CARBOHYDRATES 1 - MONOSACCHARIDES AND DISACCHARIDES

Question 1

What are monosaccharides?

Answer 1

Simple sugar monomer with one oxygen and two hydrogen atoms for each carbon.

Question 2

What is the general formula for monosaccharides?

Answer 2

(CH₂O)ₙ

Question 3

What is a monomer?

Answer 3

A small molecule that is a single unit of a larger molecule called a polymer.

Question 4

What is a polymer?

Answer 4

A long chain molecule made up of smaller, repeating monomer units joined together by chemical bonds.

Question 5

What is a macromolecule?

Answer 5

A very large molecule often formed by polymerisation.

Question 6

What is starch?

Answer 6

A long chain polymer formed of α-glucose monomers.

Question 7

What is sucrose?

Answer 7

A disaccharide formed by joining α-glucose and fructose by a glycosidic bond

Question 8

What is glucose?

Answer 8

A hexose sugar.

Question 9

What is a disaccharide?

Answer 9

A sugar made of two monosaccharide units joined by a glycosidic bond, formed in a condensation reaction.

Question 10

What is a polysaccharide?

Answer 10

A polymer made of long chains of monosaccharide units joined by glycosidic bonds.

Question 11

What is a triose sugar?

Answer 11

A sugar with 3 carbon atoms.

Question 12

What is a pentose sugar?

Answer 12

A sugar with 5 carbon atoms.

Question 13

What is ribose?

Answer 13

A pentose sugar that makes up part of the structure of RNA.

Question 14

What is deoxyribose?

Answer 14

A pentose sugar that makes up part of the structure of DNA.

Question 15

What is deoxyribonucleic acid (DNA)?

Answer 15

A nucleic acid that acts as genetic material in many organisms.

Question 16

What is ribonucleic acid (RNA)?

Answer 16

A nucleic acid that acts as the genetic material in some organisms and is involved in protein synthesis.

Question 17

What is a hexose sugar?

Answer 17

A sugar with 6 carbon atoms.

Question 18

What is an isomer?

Answer 18

Molecules that have the same chemical formula, but different molecular structures.

Question 19

What is a condensation reaction?

Answer 19

A reaction in which a molecule of water is removed from the reacting molecules as a bond is formed between them

Question 20

What is a glycosidic bond?

Answer 20

A covalent bond formed between two monosaccharides in a condensation reaction.

Question 21

What are reducing sugars?

Answer 21

Sugars that react with blue Benedict’s solution and reduce the copper(II) ions to copper(I) ions giving an orange/red precipitate.

Question 22

What are non-reducing sugars?

Answer 22

Sugars that don’t react with Benedict’s solution.

Question 23

What is lactose made of?

Answer 23

α-glucose + β-galactose

Question 24

What is maltose made of?

Answer 24

α-glucose + α-glucose

Question 25

What is sucrose source?

Answer 25

In plants.

Question 26

What lactose source?

Answer 26

Milk sugar - main carbohydrate in milk.

Question 27

What is maltose source?

Answer 27

Malt sugar - found in germinating seed (barley)

Question 28

What does molecule formula show you?

Answer 28

How many atoms there are in the molecule.

Question 29

If carbon 1 on one monosaccharide joins to carbon 4 on another monosaccharide, we call it a…

Answer 29

1,4-glycosidic bond.

Question 30

Each carbon atom can make how many bonds?

Answer 30

4.

Question 31

How do you test for sugars?

Answer 31

Benedict’s test

Question 32

What is the colour change in Benedict’s solution in reducing sugars?

Answer 32

Blue to orange.

Question 33

How do you get a positive Benedict’s test from a non-reducing sugar?

Answer 33

-Add a few drops of hydrochloric acid to hydrolyse the glycosidic bonds. Allow it to cool, neutralise the solution with sodium hydrogen carbonate. This produces the monosaccharide units of the sugar, which will now give a positive test.