Carbohydrates

Question 1

Roles of carbohydrates

Answer 1

Provide energy.
Energy Storage.
Provide Strength.

Question 2

What do carbs contain (Structure)

Answer 2

Carbon, Hydrogen, Oxygen

Question 3

What are the three groups of carbs

Answer 3

Monosaccharides, Disaccharides, Polysaccharides

Question 4

What is a monosaccharide

Answer 4

Simple sugars, General formula (CH20)n, where n can be 3-7

Question 5

What are Disaccharides

Answer 5

‘Double sugars’ formed from 2 monosaccharides

Question 6

What are polysaccharides

Answer 6

Large molecules formed from many monosaccharides

Question 7

Examples of monosaccharides

Answer 7

Glucose (Energy source for cell),
Fructose (Found in fruit),
Galactose (Sugar in milk)

Question 8

Whats the most important monosaccharide and why

Answer 8

Glucose, Main form in which carbohydrates are transported around the body of animals, major energy source for most cells, highly soluble

Question 9

What are the three structures of glucose

Answer 9

Straight chain, ring, simplified ring

Question 10

How are the Carbons numbered in a glucose ring

Answer 10

Taking the position of the individual O atom (in a ring), and going in a clockwise direction, each carbon atom is numbered from 1 to 6.

Question 11

What are the different forms glucose exist in called

Answer 11

Structural Isomers

Question 12

What are two common isomers called

Answer 12

Alpha and Beta glucose

Question 13

Whats the only difference between the two glucose isomers

Answer 13

The position of the -OH group attached to C1

Question 14

Where is the -OH in an alpha glucose

Answer 14

Below C1

Question 15

Where is the -OH in a Beta glucose

Answer 15

Above C1

Question 16

Solubility of fructose

Answer 16

Very soluble - main sugar in fruits and nectar, sweeter than glucose

Question 17

Solubility of Galactose

Answer 17

Not as soluble as glucose - Has important role in the production of glycolipids and glycoproteins

Question 18

Examples of dissaccharides

Answer 18

Maltose (Energy source for cell).
Sucrose (Found in fruit).
Lactose (Sugar in Milk).

Question 19

How are dissaccharides formed?

Answer 19

When 2 monosaccharide molecules join together with a glycosidic bond

Question 20

How is a glycosidic bond formed

Answer 20

Forms between a hydroxyl (OH) group on one monosaccharide molecule and a Hydroxyl group on another monosaccharide

Question 21

Where is the bond in Maltose, Sucrose and lactose

Answer 21

Between C1 on one monosaccharide and C4 on the other

Question 22

What type of reaction is a glycosidic bond and why

Answer 22

Condensation Reaction - The bond creates water

Question 23

How can you break a glycosidic bond

Answer 23

Adding water in a hydrolysis reaction

Question 24

How is maltose formed

Answer 24

two glucose molecules joined by an alpha 1-4 glycosidic bond

Question 25

How is sucrose formed

Answer 25

From a glucose and a fructose joined by an alpha 1-4 glycosidic bond

Question 26

How is lactose formed

Answer 26

From a galactose and glucose joined by a beta 1-4 glycosidic bond

Question 27

How are polysaccharides formed

Answer 27

Condensation reactions

Question 28

What are polysacchardies used for mainly

Answer 28

Energy store, and as structural components of cells

Question 29

What are the major polysaccharides

Answer 29

Starch and cellulose in plants, glycogen in animals

Question 30

What are the two structural units of starch

Answer 30

amylose (Straight chains) Amylopectin (Branched chains)

Question 31

Structure of amylose

Answer 31

Contains glucose molecules joined mainly with alpha 1-4 glycosidic bonds which result in unbranched chains forming a compact helical structure

Question 32

Structure of amylopectin

Answer 32

contains glucose molecules joined by alpha 1-4 glycosidic bonds, but it also contains many more alpha 1-6 glycosidic bonds. 1-6 bond causes branches

Question 33

How much amylopectin in starch

Answer 33

70-80%

Question 34

Where is starch stored

Answer 34

Stored as intracellular starch grains in plastids

Question 35

How is starch produced

Answer 35

From glucose made during synthesis. It is broken down during respiration to provide energy and is also a source of carbon for producing other molecules

Question 36

What is glycogen

Answer 36

Animals store carbohydrates as glycogen - has similar structure to part of starch molecule

Question 37

How is glycogen stored

Answer 37

As small granules particularly in muscles and liver

Question 38

Properties of glycogen

Answer 38

Less dense, more soluble than starch, broken down more rapidly.

Question 39

Glycogen structure

Answer 39

1-4 glycosidic bonds and also 1-6

Question 40

What is cellulose

Answer 40

It is another polysaccharide, main part of plant cell wall. Most abundant organic polymer

Question 41

Properties of cellulose

Answer 41

Unlike starch, very strong, prevents cells from bursting when taking in excess water

Question 42

Structure of cellulose

Answer 42

long chains of beta glucose molecules 1-4 glycosidic bond. Glucose chains form rope-like microfibrils layered to form a network

Question 43

How do every other glucose molecules rotate

Answer 43

through 180 degrees so that hydroxyl groups are adjacent

Question 44

Why do cellulose have hydrogen bonding

Answer 44

Gives tensile strength, ideal for providing structural support to plant cells