Carbohydrates

Question 1

What do carbohydrates contain

Answer 1

Carbon, hydrogen and oxygen

Question 2

Glucose formula

Answer 2

C6H12O6

Question 3

What is a monosaccharide

Answer 3

1 unit

Question 4

What is a disaccharide

Answer 4

2 units

Question 5

What is a polysaccharide

Answer 5

Many units

Question 6

Examples of monosaccharides

Answer 6

Glucose, fructose and galactose

Question 7

Examples of disaccharides

Answer 7

lactose, sucrose, maltose

Question 8

Examples of polysaccharides

Answer 8

glycogen, starch, cellulose

Question 9

Example of a hexose monosaccharide (6 car bonds)

Answer 9

Glucose

Question 10

Is glucose soluble in water

Answer 10

Yes

Question 11

why is glucose soluble in water

Answer 11

due to the hydrogen bonds that form between the hydroxyl groups and water molecules.

Question 12

Difference between alpha and beta glucose

Answer 12

Alpha = hydrogen Above carbon 1
Beta = hydrogen Below carbon 1

Question 13

Draw alpha glucose

Answer 13

Question 14

Draw beta glucose

Answer 14

Question 15

General properties of monosaccharides

Answer 15

White crystalline solids
• Dissolve in water to form sweet tasting solutions

Question 16

What can monosaccharides be categorised into

Answer 16

Trioses
Tetroses
Pentoses
Hexoses

Question 17

Properties of pentoses (ribose)

Answer 17

Used in the synthesis of nucleic acids (RNA and DNA), co-enzymes (NAD, NADP, FAD) and ATP

Question 18

What type of bond is formed between a carbon 1 and a carbon 4 in a condensation reaction

Answer 18

Covalent - 1,4 glycosidic bond

Question 19

Monomers to make maltose

Answer 19

A glucose + a glucose

Question 20

Monomers of sucrose

Answer 20

a-glucose + fructose

Question 21

Monomers of lactose

Answer 21

B Glucose + galactose

Question 22

What is starch

Answer 22

Main storage polysaccharide in plants

Question 23

Properties of starch

Answer 23

Pure starch is white, tasteless, and odourless
• It is insoluble in cold water or alcohol

Question 24

How is starch formed

Answer 24

when alpha glucose monomers are joined together by glycosidic bonds during condensation reactions

Question 25

Two constituents of starch

Answer 25

Amylose + amylopectin

Question 26

How is amylose formed

Answer 26

Alpha 1-4 glycosidic bonds

Question 27

Properties of amylose

Answer 27

- un branched = no need for rapid release of glucose in plants - coil shape = compact = lots can be stored in a small space - insoluble = doesn’t affect w.p.

Question 28

amylopectin bonds

Answer 28

Alpha 1-4 and 1-6 glycosidic bonds

Question 29

Properties of amylopectin

Answer 29

- insoluble = doesn’t affect w.p - few branches = no need for rapid release of glucose - coiled = compact + lots can be stored in a small space

Question 30

What is glycogen

Answer 30

Main storage polysaccharide in animals and fungi (animal equivalent of starch)

Question 31

Bonds in glycogen

Answer 31

alpha 1,4 and 1,6 glycosidic bonds

Question 32

Properties of glycogen

Answer 32

- insoluble so no effect on w.p. - compact = able to store large amounts of energy - highly branched = lots of ends for adding / removing glucose - metabolically inactive

Question 33

Cellulose properties

Answer 33

Insoluble Inert High tensile strength bc hydrogen bonds = hard to digest cellulose = requires specific enzyme. Flexible

Question 34

Compare glycogen and amylopectin

Answer 34

Glycogen is: - more branched = more free ends where glucose can be added or removed (so) speeds up glucose release - more coiled = more compact

Question 35

What is cellulose

Answer 35

Main structural constituent of plant cell walls

Question 36

Importance of cellulose in plants

Answer 36

cell wall needs to be strong enough to enable each cell to support the whole plant

Question 37

Cellulose bonding stuff

Answer 37

Alternate beta glucose molecules are rotated 180 degrees 1-4 glycosidic bonds to form chain + hydrogen bonds between chains

Question 38

What is a cellulose chain called

Answer 38

Microfibril

Question 39

How is the cell wall formed

Answer 39

Lots of microfibrils together = macrofibril Macrofibrils cross link to form the cell wall

Question 40

Importance of cellulose having high tensile strength

Answer 40

Allows plant to be turgid

Question 41

Draw ribose

Answer 41

Question 42

Answer 42

A

Question 43

Answer 43

Question 44

Answer 44

Question 45

ii

Answer 45

Question 46

Answer 46

Question 47

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Question 48

Answer 48

Question 49

Answer 49