2 - molecular biology Flashcards
explain importance of hydrogen bonding for living organisms [8]
- cohesion in H2O allow molecules to stick (due to H-bonding)
- useful in transpiration stream to bring water up the xylem
- adhesion of H2O to polar molecules or surfaces (due to H-bonding)
- can help keep leaves moist
- high latent heat of vaporization, much energy needed for evaporation
- acts as good coolant
- solvent properties due to H-bonding with polar/hydrophilic molecules
- high SHC so there are little temp. fluctuations for organisms with water habitats
compare energy storage abilities of glycogen and triglycerides (include their properties) [3]
- glycogen is a carbohydrate and is soluble
- triglycerides are lipids are are insoluble
glycogen: short-term storage, energy is not pure, easy to transport
trigly: long-term storage, energy is pure, difficult to transport
mnemonics for drawing biological molecules (carbs, fatty acids, nucleic acid)
carbs
- ribose 5C, -OH UDD (C 1-3)
- a-glucose 6C, -OH DDUD (C 1-4)
- b-glucose 6C, switch -OH UDUD (C 1-4)
fatty acid
- no C=C is saturated
- yes C=C is unsaturated
nucleic acid
- ribose, C1 base, C5 phosphate
- phosphodiester from C3 to phosphate
- H-bonding between bases
- upright acid side is 5’ to 3’
- upside down acid side is 3’ to 5’
list general functions of non-membrane proteins [4]
- enzymes
- hormones
- histones
- movement/contraction (actin myosin)
- immunity
use of lactase in lactose-free milk production [8]
- lactose is a disaccharide found in milk
- can be broken down by lactase into glucose and galactose
- lactase can be added into milk to reduce lactose content
- accommodate those who are lactose-intolerant
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- glucose and galactose are monosaccharides, so sweeter
- lactose-free milk is generally sweeter, less sugar needed
- bacteria ferment glucose and galactose quicker, so production of yoghurt/cheese is quicker