Carbohydrates

Question 1

What is a monomer?

Answer 1

Smaller biological units from which larger molecules are made.

Question 2

What is a polymer?

Answer 2

A large number of similar monomers joined to make a larger molecule.

Question 3

How is a polymer formed?

Answer 3

The joining of similar monomers via a condensation reaction.

Question 4

What is a condensation reaction?

Answer 4

A condensation reaction causes the formation of a chemical bond, joining two molecules together. A water molecule is eliminated.

Question 5

How is a monomer formed?

Answer 5

The breaking of bonds between units in a polymer via hydrolysis.

Question 6

What is a hydrolysis reaction?

Answer 6

The breaking of a chemical bond between two molecules with the use of a water molecule.

Question 7

Give some examples of monomers.

Answer 7

Monosaccharides.
Amino acid.
Nucleotide.

Question 8

Give some examples of polymers.

Answer 8

Polysaccharides.
Polypeptide.
Polynucleotide.

Question 9

Is a disaccharide a polymer or a monomer?

Answer 9

Neither, it is a dimer.

Question 10

What elements form carbohydrates?

Answer 10

Carbon (carbo), hydrogen and oxygen (hydrate).

Question 11

What are the three groups of carbohydrates?

Answer 11

Monosaccharides, disaccharides, polysaccharides.

Question 12

What are some similarities between monosaccharides and disaccharides?

Answer 12

Small.
Water soluble.
Easy to transport.
Sweet.

Question 13

What are monosaccharides mainly used for?

Answer 13

Used in respiration to provide energy and used in growth during the formation of larger carbohydrates.

Question 14

Name three monosaccharides.

Answer 14

Glucose, fructose and galactose.

Question 15

What type of sugars are monosaccharides?

Answer 15

Reducing sugars.

Question 16

What is an isomer and can you give some examples?

Answer 16

An isomer is a molecule with the same formula but different structure to another molecule.

Question 17

Glucose has two _______.

Answer 17

Isomers. Alpha and beta.

Question 18

What is the difference between alpha and beta glucose?

Answer 18

The 2 hydroxyl groups in alpha glucose are on the same side of the molecule, both below the ring.
In beta glucose they are on opposite sides of the molecule, one below and one above the ring.

Question 19

Which carboyhdrates are reducing sugars?

Answer 19

All monosaccharides and disaccharides apart from sucrose.

Question 20

What are each glucoses used for in animals?

Answer 20

Alpha glucose is absorbed and used for respiration to provide energy.
Beta linked polymers can not be broken down in an animals digestive system so beta glucose is just egested.

Question 21

What is alpha glucose used for in plants?

Answer 21

Alpha glucose is used for respiration to provide energy.

Question 22

What is beta glucose used for in plants?

Answer 22

Large chains of beta glucose for cellulose which is tough and provides structural stength to the plant.

Question 23

What is a disaccharide?

Answer 23

A disaccharide is formed when two monosaccharides are joined together by a glycosidic bond via a condensation reaction.

Question 24

What is starch made of?

Answer 24

A mixture of two polysaccharides called amylose and amylopectin.

Question 25

What are amylopectin and amylose made up of?

Answer 25

Alpha-glucose molecules.

Question 26

What are the structural differences between amylose and amylopectin?

Answer 26

Amylose is an unbranched chain joined by 1-4 glycosidic bonds forming a helical structure. Amylopectin is branched joined by 1-4 and 1-6 glycosidic bonds.

Question 27

How does amylose's structure help its function?

Answer 27

The helical non-branched structure makes is a very compact molecule storing a lot of energy.

Question 28

How does amylopectin's structure help its function?

Answer 28

The side branches mean there are more bonds per area for enzymes to break down thus increasing the rate of hydrolysis of the molecule.

Question 29

What are some properties of starch?

Answer 29

-Insoluble. -Compact molecule. -To big as its polymer to diffuse through a cells semi-permeable membrane.

Question 30

How does starches properties make it good for its function?

Answer 30

-Insoluble so doesn't affect water potential of cell (osmotically inactive) -Compact molecule so lots of energy stored in a small space. -Large molecule so won't diffuse out of cell.

Question 31

What are some properties of glycogen?

Answer 31

-Insoluble. -Highly branched molecule. -Compact molecule. -Too big, as it is a polymer, to diffuse through a cell's semi-permeable membrane.

Question 32

What is the structure of cellulose?

Answer 32

-Unbranched chain of beta-glucose joined by 1-4 glycosidic bonds. -Every other beta-glucose molecule is inverted.

Question 33

What is a microfibril and its structure?

Answer 33

Strong threads made of long cellulose chains running parallel to each other joined together by hydrogen bonds between the hydroxyl group of one beta molecule and the hydroxyl group of an adjacent beta glucose molecule. Found in plant cell walls.

Question 34

What is the function of microfibrils?

Answer 34

To provide strength and rigidity to plant cell walls. This helps prevent the cell from bursting under osmotic pressure.

Question 35

Are polysaccharides soluble in water?

Answer 35

No, they are non polar molecules and are too large.