Unit 1 pracs Flashcards
Caffeine on Daphnia
Effect of caffeine of the heart rate of Daphnia
Caffeine on Daphnia: IV + DV
IV: caffeine concentration
DV: heart rate of Daphnia
Caffeine on Daphnia: controls - V + how
CV: temperature - temp controlled room + beaker in ice / volume of solution (pond water, caffeine) - measuring beaker + pipette / sample of Daphnia - same - collect from same batch (age/size) / time - stop watch
Caffeine on Daphnia: Control group
CG: Daphnia exposed to no caffeine - heart rate recorded / data can be compared to experimental group
Caffeine on Daphnia: procedure
beaker (Daphnia in pond water) into ice - 30 mins / collect Daphnia from beaker - kept at a constant 25 degrees / using pipette put Daphnia on cotton wool on slide / add two drops of pond water / add volume+concentration of caffeine to the slide / use dissecting microscope observe + record results per minute / repeat experiment
Caffeine on Daphnia: evaluation
Daphnia were same - validity / heat from microscope lamp - increase heart rate / enough data collected / high concentration = dead Daphnia /counting heart beats - stroboscope / reliability
Vitamin C
The Vitamin C content of fruit juice
Vitamin C: IV + DV
IV: type of fruit
DV: amount of vit C
Vitamin C: IV + DV
IV: type of fruit
DV: amount of vit C in juice
Vitamin C: CV + how
CV: temperature - controlled room - water bath / volume (1cm3) of DCPIP - pipette / sample of vit c - same source / shaking tubes - count / end result - blue to clear colouring
Vitamin C: control group
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Vitamin C: procedure
1cm3 DCPIP in test tube / using burette add 1% vit c soln drop by drop / shake tube / keep adding until blue turns clear / record volume of solution needed to decolourise / repeat - calculate mean - on other fruit
Vitamin C: evaluation
difficult controlling temp / amount of shaking - adds oxygen = restores DCPIP / end point - hard to judge / loss of solution when transferring
Temp on membranes
The effect of temperature of cell membranes
Temp on membranes: IV+DV
IV: temperature of water
DV: % transmission of light through resulting solution
Temp on membranes: CV + how
CV: volume distilled water - measuring beaker+pipette / time - stop watch / size of beetroot piece - measured then cut / same sample - same beetroot - batch
Temp on membranes: procedure
using cork borer + knife cut beetroot 1cm / place in distilled water overnight /
Temp on membranes: procedure
using cork borer + knife cut beetroot 1cm / place in distilled water overnight / wash + blot dry / place boiling tubes with distilled water in water baths / when at temp add beetroot pieces- 30 mins / remove beetroot - shake tube / set colorimeter 100% absorbance - blue+green filter / calibrate using cuvette
Temp on membranes: procedure
using cork borer + knife cut beetroot 1cm / place in distilled water overnight / wash + blot dry / place boiling tubes with distilled water in water baths / when at temp add beetroot pieces- 30 mins / remove beetroot - shake tube / set colorimeter % absorbance - blue+green filter-cuvette+ distilled water - reads 0 absorbance / 2cm3 of beetroot soln into cuvette - colorimeter / record results / repeat for other pieces
Temp on membranes: evaluation
beetroot has skin - affecting S.A. / maintaining temp / accurate reading on colorimeter / accurate size of beetroot / different parts of roots / same time at all temps
Enzyme effect
Effect of changing the enzyme concentration on the rate of reaction
Enzyme effect IV+DV
IV: concentration of enzyme
DV: time taken for enzyme to break down a substrate
Enzyme effect CV + how
CV: temperature / volume of enzyme / volume of substrate / concentration of substrate / pH
Enzyme effect procedures
5cm3 of protein suspension (
