Biological Molecules (complete) Flashcards
Monomers of: Maltose, Sucrose and Lactose.
Maltose: Glucose-Glucose
Sucrose: Glucose-Fructose
Lactose: Glucose-Galactose
Test for Non-reducing Sugars.
Add HCl. Heat for few mins. Add sodiumhydrogencarbonate. Add Benedict’s solution. Heat for few mins.
Blue-Green-Orange-Brick red.
Test for Reducing sugars.
Add Benedict’s solution. Heat for a few minutes.
Blue-Green-Orange-Brick red.
Test for Starch.
Add Iodine.
Amber-Blue/Black
Test for Proteins.
Add Biuret A+B.
Blue-Purple/Lilac.
Test for Lipids.
Add Ethanol.
Colourless-Milky white
Alpha vs Beta glucose - Similarities
Same Molecular Formula.
Both formed into polymers through condensation reactions, which contain glycosidic bonds.
Define:
- polar molecule
- hydrogen bond
- glycosidic bond
- metabolism
- molecules with an uneven distribution of charge.
- a bond formed between polar molecules.
- a covalent bond forming between sugar molecules.
- the combination of chemical reactions taking place within a cell.
Reducing sugar vs Non-reducing sugar.
Reducing - ‘donate’ electrons to other molecules in chemical reactions.
Non-reducing - don’t ‘donate’ electrons during chemical reactions.
What are the properties of starch?
Branched chain - allows the molecule to be easily hydrolysed by many enzymes simultaneously.
Coiled shape - allows the molecule to be easily compacted, so large amounts of it can be stored in small spaces.
Insoluble - won’t affect the cells water potential, and it can’t diffuse out of the cell.
Large - the molecule can’t diffuse out of the cell.
What are the properties of cellulose?
Straight, unbranched chain - allows for hydrogen bonds to form, increasing strength of molecule.
Grouped molecules - form microfibrils, which when grouped form fibres, providing more strength to the molecule.
What are the properties of glycogen?
Insoluble - it won’t affect the cells water potential, and can’t diffuse out of the cell.
Branched chain - allows the molecule to be easily hydrolysed by many enzymes simultaneously.
Coiled shape - allows the molecule to be compacted easily to store large amounts in small areas.
Large - the molecule can’t diffuse out of the cell.
Properties and uses of Triglycerides
Properties:
- contains ester bonds.
- contains carbon, hydrogen and oxygen.
- the fatty acids can be saturated or un-saturated.
- they only contain a hydrophobic region.
- they are formed by condensation reactions.
- they contain three fatty acids and glycerol.
- non-polar molecule, so won’t affect water potential of cell.
Uses:
- large form of energy storage due to high number of C-H bonds.
- used for insulation and protection of organs.
- important source of water due to release of water when oxidised as high H:O ratio.
Properties and uses of Phospholipids
Properties:
- contains ester bonds.
- contains carbon, hydrogen, oxygen and phospholipids.
- their fatty acids can be saturated or un-saturated.
- they contain both a hydrophobic and hydrophilic region.
- they are formed by condensation reactions.
- they are polar molecules, which form a bilayer with an aqueous environment.
- they contain glycerol, two fatty acids and a phospholipid group.
Uses:
- help maintain stability and strength of cells.
- act as semi-permeable barrier, helping maintain proper balance of substances within cell.
- aids protection against ‘environmental insults’.
- forms the phospholipid bilayer.
Uses of Lipids
- Energy source
- Insulation.
- Protection.
- Waterproofing.