Biological Molecules - do on 13/06

List all the properties of water and how it applies to its function

- polar which allows it to be a solvent for other polar molecules and ions
- high specific heat capacity due to hydrogen bonds so large amount of energy required to warm it up
- high latent heat of vaporisation due to hydrogen bonds so evaporation produces a cooling effect
- cohesion due to hydrogen bonds creates continuous columns of water in xylem vessels in transpiration
- adhesion to other polar surfaces helps water move up xylem walls
- ice is less dense than water so it forms an insulating layer over it allowing aquatic life to survive

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Match Practice Test Progress & Stats

Term	Definition
List all the properties of water and how it applies to its function	- polar which allows it to be a solvent for other polar molecules and ions - high specific heat capacity due to hydrogen bonds so large amount of energy required to warm it up - high latent heat of vaporisation due to hydrogen bonds so evaporation produces a cooling effect - cohesion due to hydrogen bonds creates continuous columns of water in xylem vessels in transpiration - adhesion to other polar surfaces helps water move up xylem walls - ice is less dense than water so it forms an insulating layer over it allowing aquatic life to survive
List properties of starch and glycogen and how they help with function	Starch: - insoluble so doesn't affect the water potential of cells, preventing water from moving in by osmosis - large so cannot diffuse out of cells - compact so large amounts can be stored in a small space - amylopectin is branched so glucose can be released more rapidly Glycogen: - also insoluble, large and compact for the same reasons - highly branched so glucose can be released very quickly
Test for reducing/non-reducing sugars	Reducing: - add benedict's solution - blue to green-red precipitate, closer to red means higher concentration of reducing sugars Non-reducing (if no reducing present): - boil with dilute HCl - neutralise with NaOH - add benedict's solution same positive result
Test for starch	- add iodine solution - orange to blue-black
Test for lipids	- add ethanol + water - white emulsion
Four components of an amino acid	- amino group - carboxyl group - R group - hydrogen
Describe all structures of a protein + bonds	Primary: amino acid sequence joined by peptide bonds Secondary: folded into alpha helix or beta pleated sheet with hydrogen bonds Tertiary: 3D shape created by hydrogen bonds, hydrophilic and hydrophobic interactions between polar R groups, disulfide bonds, and ionic bonds Quaternary: joining of two or more polypeptide chains, same interactions as tertiary