1.1 Carbohydrates

Question 1

What is alpha glucose?

Answer 1

An isomer of glucose where the hydroxy (OH) group on the carbon-1 is above the plane of the ring

Question 2

What is beta glucose?

Answer 2

An isomer of glucose where the hydroxy (OH) group on the carbon-1 is below the plane of the ring

Question 3

What is cellulose and what does it do?

Answer 3

It is a structural polysaccharide composed of beta glucose monomers joined by (1,4) glycosidic bonds that composes the cell wall of plants

Question 4

What is a condensation reaction?

Answer 4

A type of reaction between two molecules which forms a bond and releases water

Question 5

What is a disaccharide?

Answer 5

A molecule formed by the condensation of two monosaccharides

Question 6

What is glycogen and what is it used for?

Answer 6

It is a highly branched polysaccharide composed of alpha glucose monomers that is used as the main storage of energy in humans and animals

Question 7

What is glycosidic linkage?

Answer 7

A C-O-C covalent bond formed between two sugars during a condensation reaction

Question 8

What is hydrolysis?

Answer 8

A type of reaction which breaks a chemical bond using a molecule of water

Question 9

What is lactose?

Answer 9

A simple disaccharide composed of alpha glucose and galactose monomers joined by a glycosidic bond

Question 10

What is maltose?

Answer 10

A simple disaccharide composed of two alpha glucose molecules joined by a glycosidic bond

Question 11

What is a monosaccharide?

Answer 11

The individual sugar monomers from which larger carbohydrates are made

Question 12

What is a polysaccharide?

Answer 12

Polymers formed by the condensation of many monosaccharides

Question 13

What is ribose and where is it found?

Answer 13

It is a 5 carbon sugar which is found in the structure of molecules like RNA

Question 14

What is starch and what is it used for?

Answer 14

It is a polysaccharide composed of amylose and amylopectin that is used as the main storage of energy in plants

Question 15

What is sucrose?

Answer 15

A simple disaccharide composed of alpha glucose and fructose monomers joined by a glycosidic bond

Question 16

What is a carbohydrate?

Answer 16

A type of molecule that is composed only of carbon, hydrogen and oxygen

Question 17

What are the 6 monosaccharides?

Answer 17

Alpha glucose, beta glucose, ribose, deoxyribose, fructuse and galactose

Question 18

What are the 3 disaccharides?

Answer 18

Maltose, sucrose and lactose

Question 19

What are the 5 polysaccharides?

Answer 19

Glycogen, starch, cellulose, amylose and amylopectin

Question 20

What is the structure of glycogen and how does this relate to it’s function?

Answer 20

It is a highly branched polysaccharide composed of many alpha glucose monomers joined together by (1,4) and (1,6) glycosidic bonds. It is also a very large but compact molecule, making it optimal for energy storage, and due to it’s high number of side branches it can be hydrolysed very quickly for the rapid energy release needed in humans and animals.

Question 21

What is the structure of starch?

Answer 21

A mixture of the two polysaccharides amylose and amylopectin.

Question 22

What is the structure of cellulose and how does this relate to it’s function?

Answer 22

It is a structural polysaccharide that is a long, unbranched chain of beta glucose monomers joined by (1,4) glycosidic bonds. The microfibres and microfibrils in plant cell walls are strong threads that are composed of these chains, as strong hydrogen bonds form between them providing the structural support needed in the cells

Question 23

What is the structure of amylose and how does this relate to it’s function in starch?

Answer 23

It is a polysaccharide that is an unbranched chain of alpha glucose monomers joined by (1,4) glycosidic bonds. Due to it’s unbranched structure, it can coil, and is therefore a very compact and efficient storage of energy

Question 24

What is the structure of amylopectin and how does this relate to it’s function in starch?

Answer 24

It is a highly branched polysaccharide composed of alpha glucose monomers joined by (1,4) and (1,6) glycosidic bonds. Due to it’s many side branches, it can be rapidly digested by enzymes and so releases energy very quickly