Chapter 3- Carbohydrates Flashcards
What type of molecule is a carbohydrate?
A polymer
What is the monomer that makes up carbohydrates?
Monosaccharides
What type of monosaccharide is glucose
Hexose, has 6 carbons
What are the two forms of glucose?
Alpha and beta
What is the difference between alpha and beta glucose?
In alpha, the OH on carbon 1 is on the bottom
In beta, the OH on carbon 1 is on the top
Why is glucose soluble?
It is a polar molecule
What type of molecule is ribose?
A pentose monosaccharide, has 5 carbons
What 3 elements make up carbohydrates?
1) oxygen
2) carbon
3) hydrogen
What do 2 monosaccharides joined together form?
A disaccharide + water
What happens during the synthesis of a disaccharide ?
A hydrogen atom on one monosaccharide bonds to the OH group on another, releasing a molecule of water.
What type of reaction is the formation of disaccharides?
A condensation reaction
What type of reaction is the break down of disaccharides?
A hydrolysis reaction
What type of bond joins monosaccharides together?
A glycosidic bond. In maltose, it is alpha 1,4 glycosidic
What does two alpha glucose molecules joined together form?
Maltose
What does an alpha glucose and fructose joined together form?
Sucrose
What forms when you join an alpha/ beta glucose and galactose?
Lactose
What is a polysaccharide
When more than 2 monosaccharides join together
What is starch?
Plants store glucose as starch. It is a mixture of amylose and amylopectin. Starch is insoluble in water, so it doesn’t cause water to enter cells by osmosis so it is good for storage.
What is amylose?
A long unbranded chain of a- glucose. The angles of the glycosidic bonds give it a coiled structure. This makes it compact, so it’s good for storage because you can fit more in a small space. It only contains alpha 1,4 glycosidic bonds
What is amylopectin?
A long, branched chain of a-glucose. It’s side branches allow enzymes that break down the molecule to get at the glycosidic bonds easily. This means glucose can be released easily. The chains are are alpha 1,4 glycosidic bonds and the branches are alpha 1,6 glycosidic bonds.
What is glycogen?
The main energy storage material in animals. Animals store excess glucose as glycogen in cells.
2) it’s structure is similar to amylopectin however it has many more branches ( alpha 1,6 glycosidic bonds) coming off it. This means stored glucose can be released very quickly which is important for animals.
3) it is also a very compact molecule so good for storage.
What is cellulose
1) it is a major component of cell walls in plants
2) it is made of long, unbranched chains of beta-glucose. When beta-glucose molecules bonds, they form straight chains and each alternate glucose monomer is flipped due to the position on the OH group. It contain beta 1,4 glycosidic bonds.
3) the cellulose chains are linked together by hydrogen bonds to form strong fibres called microfibrils. The strong fibres mean cellulose provides structural support for cells.
