Carbohydrates Flashcards
What are monosaccharides?
the monomers that make up carbohydrates.
What is the structure of alpha glucose and beta glucose?
What are disaccharides?
Two monosaccharides are joined together by a glycosidic bond.
What are the bonds that form between monosaccharides?
glycosidic bond
Which sugars are reducing?
most monosaccharides and some disaccharides
How do you test for a reducing sugar?
Add Benedict’s reagent and heat using a water bath. If the solution goes from blue to red then a reducing sugar is present.
Which sugars are non-reducing?
most disaccharides
How do you test for a non-reducing sugar?
Add HCl and then heat in a water bath. Then add sodium hydrogen carbonate to neutralise the HCl. Add Benedict’s reagent and heat using a water bath. If the solution goes from blue to red then a non-reducing sugar is present.
What are polysaccharides?
many monosaccharides are joined together by glycosidic bonds formed in condensation reactions.
What is the function of glycogen?
The main source of energy for animals.
How does the structure of glycogen link to its function?
They have branched chains which can be readily hydrolysed by enzymes to release glucose. They are insoluble meaning they don’t change the water potential of the cell and cause water to move into the cells via osmosis. They are compact meaning they fit in small spaces like grains in the liver and muscles.
What is the function of starch?
the main source of energy for plants.
How does the structure of starch link to this function?
It is made of amylopectin which is a long-branched chain of alpha glucose which can be readily hydrolysed by enzymes to release glucose. It is also made of amylose which is a long unbranched chain of alpha glucose that has a coiled structure. This makes the starch compact which means it is good for storage. It is also insoluble meaning it does not affect the water potential of cells and cause water to move into the cell via osmosis.
What is the function of cellulose?
makes up the cell wall which offers support to the cell.
How does the structure of cellulose link to this function?
It is made up of beta glucose meaning the cellulose molecules form long unbranched chains. This offers the strength of the molecule. The cellulose molecules are cross-linked by many hydrogen bonds that need a lot of energy to break and they are grouped into microfibrils which offers even more strength.
