1. Biological Molecules Flashcards
List 3 common examples of polysaccharides.
Starch
Glycogen
Cellulose
What is the principle role of carbohydrates?
production and storage of energy
What is the general formula of a carbohydrate?
CnH₂On
where n is any number between three and eight.
Number of hydrogen atoms is always twice that of Carbon and Oxygen
What 3 elements do all carbohydrates contain?
Carbon
Oxygen
hydrogen
How is maltose formed?
condensation of two glucose molecules
How is lactose formed?
condensation of a glucose molecule and a galactose molecule
How is sucrose formed?
condensation of a glucose molecule and a fructose molecule
What are monosaccharides?
monomers from which larger carbohydrates are made
List 3 common examples of disaccharides.
lactose
sucrose
maltose
What is the name of a 5c monosaccharide?
Pentose
Can you name 2 common examples of a 5c monosaccharide.
ribose
deoxyribose
What type of sugar is glucose?
Hexose.
what are the 2 types of glucose?
a-glucose
b-glucose
What is a glycosidic bond?
covalent chemical bonds that link carbohydrates to other molecules .
List the 2 most common features of monosaccharides.
sweet tasting
soluble
No.of carbon atoms - name - molecular formula
3 - Triose - C₃H₆O₃
4 - Tetrose - C₄H₈O₄
5 - Pentose - C₅H₁₀O₅
6 - Hexose - C₆H₁₂O₆
7 - Heptose - C₇H₁₄O₇
What is the above table an example of?
Monosaccharides.
What are carbohydrates as a monomer unit?
Monosaccharides
What do pairs of monosaccharides combine to form?
disaccharides
What do monosaccharides form when combined in much larger numbers?
polysaccharides
Glucose + Glucose combine to form?
maltose
glucose + fructose combine to form?
sucrose
glucose + galactose combine to form?
lactose
What are polysaccharides?
polymers, formed by combining together many monosaccharide molecules.
how are monosaccharides joined to create a polysaccharide?
by glycosidic bonds that were formed by condensation reactions
Why are polysaccharides insoluble?
they are very large molecules
What makes polysaccharides suitable for storage?
they are large insoluble molecules
What happens when polysaccharides are hydrolysed?
They break down into disaccharides or monosaccharides
where can starch be found?
give a common example.
many plants in the form of small granules or grains.
e.g chloroplasts
how is starch formed?
The joining of between 200 and 100,000 a-glucose molecules by glycosidic bonds in a series of condensation reactions.
When monosaccharides join what molecule is removed?
What is the reaction therefore called?
Water.
condensation reaction.
What is hydrolysis?
addition of water that causes breakdown.
what happens when water is added to a disaccharide under suitable conditions?
The glycosidic bond is broken which releases the constituent monosaccharides.
How do we test if a disaccharide is a reducing sugar?
Benedicts solution
How do we know if a disaccharide is non-reducing when using Benedicts solution?
the colour of the solution does not change when the benedicts reagent is used