Carbohydrates Flashcards
What is the general function of carbohydrates?
Source of energy and structural function
What are monosaccharides?
Consist of only 1 sugar molecule. General formula of (CH2O)n.
What is glucose?
A hexose sugar that is the main energy source in respiration and makes up bigger carbs.
What are the properties of glucose?
- Small for easy transport in and out cells
- Soluble (blood transport)
- Less reactive - breakdown controlled by enzymes
What is the difference between the 2 glucose isomers?
The position of the OH group. Amylose made of alpha, cellulose made of beta
What type of bond joins monosaccharides?
Glycosidic bond in a condensation reaction.
Which are reducing and non reducing sugars?
Reducing: maltose and lactose
Non reducing: sucrose
What are polysaccharides?
Complex carbohydrate polymers formed from a series of condensation reactions
How is ATP made?
Energy released from glucose respiration
Why are starch glycogen well suited for energy storage?
- Compact
- Insoluble in water (not affect water potential)
- Large (not diffuse out)
- Easily hydrolysed
What is starch?
Main plant energy store, made up of alpha glucose. Made up of amylose and amylopectin
What is amylose?
Long chain of alpha glucose, coils into helix. Hydroxyl groups on inside with H bonds between them - maintain structure and decrease solubility
What is amylopectin?
Long chained molecule of alpha glucose. Also has H bonds. Has side branches with more accessible ends to break down.
What is glycogen?
Only made up of alpha glucose, smaller chains so coils less. Highly branched so more compact.
What is the main polysaccharide energy storage in animals?
Glycogen because higher metabolism so hydrolysed quickly for respiration.
How does cellulose stay in a long, straight chain?
Inversions of 180’ forming glycosidic bonds. H bonds allow chains to run parallel to each other.
How are OH groups arranged in cellulose?
Close together with H bonds between in beta glucose from adjacent chains
How are microfibrils formed?
Bundle of cellulose chains form microfibrils, which then bundle to form macrofibrils, which wrap around plant cells in layers at various angles.
Why is cellulose a good material for cell walls?
- Not easily digested and hard to break down
- High tensile strength due to many bonds
- Macrofibrils can be reinforced for waterproofing/extra support.
What are the spaces between macrofibrils for?
Water passage and ions - fully permeable
