Kerboodle 3 Flashcards
i one positive inorganic ion important in human metabolism. ii
Positive: K+ / Na+ / Ca2+ / H+ ü
one negative inorganic ion available to plant roots in the soil.
Negative: NO3− / PO43− ü
2 a Describe one structural difference between:
i α-glucose and β-glucose 2
Hydroxyl (OH) group on carbon 1 is above the plane of the ring in β-glucose and below the plane of the ring in α-glucose.
a Describe one structural difference between: ii secondary and tertiary folding of proteins
Secondary involves H bonds only ü whereas tertiary involves other bonds (ionic, disulfide) ü OR secondary forms fibrous structures ü whereas tertiary forms globular structures ü OR secondary bonds form between the chemical groups either side of peptide bonds (–C=0 and –N–H groups) ü but tertiary bonds form between the side-chains of amino acid residues ü
a Describe one structural difference between iii amylose and glycogen.
Amylose forms a straight chain but glycogen is branched ü
b State one functional difference between:
i lipids and carbohydrates
Lipids used for thermal insulation / electrical insulation / buoyancy / source of metabolic water / cell membranes / waterproofing / steroid hormones / long-term energy store ü Carbohydrates used for cell signalling / cell walls / arthropod exoskeleton / antigens / short term energy store ü
b State one functional difference between: ii DNA polymerase and RNA polymerase
DNA polymerase for DNA replication ü RNA polymerase for transcription ü
b State one functional difference between: iii collagen and elastin.
Collagen, inflexible / in bone / tendons ü Elastin stretchy / in ligaments / lungs / bladder ü
b Describe how you could show the existence of a carbohydrate other than reducing sugar in bananas under the microscope.
Add iodine in potassium iodide solution / I2 in KI (aq) ü Reacts with starch / amylose / amylopectin ü Colour changes from orange to blue–black ü
