Carbohydrates (C) Flashcards
Polysaccharides
Features of polysaccharides
Do not taste sweet
Insoluble in water
Function as storage or structural molecules
Joined by glycosidic bonds
What molecules is starch made up of?
Alpha glucose molecules
Where is starch found?
It is found in plants
What type of branches are in starch?
Long, branched chains
What is the function of starch?
A storage molecule
An insoluble store for glucose
Why is starch ideally suited to its function as a storage compound?
The molecule’s helical shape alloaws it to compactly store a lot of glucose in a small space
The branched structure increases the surface area for rapid hydrolysis back to glucose
Its insolubility makes it osmotically inactive, preventing it from affecting water balance within the cell
How to do the iodine test?
Add 2-3 drops of iodine/potassium iodide solution
If starch is present a blue/black colour is produced
If no starch is present the iodine solution remains orange/yellow
What is the iodine test?
A test to detect if a sample has starch present
What molecules is glycogen made up of?
Alpha glucose
What type of branches are in glycogen?
Highly branched with many free ends
Where is glycogen found?
It is found in the cytoplasm of animal cells
Mainly in the liver and muscle tissues
What is the function of glycogen?
A storage molecule
An insoluble store for glucose
Why is glycogen ideally suited to its function as a storage compound?
Highly branched and having many free ends means it can undergo rapid hydrolysis to release glucose for respiration
It’s many free ends means that it can be compacted easily storing a large amount of glucose in a small space
Insoluble so does not affect water potential
Too large to diffuse out of the cell
What does the branches’ structure mean for glycogen?
Can be hydrolysed more rapidly to release glucose for respiration
Can be compacted easily
What molecules is cellulose made up of?
Beta glucose
