied Biochemistry
Level: 3
SAQ 1:
1. Explain the difference between a disaccharide and a
polysaccharide.
2. What biomolecule is required as a reactant in a Hydrolysis reaction,
and forms s by-product in a condensation reaction?
Answer:
1. A disaccharide consists of two monosaccharides bonded together (e.g.
two glucose monomers are joined to form the disaccharide maltose). A
polysaccharide is created when many monosaccharides are joined
together, creating complex structures (e.g. many glucose monomers are
bonded together to form glycogen).
2. Water (H2O)
SAQ 2:
1. Describe the differences in the structure of a Triglyceride and a
phospholipid.
Answer:
1. A triglyceride is composed of a glycerol molecule with three attached
fatty acid chains attached (via ester bonds). A phospholipid consists of a
glycerol molecule with only two fatty acid chains (tails) attached, the third
fatty acid chain is replaced by a phosphate group.
© DistanceLearningCentre.com, 2022 1
, Subject: Chemistry / Medicine
Unit: Applied Biochemistry
Topic: Applied Biochemistry
Level: 3
ANSWERS TO SAQs
SAQ 3:
1. Describe the structure of an amino acid.
2. Proteins have a structural hierarchy, list the four structures that
make up this hierarchy.
Answer:
1. An amino acid possesses an amino group (NH3) and a Carboxylic acid
(COOH) attached either side to a central carbon. Also bonded to this
central carbon is a hydrogen atom and a function (R) group.
2. Primary Structure;
Secondary Structure;
Tertiary structure;
Quaternary structure.
SAQ 4:
1. What do enzymes do?
Answer:
1. Enzymes are biological catalysts. They are a group of proteins, and their
role is to speed up reactions within the body. They achieve this by
lowering activation energy
SAQ 5:
1. What is the lock and key model?
2. How does the induced fit theory differ from the lock and key
theory?
Answer:
1. The lock and key model was put forward by Emil Fischer in 1894 and the
idea is that the lock is the enzyme itself and the key to get into to it is the
substrate. So only the correct substrate (the key) will fit into the keyhole
(the active site) of the enzyme (the lock).
2. The induced fit model on the other hand works on the principle that an
enzymes active site is similar in shape to (but not identical to) its
substrate. However, the binding of the substrate to this region initiates a
conformational change to the active site, thus creating a stable enzyme-
substrate complex.
© DistanceLearningCentre.com, 2022 2
ANSWERS TO SAQs
Subject: Chemistry / Medicine
Unit: Applied Biochemistry
Topic: Applied Biochemistry
Level: 3
SAQ 1:
1. Explain the difference between a disaccharide and a
polysaccharide.
2. What biomolecule is required as a reactant in a Hydrolysis reaction,
and forms s by-product in a condensation reaction?
Answer:
1. A disaccharide consists of two monosaccharides bonded together (e.g.
two glucose monomers are joined to form the disaccharide maltose). A
polysaccharide is created when many monosaccharides are joined
together, creating complex structures (e.g. many glucose monomers are
bonded together to form glycogen).
2. Water (H2O)
SAQ 2:
1. Describe the differences in the structure of a Triglyceride and a
phospholipid.
Answer:
1. A triglyceride is composed of a glycerol molecule with three attached
fatty acid chains attached (via ester bonds). A phospholipid consists of a
glycerol molecule with only two fatty acid chains (tails) attached, the third
fatty acid chain is replaced by a phosphate group.
© DistanceLearningCentre.com, 2022 1
, Subject: Chemistry / Medicine
Unit: Applied Biochemistry
Topic: Applied Biochemistry
Level: 3
ANSWERS TO SAQs
SAQ 3:
1. Describe the structure of an amino acid.
2. Proteins have a structural hierarchy, list the four structures that
make up this hierarchy.
Answer:
1. An amino acid possesses an amino group (NH3) and a Carboxylic acid
(COOH) attached either side to a central carbon. Also bonded to this
central carbon is a hydrogen atom and a function (R) group.
2. Primary Structure;
Secondary Structure;
Tertiary structure;
Quaternary structure.
SAQ 4:
1. What do enzymes do?
Answer:
1. Enzymes are biological catalysts. They are a group of proteins, and their
role is to speed up reactions within the body. They achieve this by
lowering activation energy
SAQ 5:
1. What is the lock and key model?
2. How does the induced fit theory differ from the lock and key
theory?
Answer:
1. The lock and key model was put forward by Emil Fischer in 1894 and the
idea is that the lock is the enzyme itself and the key to get into to it is the
substrate. So only the correct substrate (the key) will fit into the keyhole
(the active site) of the enzyme (the lock).
2. The induced fit model on the other hand works on the principle that an
enzymes active site is similar in shape to (but not identical to) its
substrate. However, the binding of the substrate to this region initiates a
conformational change to the active site, thus creating a stable enzyme-
substrate complex.
© DistanceLearningCentre.com, 2022 2
