2. Biological Molecules

Question 1

What is a Monomer?

Answer 1

A relatively simple molecule used as a basic building block for the synthesis of a polymer.

Examples include monosaccharides, amino acids, and nucleotides.

Question 2

How are Monomers related to Polymers?

Answer 2

Many monomers are joined together by covalent bonds to make a polymer, usually by condensation reactions.

Question 3

What is a polymer?

Answer 3

A giant molecule made from similar subunits joined together in a chain.

Question 4

What are examples of polymers?

Answer 4

Polysaccharides, proteins, and nucleic acids (polynucleotides).

Question 5

What is a macromolecule?

Answer 5

A large molecule such as a polysaccharide, protein, or nucleic acid.

Question 6

What are examples of macromolecules?

Answer 6

Polysaccharides, proteins (polypeptides), nucleic acids (polynucleotides).

Question 8

What is maltose composed of?

Answer 8

Maltose is composed of glucose + glucose.

Question 9

What is sucrose composed of?

Answer 9

Sucrose is composed of glucose + fructose.

Question 10

What is lactose composed of?

Answer 10

Lactose is composed of glucose + galactose.

Question 11

How are disaccharides formed?

Answer 11

Disaccharides are formed by a condensation reaction.

Question 12

What type of bond is formed in disaccharides?

Answer 12

A glycosidic bond is formed.

Question 13

How can a glycosidic bond be broken?

Answer 13

A glycosidic bond can be broken by a hydrolysis reaction.

Question 15

What is the main source of energy for cells?

Answer 15

Glucose is the main source of energy for cells and must be stored.

Question 16

Why is glucose not stored directly in cells?

Answer 16

Glucose affects osmotic properties of cells and is very reactive, interfering with normal cell chemistry.

Question 17

What is a storage polysaccharide?

Answer 17

A storage polysaccharide is a convenient, compact, inert (unreactive), and insoluble molecule.

Question 18

What is the storage polysaccharide in plants?

Answer 18

Starch

Question 19

What is the storage polysaccharide in animals?

Answer 19

Glycogen

Question 20

How is glucose made available when needed?

Answer 20

Glucose is quickly made available again by enzyme-controlled hydrolysis reactions.

Question 21

What is cellulose?

Answer 21

Cellulose is a polysaccharide made from beta-glucose subunits; used as a strengthening material in plant cell walls.

Question 23

What are oligosaccharides?

Answer 23

Oligosaccharides are carbohydrates formed from a small number of monosaccharides.

Question 24

What is starch?

Answer 24

Starch is a mixture of two substances - amylose and amylopectin.

Question 25

Where are starch grains formed?

Answer 25

Starch grains are formed in chloroplasts and storage organs.

Question 26

What is amylose?

Answer 26

Amylose is formed by a condensation reaction between a-glucose molecules.

Question 27

What is the structure of amylose?

Answer 27

Amylose consists of a long, unbranching chain of several thousand glucose molecules.

Question 28

How are glucose molecules linked in amylose?

Answer 28

Glucose molecules in amylose are linked by 1,4 glycosidic bonds.

Question 29

What is the shape of amylose chains?

Answer 29

Amylose chains are curved and coil up into helical structures.

Question 30

What is the final structure of amylose?

Answer 30

The final molecule of amylose is compact.

Question 32

What is amylopectin formed by?

Answer 32

Amylopectin is formed by a condensation reaction between a-glucose molecules.

Question 33

How does the length of amylopectin compare to other polysaccharides?

Answer 33

Amylopectin is comparatively shorter.

Question 34

What types of glycosidic bonds link amylopectin?

Answer 34

Amylopectin is linked by 1,4 and 1,6 glycosidic bonds.

Question 35

How does amylopectin structure branch?

Answer 35

Amylopectin branches out to the sides of the chain.

Question 36

What is the final structure of amylopectin like?

Answer 36

The final molecule of amylopectin is compact.