1. Which type of carbohydrates lead to the formation of glycolipids and glycoproteins?
a) Oligosaccharides
b) Monosaccharides
c) Glycogen
d) Glucose
Explanation: Oligosaccharides are formed when sugar molecules link to form small chains (oligo means few). These form covalent bonds with lipids and proteins generating glycolipids and glycoproteins.
2. Which of the following polysaccharide is not entirely composed of glucose subunits?
a) Lactose
b) Starch
c) Glycogen
d) Cellulose
Explanation: Lactose is a disaccharide molecule found in milk. Glycogen, starch and cellulose are all polysaccharides composed entirely of glucose subunits. They have same constitution but different chemical and physical properties.
3. Lipids cannot dissolve in _____________
a) organic solvents
b) chloroform
c) benzene
d) water
Explanation: Lipids are vital biomolecules that have a characteristic property of being able to dissolve in organic solvents such as benzene and chloroform and their inability to dissolve in water.
4. Which types of bonds are found in fats?
a) amide
b) glycosidic
c) ester
d) acidic
Explanation: Fatty acids consist of one glycerol moiety linked to three fatty acids via ester bonds; the composite molecule is called triacylglycerol or neutral fat.
5. How many carboxyl groups are present in fatty acids?
a) 1
b) 2
c) 3
d) 4
Explanation: Fatty acids are long chain hydrocarbons containing only one carboxyl group at the end of the molecule. Three fatty acid chains link up via ester bonds to a glycerol molecule to form triacylglycerol. The hydrocarbon chain of fatty acids is hydrophobic and the carboxyl group is hydrophilic.
6. Fatty acids that lack double bonds are call saturated.
a) true
b) false
Explanation: Fatty acids differ from each other by the length of hydrocarbon chain present and the nature of bonds between the atoms. Those with presence of double bonds are called unsaturated fatty acids and the other group is called saturate fatty acids
7. Which type of bonds present in vegetable fats account for their liquid state?
a) Single bonds
b) Double bonds
c) Amide bonds
d) Glycosidic bonds
Explanation: Double bonds are profusely present in the vegetable fats which account for their liquid state at room temperature. Due to this reason they are also known as polyunsaturated. Fats that are liquid at room temperature are called oils.
8. Margarine is formed using unsaturated vegetable fats by _________________
a) oxidation
b) catalysis
c) hydrogenation
d) leaching
Explanation: Solid shortenings such as margarine are formed by chemically reducing the double bonds present in polyunsaturated vegetables with hydrogen atoms. This hydrogenation process also converts some of the cis-double bonds to trans-double bonds which are straight rather than kinked; called partially hydrogenated or trans-fats.
9. Fats contain more chemical energy than carbohydrates.
a) true
b) false
Explanation: Fats contain more energy content than carbohydrates. A gram of fat contains twice the energy than a gram of carbohydrates. Carbohydrates serve as short-term, readily available energy whereas fat reserves store energy on long-term basis.
10. In most animals, fats are stored in special cells called _____________
a) telomeres
b) granulocytes
c) lymphoid cells
d) adipocytes
Explanation: In many animals, fats are stored in adipocytes cytoplasm of which contains one or a few large droplets of lipids. Adipocytes have the ability to change their shape to accommodate varying quantities of fats.