Carbohydrates Flashcards
What do Carbohydrates Contain?
Carbohydrates contain carbon, hydrogen, and oxygen
What is the ratio of hydrogen atoms to oxygen atoms?
There are twice as many hydrogen atoms as oxygen atoms (the same as water)
What are the three types of carbohydrates?
Monosaccharides
Disaccharides
Polysaccharides
What are monosaccharides?
Monosaccharides are single sugars. Different monosaccharides contain different numbers of carbon atoms.
What are Disaccharides?
Disaccharides are carbohydrates that contain two monosaccharides joined together by a glycosidic bond during a condensation reaction.
What are polysaccharides?
Polysaccharides are large molecules that contain many monosaccharides
Name some monosaccharides:
Glucose
Fructose
Galactose
Name some disaccharides:
Sucrose
Lactose
Maltose
Name some polysaccharides:
Storage - Starch and glycogen
Structure - Cellulose and chitin
What is glucose’s formula?
C6H12O6
What are the two isomers of glucose?
Alpha (DDUDU)
Beta (UDUDU)
What is maltose made up of?
Two alpha glucose joined by a glycosidic bond - The two OHs on the bottom change to an oxygen
What is sucrose formed by?
Alpha glucose and fructose
What is the test for sugars?
Benedict’s solution - starts as light blue and goes orange if simple sugars are present.
What is a reduction?
A reduction is gain of electrons or hydrogen
What is a glycosidic bond?
A glycosidic bond is a chemical bond formed as a result of condensation between two monosaccharides
What is amylose made of?
Long chains of alpha glucose
What is starch?
A substance found in plants that makes up for the most important fuels in the human diet. It is present in 30% of what we eat and is a mixture of amylose and amylopectin.
How do you test for starch?
A drop of iodine solution will turn blue/black if starch is present
What is starch used for in plants?
Starch in plants is used for storage in seeds and in short term such as overnight when photosynthesis cannot occur.
Why is starch good for storage in plants?
Starch is insoluble and does not easily diffuse out of cells or affect water potential or osmosis. It can easily be broken down by enzymes that plants have.
How do animals/humans break down starch?
Humans have a digestive enzyme called amylase that hydrolyses starch to maltose which is then hydrolysed to glucose.
Where is glycogen stored?
It is stored in the liver where it is slowly released to maintain blood glucose concentration
What are the two types of glycosidic bonds?
1,4 and 1,6
What is the purpose of cellulose?
The purpose of cellulose is the strength of the plant cell wall. Cellulose is a polysaccharide and a polymer of glucose. The monomer in cellulose is beta glucose. The glucose in cellulose are beta so the oxygen bond alternates top to bottom
Why is cellulose good?
It can stretch due to its structure but is also strong enough to support the plant
