Carbohydrates

What are monomers?

Small units that can bond together to form larger molecules

What are polymers?

A chain of monomers bonded together

Which sugars are simple carbs?

Monosaccharides

Disaccharides

Which sugars are complex carbs?

Polysaccharides

What is the name for 5 and 6 sided monosaccharides?

Pentose sugars

Hexose sugars

Difference between alpha and beta glucose?

Alpha:

The H is at the top on the right side

The OH is at the bottom

Beta: (right side only)

The OH is at the top

The H is at the bottom

What is a condensation reaction?

The formation of a larger biomolecule with the by-product of water

What is hydrolysis?

The breakdown of large biomolecules into smaller molecules, through the addition of water

What are the properties of disaccharides?

• Made up of 2 monosaccharides

• Joined by glycosidic bonds

• Formed with a condensation reaction

Glucose and glucose combine to make?

Maltose and water

Glucose and galactose combine to make what?

Lactose and water

Glucose and fructose combine to make what?

Sucrose and water

How are carbons numbered on sugars?

In a clockwise direction starting from after the oxygen

What would (1,4) refer to in terms of a glycosidic bond?

The 1 means that carbon 1 on the first sugar has bonded to an oxygen which is bonded to carbon 4 on another sugar

Which polysaccharides do you need to know?

Glycogen

Cellulose

Starch

Properties of starch?

• Formed from alpha glucose

• Comes in amylose and amylopectin

• It is an insoluble store of glucose

Properties of amylose?

• 20% of starch is stored as amylose

• Straight chain polymer (1,4 glycosidic bonds)

• Forms a helix structure (compacts to fit lots of glucose)

Properties of amylopectin?

• 80% of starch is stored as amylopectin

• Branched chain polymer (1,4 bonds and random 1,6 bonds)

• High surface area from chained structure makes it easier for enzymes to break it down during hydrolysis to release glucose

Where is starch found?

In the chloroplasts of plant cells

What is gelatinisation?

Starch and water are subjected to heat, causing the starch granules to swell

What is retrogradation?

The starch molecules re-associate and form and ordered structure (water molecules are released) (this happens when the temperature cools)

Properties of glycogen?

• Made of alpha glucose

• Many branched structure

• Insoluble store of glucose

• Found in liver and muscle cells

• Branches increase SA for hydrolysis to release glucose

• Has 1,4 and 1,6 glycosidic bonds

Properties of cellulose?

• Made of beta glucose

• Found in cell wall of plant cells

• Insoluble

• Resists against osmotic pressure, providing structure to the cell

How is the bonding in cellulose related to its structure?

• 1,4 glycosidic bonds of BETA glucose

• Cellulose forms in long straight chains held parallel to each other by hydrogen bonds

• Multiple chains of them forms a fibril

How does the structure of cellulose relate to its function?

• The many hydrogen bonds between chains creates structural strength

• It is insoluble so it does not affect water potential