Biological Molecules (Water)

The movement of water through the vascular tissue of plants relies on which property of water?

• changes in density with temperature
• good solvent for ions and polar molecules
• high specific heat capacity
• strong cohesive forces between molecules

Which features of water is least likely to affect the life of an animal in a tropical rain forest?

• adhesion with other molecules

• cohesion between water molecules

• low viscosity

• maximum density of water at 4oC

which bond is responsible for the important benefits that water contributes to life?

• covalent bond
• disulphide bonds
• hydrogen bonds
• Van der Waals bonds

which properties of water are a result of only cohesion? (1) the water has a high surface tension (2) water moves up the xylem vessels (3) water is an excellent solvent

• 1,2 and 3
• 1 and 2 only
• 1 only
• 3 only

Which of the following reactions requires water? (1) condensation (2) hydrolysis (3) polymerisation

• 1 and 2 only

• 1,2 and 3

• 2 and 3 only

• 2 only

Which of the following is not a role played by water in plant cells (1)It serves as raw material for photosynthesis (2) it serves as raw material for protein synthesis (3) it is necessary for the transport of materials down the phloem (4) it is necessary for the transport of materials down the xylem

• 2 and 4 only

• 1,2,3 and 4

• 1 and 3 only

• 1, 3 and 4 only

Which of the following explains why glucose readily dissolves in water whereas starch does not

• glucose readily forms dipole dipole interaction with water molecules
• glucose readily forms hydrogen bonds with water molecules
• glucose readily reacts with water to produce ATP
• glucose readily reacts with each other to form starch

What percentage of the average human bone is constituted by water?

• 0.6
• 0.8
• 0.2
• 0.005

Water readily forms ………………..with ions and ……………………..with polar molecules

• hydrogen bonds, dipole interactions
• dipole interactions, hydrogen bonds
• covalent interactions, hydrogen bonds
• hydrogen bonds, covalent interactions

When fructose dissolves in water, the hydrogen bonds formed are between ………………..

• hydrogen of fructose and hydrogen of water
• hydrogen of fructose and oxygen of water
• oxygen of fructose and oxygen of water
• carbon of fructose and hydrogen of water