carbohydrates Flashcards
1
Q
what are carbohydrates?
A
- organic molecules that contain only carbon (C), hydrogen (H), and oxygen (O).
- an excellent source of chemical energy for living cells.
2
Q
what are monosaccharides?
A
- smallest carbohydrates, simple sugars. e.g, glucose, galactose and fructose
- monomers of carbohydrates
- made up of one carbohydrate monomer
- carbon, hydrogen and oxygen, 1:2:1
3
Q
what is glucose commonly used for?
A
- source of chemical energy by the cells of most organisms during cellular respiration
- sourced from the digestion of larger carbohydrate polymers such as starch.
- have an -OH group, making it both polar and hydrophilic.
4
Q
what are disaccharides?
A
- two monosaccharides bonded together.
- e.g, sucrose which consists of glucose and fructose.
5
Q
how are monosaccharides chemically bonded together?
A
dehydration reactions chemically bond monosaccharides together, the bond that is formed between monosaccharides is called a glycosidic linkage.
- e.g, fructose + glucose -> sucrose
6
Q
what are polysaccharides?
A
- complex carbohydrate that forms when simple sugars bind together to form polymers consisting of hundreds or thousands of monomers
- important for energy storage and building physical structures in organisms.
1. starch
function ; store chemical energy in plants
e.g ; potato plants contain starch in large amounts in underground tubers
2. glycogen
function ; store chemical energy in animals
e.g, liver cells in humans contain glycogen
3. cellulose
function ; form rigid structures in plants
e.g, tough cell walls of plants.
4. chitin
function; hard exoskeleton in some animals
e.g, crabs