GRADE: /52
MOL BIO I EXAM
1- Explain, with reference to its properties, the significance of water as a coolant, a means
of transport and as a habitat. (8 points)
Water is a good coolant as it has a high specific heat capacity which basically means that it
takes a lot of energy to raise the temperature of water, as hydrogen bonds have to be
broken. Because it has a high specific heat capacity, it is a good habitat as it has a large
range of temperature(from 0C to 100C) where it is on its liquid state, making it a stable
environment for organisms. It is a good means of transport especially in the leaves of
plants due to the fact that it has adhesive and cohesive properties, which means that the
water molecule is able to bond with other water molecules(adhesion)and with other polar
molecules(cohesion) as well.
2-Outline the role of condensation and hydrolysis in the relationship between amino acids
and dipeptides .(4 points)
Dipeptides are formed by the bonding of two amino acids. These amino acids bond to each
other in a process called condensation, which, in this case, happens in the ribosomes and is
known as translation. During this process, ATP is required and H2O is released. The amine
group of one amino acids joins with the carboxyl group of the other in order to form a
dipeptide and the bond that keeps these two amino acids together is called a peptide
bond. Hydrolysis is the opposite process, in which large molecules are broken down into
smaller ones, in this process a dipeptide will become two amino acids. During this process
water is required and energy is released.
3- What property of water makes it suitable as a coolant? (1point)
A. It takes a lot of energy to increase the temperature of water.
B. It takes a lot of energy to break the hydrogen bonds between the oxygen atoms.
C. Water molecules are cohesive and stick to the skin.
D. Water is a good solvent so it can transport heat from the body.
, 4- Which molecule is a polysaccharide? (1point)
A. Cellulose
B. Fructose
C. Maltose
D. Sucrose
5- What are the most frequent occurring elements in living organisms?
A. calcium, phosphorus, iron and sodium
B. calcium, sodium, nitrogen and phosphorus
C. carbon, phosphorus, oxygen and nitrogen
D. nitrogen, carbon, oxygen and hydrogen
6- Which molecules are monosaccharides? (1 point)
A. starch, glycogen, cellulose
B. sucrose, maltose, lactose
C. fructose, glucose, galactose
D. glucose, lactose, cellulose
7- The diagrams show three representations of the structure of the same chemical
substance. (1 point)
MOL BIO I EXAM
1- Explain, with reference to its properties, the significance of water as a coolant, a means
of transport and as a habitat. (8 points)
Water is a good coolant as it has a high specific heat capacity which basically means that it
takes a lot of energy to raise the temperature of water, as hydrogen bonds have to be
broken. Because it has a high specific heat capacity, it is a good habitat as it has a large
range of temperature(from 0C to 100C) where it is on its liquid state, making it a stable
environment for organisms. It is a good means of transport especially in the leaves of
plants due to the fact that it has adhesive and cohesive properties, which means that the
water molecule is able to bond with other water molecules(adhesion)and with other polar
molecules(cohesion) as well.
2-Outline the role of condensation and hydrolysis in the relationship between amino acids
and dipeptides .(4 points)
Dipeptides are formed by the bonding of two amino acids. These amino acids bond to each
other in a process called condensation, which, in this case, happens in the ribosomes and is
known as translation. During this process, ATP is required and H2O is released. The amine
group of one amino acids joins with the carboxyl group of the other in order to form a
dipeptide and the bond that keeps these two amino acids together is called a peptide
bond. Hydrolysis is the opposite process, in which large molecules are broken down into
smaller ones, in this process a dipeptide will become two amino acids. During this process
water is required and energy is released.
3- What property of water makes it suitable as a coolant? (1point)
A. It takes a lot of energy to increase the temperature of water.
B. It takes a lot of energy to break the hydrogen bonds between the oxygen atoms.
C. Water molecules are cohesive and stick to the skin.
D. Water is a good solvent so it can transport heat from the body.
, 4- Which molecule is a polysaccharide? (1point)
A. Cellulose
B. Fructose
C. Maltose
D. Sucrose
5- What are the most frequent occurring elements in living organisms?
A. calcium, phosphorus, iron and sodium
B. calcium, sodium, nitrogen and phosphorus
C. carbon, phosphorus, oxygen and nitrogen
D. nitrogen, carbon, oxygen and hydrogen
6- Which molecules are monosaccharides? (1 point)
A. starch, glycogen, cellulose
B. sucrose, maltose, lactose
C. fructose, glucose, galactose
D. glucose, lactose, cellulose
7- The diagrams show three representations of the structure of the same chemical
substance. (1 point)
