Carbohydrates Flashcards
What are the three types of carbohydrates called?
Monosaccharides, disaccharides, polysaccharides
What is the main function of monosaccharides?
To store energy within their bonds. When bonds are broken during respiration, energy is released.
Is glucose soluble or insoluble?
Soluble
What reaction do monosaccharides undergo to form larger carbohydrates?
Condensation reactions.
Are polysaccharides soluble or insoluble?
Insoluble
How are disaccharides and polysaccharides formed?
When 2 OH groups on different monosaccharides interact to form a strong covalent bond (glycosidic bond)
What does the reaction of a glycosidic bond also release?
A water molecule
Glucose + glucose
Maltose
Glucose + fructose
Sucrose
Glucose + galactose
Lactose
How is a glycosidic bond broken?
When water is added in a hydrolysis reaction
What’s the glycosidic bond in maltose?
1,4
What’s the glycosidic bond in sucrose?
1,2
What’s the glycosidic bond in lactose?
1,4
How do disaccharides release energy quick?
They are made up of two sugar molecules so they are easily broken down by enzymes in the digestive system to their monosaccharides and then absorbed into the bloodstream.
Why are disaccharides easily soluble in water?
Due to the presence of many hydroxyl groups. The hydroxyl groups form hydrogen bonds with the water molecules when dissolved in aqueous solutions.
What are 3 examples of polysaccharides?
Starch, glycogen, cellulose
What does it mean if a polysaccharides is branched?
This means that it increases the rate at which the polysaccharide can be broken down
Suitability of straight and coiled polysaccharides?
Straight- makes the molecules suitable for constructing cellular structures
Coiled- makes the molecules suitable for storage and more compact.
Why are starch and glycogen useful as storage polysaccharides?
They are compact- so large quantities can be stored
They are insoluble- so they have no osmotic effect
What is starch made up of, and explain
Amylose- unbranched helix shaped chain with 1,4 glycosidic bonds between alpha glucose molecules
Amylopectin- branched molecule containing 1,4 glycosidic bonds between alpha glucose molecules and 1,6 glycosidic bonds.
What is the benefit of of the branches of amylopectin?
The branches result in many terminal glucose molecules that can easily be hydrolysed for use during respiration or for storage.
Features of glycogen?
It is highly branched and not coiled. It contains both 1,4 and 1,6 glycosidic bonds/
What is the benefit of glucose being even more branched than amylopectin?
The branching provides more terminal glucose molecules which can either be added or removed by hydrolysis. This allows the quick storage or release of glucose to suit the demands of the cell
What is the benefit of glycogen being compact?
This means that much can be stored in a small space.
