Carbohydrates

Question 1

Carbohydrates

Answer 1

Monosaccharides
Disaccharides
Polysaccharides

Question 2

Monosaccharides

Answer 2

They are monomers

Question 3

Types of Monosaccharides

Answer 3

Triose: Glyceraldehyde

Pentose: Deoxyribose, Ribose

Hexose: Glucose, Fructose, Galactose

Question 4

Alpha Glucose

Monosaccharide

Answer 4

Alpha Glucose: OH group on C1 lies below the plane of the ring - Forms Starch

Question 5

Beta Glucose

Monosaccharide

Answer 5

Beta Glucose: OH group on C1 lies above the plane of the ring - Forms Cellulose

Question 6

Galactose

Monosaccharide

Answer 6

Isomer (Same formula) of Glucose

OH on C4 up

6-sided ring

Question 7

Fructose

Monosaccharide

Answer 7

Isomer (Same formula) of Glucose

5-sided ring

Question 8

Disaccharides

Answer 8

Monosaccharide + Monosaccharide

Bonded by glycosidic bonds in condensation reactions

OH group lost from one monosaccharide and H lost from the other. Leaving a glycosidic bond named after the linked carbon e.g 1-4 bond in maltose

Question 9

Maltose

Disaccharide

Answer 9

Monosaccharides:
Alpha Glucose - Alpha Glucose

Used in seed germination

Question 10

Sucrose

Disaccharide

Answer 10

Monosaccharides:
Alpha Glucose - Fructose

Transported in phloem of flowering plants

Question 11

Lactose

Answer 11

Monosaccharides:
Glucose - Galactose

Found in mammalian milk

Question 12

Polysaccharides

Answer 12

Large complex molecules (Polymers) made from bonding many monomers

Used for:
Energy storage - (Starch in plants, glycogen in animals)
Structural support - (Cellulose in plant cell walls, chitin in insects)

Question 13

Starch (Amylose)

Answer 13

Structure:

• Long, linear, unbranched chain of alpha glucose molecules
• Wound into a tight coil
• 1-4 glycosidic bonds

Properties/Function:

• Very compact and a good energy store
• Not efficient energy release due to only two ends for reactions to occur at

Question 14

Starch (Amylopectin)

*Think “peck”–>bird–>branches

Answer 14

Structure:

• Long branched chain of alpha glucose
• 1-4 glycosidic bonds in main chain, 1-6 glycosidic bonds in side branches

Properties/Function:

• Side branches allow enzymes to reach and break down bonds easily
• Glucose released quickly

Question 15

Glycogen

Answer 15

Structure:

• Short branched chain of alpha glucose
• 1-4 glycosidic bonds in main chain, 1-6 glycosidic bonds in side branches

Properties/Function:
-Rapid release of glucose

Question 16

Cellulose

Answer 16

Structure:

• Long, straight chains of alternating Beta glucose monomers rotated through 180°
• 1-4 glycosidic bonds

Properties/Functions:

• Hydrogen bonds form between parallel chains forming microfibrils
• Many microfibrils form macrofibrils which have high mechanical strength
• Many macrofibrils form cellulose fibres which crisscross each other for strength and rigidity

Question 17

Chitin

Answer 17

Structure:

• Subunits of alternating Beta glucose monomers rotated through 180°
• 1-4 glycosidic bonds
• Subunits known as glucosamine
• OH on C2 is replaced by acetylamine group

Properties/Functions:

• Acetylamine group allows more hydrogen bonds to form
• Chitin stronger than cellulose
• Strong
• Lightweight
• Waterproof