Carbohydrates- Monosaccharides Flashcards
What is the test for sugars?
Benedicts test
What is the benedicts test for reducing sugar?
Add benedicts reagent to a sample and heat in a water bath. If the test is positive it will form a clouded precipitate. The colour should change along a colour scale from blue to brick red. Higher concentration of sugar the further along the scale it will be.
What will happen if there is a reducing sugar present?
It forms an insoluble red precipitate.
What is a polymer?
A long complex chain made up of multiple monomers joined together.
What are examples of monomers?
Amino acids
Nucleotides
Monosaccharides
What is a condensation reaction?
This where two molecules join together and form a new bond, and a water molecule is released.
What bond forms between two monosaccharides?
Glycosidic bond
What does a glucose and fructose molecule form?
Sucrose
What does glucose and galactose form?
Lactose
What does two glucose molecules form?
Maltose
What is benedicts test for non reducing sugar?
First break into monosaccharides.
Add dilute hydrochloric acid and carefully heat in a waterbath. Then neutralise it by adding sodium hydrogencarbonate. Then carry out benedicts test as usual.
What is a polysaccharide?
Loads of sugars joined together.
What are three polysaccharides?
Cellulose
Glycogen
Starch
Why do plants use starch?
Starch is an energy storage molecule for plants. They store excess glucose as starch.
How does amylose and amylopectin affect storage of glucose?
Amylose has a coiled structure and is compact which means you can fit more in a small space.
Amylopectin has a branched structure. These branches allow the enzymes to reach the glycosidic bonds easily and release the glucose faster.
