Carbohydrates Flashcards
What are carbohydrates used for?
- source + storage of energy
- structural function
What 3 element make up carbohydrates?
Carbon
Hydrogen
Oxygen
What are monosaccharides?
Soluble and sweet-tasting building blocks for more complex carbohydrates
What is the general formula for monosaccharides?
(CH20)n
Name 3 hexose monosaccharides.
Fructose
Galactose
Glucose
Glucose formula + function
- C6H1206
- main source of energy for respiration
- building blocks for larger carbohydrates
Properties of glucose
- small so easily transported in and out of cells through carrier proteins
- soluble so easily transported around an organism
- less reactive so break down must be catalysed and controlled by enzymes
Isomers of glucose
- alpha + beta glucose
- different hydroxyl group position
What is a polysaccharide of alpha-glucose?
Amylose
What is a polysaccharide of beta-glucose?
Cellulose
What is ribose?
- pentose sugar
- found in many important biological molecules like RNA + ATP
What are disaccharides?
Sugars formed by joining 2 monosaccharides in a condensation reaction creating a glycosidic bond
What makes up maltose?
2 alpha-glucose molecules
What is maltose used for?
Found in germinating seed as more complex carbohydrates are broken down for energy
What makes up sucrose?
Alpha-glucose + fructose
What is sucrose used for?
Transported in the phloem to provide sugars to parts of the plants
What is lactose made of?
Alpha-glucose + galactose
What is lactose used for?
Found in mammalian milk to provide energy for infant animals
How are glycosidic bonds named?
Based off which carbon atoms the bonds are between e.g maltose has a 1,4 glycosidic bond
What are polysaccharides?
Complex carbohydrates made up of multiple monosaccharides formed in a series of condensation reactions
What is a true polysaccharide?
A polysaccharide made up of 10+ monosaccharides
What is an oligosaccharide?
A polysaccharide made up of 3-10 monosaccharides
In what ways can a polysaccharide be broken down?
Either by taking off the monosaccharide at the end of the chain or by breaking in half over and over
How is excess chemical energy stored?
By forming alpha glucose polysaccharides
Why are alpha-glucose polysaccharides well-suited for energy storage?
- compact so a lot of energy can be stored in a small space
- insoluble in water so no impact on the water potential of a cell
- large so they do not diffuse out of the cell
- easily hydrolysed into alpha-glucose when energy is needed
