1.4 Carbohydrate: Polysaccharides Flashcards
The different types of polysaccharides: starch, glycogen, and cellulose How their structures relate to their functions
What are polysaccharides?
Complex carbohydrates made of many monosaccharides
What are examples of polysaccharides?
- Starch (branched/unbranched)
- Glycogen
- Cellulose
What is starch?
3 points
- A polysaccharide
- used by plants
- store glucose
What monosaccharide makes up starch?
Specifically
Alpha-glucose
What types of glycosidic bonds are in starch?
1-4 and 1-6
What are the two forms of starch chains?
- Unbranched
- branched
What are 5 reasons why starch is a good energy store?
- Insoluble - It does not affect the water potential of the cell, so water is not drawn in by osmosis
- Large - It cannot diffuse out of cells
- Many side branches - Allow enzymes to hydrolysis the glycosidic bonds easily to rapidly release glucose
- Coiled - This makes it compact so that a lot of glucose is stored in a small space
- Hydrolysis releases alpha-glucose monomers - these are readily used in respiration
What is glycogen?
A polysaccharide used by animals to store excess glucose
What monosaccharide makes up glycogen?
Alpha-glucose
What types of glycosidic bonds are in glycogen?
1-4 and 1-6
What are 5 reasons why glycogen is a good energy store?
- Insoluble - It does not affect the water potential of cells, and so water does not enter cells by osmosis
- Compact - A lot of glucose can be stored in a small space
- More highly branched then starch - Enzymes can easily hydrolyse the glycosidic bonds to rapidly release glucose
- Large - It cannot diffuse out of cells
- Hydrolysis releases alpha-glucose monomers - which are then used in respiration
What is cellulose?
A polysaccharide that provides structural support in plant cell walls
What monosaccharide makes up cellulose?
Beta-glucose
How are beta-glucose molecules arranged in cellulose?
Every other molecule is inverted
What type of bonds link cellulose chains?
Hydrogen bonds
What are microfibrils?
Bundles of cellulose chains
What are macrofibrils?
Bundles of microfibrils
What are 3 ways cellulose is adapted for its role?
- Long straight unbranched chains - To provide rigidity to the cell wall
- Hydrogen bonds - Cross link the chains to add collectible tensile strength
- Microphibrils - Provide additional strength
Where is cellulose found?
Plant cell walls
Where is starch found?
Plant starch grains
Where is glycogen found?
Animals
What is the monomer of cellulose?
Beta-glucose
What is the monomer of starch?
Alpha-glucose
What is the monomer of glycogen?
Alpha-glucose
