Carbohydrates and Lipids A1 Flashcards
Define the term monomer with examples.
- small identical or similar molecules
- can be joined together to make larger molecules called polymers
- eg. monosaccharides (alpha and beta glucose), amino acids, nucleotides
Define the word polymer.
Large molecules made from joining many similar or identical monomers together.
Describe hydrolysis and condensation reactions.
- hydrolysis reactions involve adding one molecule of water to break the bond between two monomers
- condensation reactions join two monomer units together with the removal of one water molecule
Give the elements found in carbohydrates.
Carbon (C)
Hydrogen (H)
Oxygen (O)
Give the molecular formula for glucose.
C6-H12-O6
Be able to draw the structure of alpha and beta glucose.
Glucose + glucose =
maltose
Glucose + galactose =
lactose
Glucose + fructose =
sucrose
What bond is formed in the reaction of two monosaccharides?
glycosidic bond
What is the molecular formula of disaccharides?
C12 H22 O11 (due to the loss of 1 water molecule)
What is a polysaccharide?
- a type of polymer formed by joining many monosaccharides together
- storage - starch (plants) + glycogen (human)
- structural - cellulose
Describe the structure of amylose (starch)
(5)
- long and straight chains of alpha glucose which coil into a helix
- carbon 1:4 glycosidic bonds
- compact structure for storage
- insoluble so does not affect water potential
- does not diffuse out of cells
Describe the structure of amylopectin (starch)
(5)
- branched chain of alpha glucose molecules
- carbon 1:4 and 1:6 glycosidic bonds
- provides large SA for rapid hydrolysis by enzymes
- insoluble so does not affect water potential
- does not diffuse out of cells
How does glycogen differ to starch and why?
similar however:
1. shorter chains - more readily hydrolysed into glucose (quicker)
2. more branched
3. large SA
4. stored in muscles and liver
5. like starch glycogen is insoluble so does not affect water potential or diffuse out of cells.