Water provides a constant external environment for many aquatic organisms. The specific property of water which allows for this is

• high heat capacity

• high heat of vaporization

• high surface tension

• high heat of fusion

The 3-unit molecular structure shown is found in which of the following polymers?

• glycogen

• cellulose

• starch

• collagen

How many fatty acid chains are normally present in a phospholipid molecule?

• 1

• 2

• 3

• 4

Which of the following functional groups must combine to form a peptide bond?

• 1 and 2

• 3 and 4

• 2 and 4

• 2 and 3

Which of the following types of bonds is responsible for stabilizing the secondary structure of a protein?

• disulphide

• hydrophobic

• ionic

• hydrogen

Which of the following molecules shows the characteristics listed?

I. The triple helices are linked by covalent cross links.

II. They are polypeptides in the form of three helices.

III. Every third amino acid in each helix is glycine.

• collagen

• glycogen

• haemoglobin

• glycoprotein

One of the roles of water in living organisms is that it acts as a transport medium in blood. Which of the following properties of water accounts for this role?

• high specific heat capacity

• strong cohesive forces between molecules

• high heat of vaporisation

• solvent for polar molecules and ions

Indicate the form of glucose and where it is found.

• alpha - cellulose

• alpha - starch

• beta - cellulose

• beta - starch

The diagram shows a growing polysaccharide chain.

The name of the bond labelled X is

• glycosidic

• peptide

• hydrogen

• diester

The diagram shows the structure of a triglyceride. What is the bond labelled X?

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