1.1: Carbohydrates

Question 1

What is the monomer of a sugar called?

Answer 1

A saccharide.

Question 2

What is a carbohydrate made up of?

Answer 2

Carbon, hydrogen and oxygen.

Question 3

What are carbohydrates joined by?

Answer 3

Glycosidic bonds.

Question 4

What are the four polysaccharides?

Answer 4

Starch, glyocgen, cellulose and chitin.

Question 5

What is lactose made of?

Answer 5

Glucose and galactose.

Question 6

What is the structure of an alpha glucose?

Answer 6

H is above the OH.

Question 7

What is the structure of a beta glucose?

Answer 7

Oh is above the H.

Question 8

Why is starch useful?

Answer 8

Doesn’t interfere with osmosis because it is insoluable. Osmotically stable.

Question 9

What is starch made of?

Answer 9

Amylose and Amylopectin.

Question 10

What forms maltose?

Answer 10

Two alpha glucose.

Question 11

What forms sucrose?

Answer 11

Glucose and fructose.

Question 12

What are the units that make up an organic chain called?

Answer 12

A monomer.

Question 13

How do monomers join to form longer chains?

Answer 13

The carbon atoms of the monomers join to form longer chains.

Question 14

What are the longer chains of repeating monomer units called?

Answer 14

Polymers.

Question 15

Give examples of a polymer.

Answer 15

Carbohydrates and Proteins are often polymers.

Question 16

How many elements are polymers made of?

Answer 16

Carbon, Hydrogen, Oxygen and Nitrogen.

Question 17

A single monomer of a carbohydrate is?

Answer 17

Monosaccharide.

Question 18

Monosaccharides can be combined to form?

Answer 18

Polysaccharides.

Question 19

Give an example of a monosaccharide?

Answer 19

Glucose.

Question 20

Monosaccharides are joined together by?

Answer 20

Condensation reactions.

Question 21

What are carbon sugars?

Answer 21

Deoxyribose and ribose.

Question 22

What are the polysaccharides?

Answer 22

Starch, Glycogen, Cellulose and Chitin.

Question 23

What is starch?

Answer 23

The main storage of glucose for plants.

Question 24

Where is starch found?

Answer 24

In large concentrations within potato tubers/seeds.

Question 25

What is starch made up of?

Answer 25

Alpha glucose molecules bonded together in two different ways, forming amylose and amylopectin.

Question 26

What does amylose and amylopectin form together?

Answer 26

Starch.

Question 27

What structures do amylose and amylopectin have?

Answer 27

Amylose = forms coiled molecules, amylopectin = a branched molecule

Question 28

What is the form of amylopectin?

Answer 28

The bonds between glucose molecules within a branch are α-1,4 glycosidic bonds but at branching points, the bonds are α-1,6 glycosidic bonds.

Question 29

What is the description for amylose?

Answer 29

A linear, unbranched molecule with α-1,4 glycosidic bonds forming between the 1st carbon (C1) on one glucose monomer and the 4th carbon atom (C4) on the adjacent one. This is repeated, forming a chain which coils into a helix.

Question 30

What is the description for amylopectin?

Answer 30

Has chains of glucose monomers joined with α-1,4 glyosidic bonds. They are cross-linked with α-1,6 glyosidic bonds and fit inside the amylose.

Question 31

The structures of amylopectin and amylose make starch..?

Answer 31

It makes starch a compact molecule that is less soluble in water.

Question 32

A property of starch is?

Answer 32

It s osmotically stable.

Question 33

What is glycogen?

Answer 33

The main storage product in animals.

Question 34

What is the structure of glycogen?

Answer 34

Glycogen is similar to amylopectin but is even more branched due to glycosidic bonds forming between OH groups on C1 and C4 but also C1 and C6.

Question 35

Glycogen can form ___ in cells?

Answer 35

Granules, and act as a energy store.

Question 36

Why are the branches in glycogen useful?

Answer 36

The branches in amylopectin and glycogen make them better for the release of glucose. This is because there are more ‘ends’ where glycosidic bonds can be hydrolysed and glucose released, which can be used in respiration to produce ATP.

Question 37

Cellulose is made up of?

Answer 37

A polymer of b-glucose.

Question 38

What is the structure of cellulose?

Answer 38

B-14 glycosidic linkages result in the −CHX2​OH groups being on opposite sides of the chain of adjacent glucose molecules.

Question 39

In cellulose, adjacent molecules are..?

Answer 39

Adjacent glucose molecules are rotated 180° relative to each other.

Question 40

What does the rotation do for cellulose?

Answer 40

This means that OH groups are aligned and a water molecule can be removed to form a glycosidic bond. Therefore, hydrogen bonds do not form between glucose molecules within the same chain.

Question 41

Hydrogen bonds in cellulose form..?

Answer 41

Cross-linkages which holds chains together. This makes cellulose form microfibrils.

Question 42

What are the properties of Cellulose?

Answer 42

Completely insoluble.

Question 43

What is Chitin made of?

Answer 43

Long chains of b-glucose molecules linked by C1 - C4 glycosidic bonds. Each monomer has a group derived from amino acids added, called an acetylamine group.

Question 44

What is the rotation of Chitin?

Answer 44

Alternate glucose molecules are rotated by 180.

Question 45

What are the properties of Chitin?

Answer 45

Strong, waterproof and lightweight.

Question 46

Define Chitin.

Answer 46

a nitrogen-containing polysaccharide, related chemically to cellulose, that forms a semi-transparent horny substance and is the main structure of the exoskeleton, or outer covering, of insects, crustaceans, and arachnids.

Question 47

What is a test for a reducing sugar?

Answer 47

Benedicts reagent. Turns from blue to orange.

Question 48

What is the test for starch?

Answer 48

Iodine. Yellow to black.