Biological Molecules Wrong Answers Flashcards
explain what reducing sugars do
sugar donates electrons to reduce blue copper 2 sulphate to orange copper 1 oxide
why are lipids a better energy store than carbs
they provide twice as much energy as carbs upon oxidation. if fat is stored as lipids then the same amount of energy will be stored for less than half the mass so they are a lighter energy store
explain the effect of a changed amino acid in the active site of an enzyme
it may no longer bind to the substrate which will not be positioned correctly, if at all, in the active site
the effect of a changed amino acid in the allosteric site
it might not form hydrogen bonds with others in the active site so will change the tertiary structure so the substrate may no longer fit
why does ATP make enzymes function more readily
ATP provides a phosphate that can attach to another molecule and will lower the activation energy needed so the enzyme has less ‘work’ to do and will lower the Ea. even more readily
use of ions in the body
Fe2+ - make up hmg for oxygen binding
Na+ - co transport of glucose/amino acids because sodium is moved out by active transport which creates a sodium concentration gradient
PO43+ - DNA/RNA/ATP
- also joins nucleotides in phosphodiester bonds, used in ATP which provides energy, forms the hydrophilic part of the phospholipid bilayer and phosphorylates other compounds to make them more reactive
properties of water that make it important for organisms
high specific heat capacity, large latent heat of vaporisation, solvent, metabolite, cohesion for surface tension, cohesion supports columns of water in plants
water important in the cytoplasm of cells
reactive, polar molecule so acts as a universal solvent, metabolite in reactions
how is ATP formed
condensation reactions catalysed by ATP synthase between three phosphates, adenine and ribose
why is ATP a suitable energy source for cells to use (not in comparison to glucose)
releases energy instantaneously and phosphorylates other compounds to make them more reactive
role of dna polymerase
joins adjacent nucleotides through condensation reactions to form a phosphodiester bond
features of DNA to help with SCR
weak H bonds so strands easily separated and complementary base pairing allows accurate replication
why does DNA polymerase only work on 5 carbon end
enzymes have specific active sites so it is only complementary to the 5’ end shape so has to synthesise that way
