# Unit 3 Applied Science Experimental Methods

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Hypothesis:
As light intensity increases, more ______ bubbles are released, indicating the rate of ___________ has increased
As light intensity increases, more oxygen bubbles are released, indicating the rate of photosynthesis has increased
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What equipment is needed?
Pond weed, boiling tube, water, lamp, ruler, timer, heat shield (justify the use of this equipment in the exam)
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Procedure:
1. Leave the pondweed for _ minutes to reach the new light intensity
2. Count the number of bubbles given off in _ minutes
1. Leave the pondweed for 5 minutes to reach the new light intensity
2. Count the number of bubbles given off in 1 minute
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3. Move the lamp __cm further back
4. Leave the pondweed for _ minutes to reach the new light intensity
5. Count number of bubbles given off in _ minutes
3. Move the lamp 10cm further back
4. Leave the pondweed for 5 minutes to reach the new light intensity
5. Count the number of bubbles given off in 1 minute
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6. Repeat by moving the lamp away by __cm intervals until __cm is reached
7. Repeat so ____ sets of data have been collected and calculate _____ for different light intensities
6. Repeat by moving the lamp away by 10cm intervals until 50cm is reached
7. Repeat so three sets of data have been collected and calculate means for different light intensities
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What are two risks and hazards?
Care with glassware
Light source can get hot
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CVs: ____ and _____ of pondweed, ______ of water, _________
DV: number of bubbles of ______ given off in 1 minute
IV: _______ from light source from pondweed (10-50cm)
CVs: species and size of pondweed, volume of water, temperature
DV: number of bubbles of oxygen given off in 1 minute
IV: distance from light source from pondweed (10-50cm)
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How should the data be analysed?
Collect results in table
Circle anomalies
Calculate means excluding anomalies
Graph
Draw conclusion against hypothesis
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Hypothesis:
As the temperature is increased, the rate of diffusion of the food coloring in the skittle will _______
As the temperature is increased, the rate of diffusion of the food coloring in the skittle will increase (use scientific reasoning in exam)
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What equipment is needed?
The bottom half of a petri dish
Dark-coloured skittles
Water at different temperatures
Thermometers
Graph paper
Heat proof mat
Waste beaker
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Procedure:
1. Place the petri dish on the heatproof mat and graph paper, draw an _ in the middle of paper
2. Pour __mm3 in petri dish, allow it to become still
3. Measure temperature using _________
1. Place the petri dish on the heatproof mat and graph paper, draw an X in the middle of paper
2. Pour 20mm3 in petri dish, allow it to become still
3. Measure temperature using thermometer
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4. Place skittle in centre of petri dish, put it on top of the X on the paper, start the __________
5. Measure how far in cm3 the colour spreads every __s over _ minutes
6. Repeat at 20C-50C, calculate _____ for each
4. Place skittle in centre of petri dish, put it on top of the X on the paper, start the stopwatch
5. Measure how far in cm3 the colour spreads every 10s over 5 minutes
6. Repeat at 20-50C, calculate mean for each
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What is one hazard?
Boiling water
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CVs: _____ ____ of skittles, ______ of water
DV: Rate of ______ of the food colouring in 5 minutes
IV: ________ (20-50C)
CVs: surface area of skittles, volume of water
DV: Rate of diffusion of food colouring in 5 minutes
IV: temperature (20-50C)
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Hypothesis:
The ______ the SA:vol of agar jelly, the faster the rate of diffusion of phenolphthalein (faster it will turn colourless)
The bigger the SA:vol of agar jelly, the faster the rate of diffusion of phenolphthalein (faster it will turn colourless)
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What equipment is needed?
Agar jelly blocks
Hydrochloric acid
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Procedure:
1. Two phenolphthalein blocks provided, keep cutting one in half until ended with _ blocks in total
2. Place blocks one at a time into _________ acid, time how long it takes to turn from ____ to colourless
1. Two phenolphthalein blocks provided, keep cutting one in half until 6 blocks in total
2. Place blocks one at a time into hydrochloric acid, time how long it takes to turn from pink to colourless
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3. Calculate __:___ of each block to use in the analysis of results
3. Calculate SA:Vol of each block to use in the analysis of the results
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What is one hazard?
Hydrochloric acid can cause irritation to skin and burn eyes
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IV: __:___ of agar jelly phenolphthalein block
DV: rate of diffusion, time taken for block to turn ________
CVs: volume of _________ acid
IV: SA:Vol of agar jelly phenolphthalein block
DV: Rate of diffusion, time taken for block to turn colourless
CVs: volume of hydrochloric acid
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Hypothesis:
Starch will break down _______ at a faster rate at optimum pH (_)
Starch will break down amylase at a faster rate at optimum pH (7)
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What equipment is needed?
Spotting tile, test tubes, 3 syringes, pipette, stopwatch, buffer solutions pH 2-7, iodine solution 0.01M, starch solution 0.2%, amylase solution 1%
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Procedure:
1. Add a drop of ______ to each well in spotting tile
2. use syringe to place _cm3 amylase into test tube
3. add _cm3 pH2 buffer to same test tube
1. add a drop of iodine to each well in spotting tile
2. use syringe to place 2cm3 amylase into test tube
3. add 1cm3 pH 2 buffer to same test tube
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4. Add _cm3 starch to amylase and buffer, start stopwatch, mix with a _______
5. every __s transfer a drop of iodine to a new well
6. repeat every __s until iodine stops turning blue/black
4. add 2cm3 starch to amylase and buffer, start stopwatch, mix with a pipette
5. every 10s transfer a drop of iodine to a new well
6. repeat every 10s until iodine stops turning blue/black
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7. record ____ taken for reaction to be completed in a table
8. repeat investigation with pH _-_
7. record time taken for reaction to be completed in a table
8. repeat investigation with pH 3-7
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No hazards
No hazards
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IV: pH _-_
DV: rate ______ breaks down starch
CVs: ________, __________
IV: pH 2-7
DV: rate amylase breaks down starch
CVs: temperature, enzyme and substrate concentration
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Similar experiment as temperature on the breakdown of starch, but use water baths from __-__C and place starch in them for _ minutes
Similar experiment as temperature on the breakdown of starch, but use water baths from 30-60C and place starch in them for 5 minutes
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Hypothesis:
As enzyme (_______) concentration increases, the rate of reaction (break down of _____ _________) increases.
As enzyme (catalase) concentration increases, the rate of reaction (breakdown of hydrogen peroxide) increases.
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What equipment is needed?
(draw this out in exam)
boiling tubes, x3 10ml syringes, specimen tubes, bung and tubing, trough and water, clamp and retort stand, distilled water, 100ml measuring cylinder, stopwatch, permanent marker, 10% yeast, 15vol hydrogen peroxide
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Procedure:
1. Set up equipment as shown in diagram, clamp measuring _______ upside down with a clamp
2. Make a dilution series of __% yeast suspension, the total volume of each specimen tube should be __cm3
1. Set up equipment as shown in diagram, clamp measuring cylinder upside down with a clamp
2. Make a dilution series of 10% yeast suspension, the total volume of each specimen tube should be 10cm3.
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3. Place _cm3 hydrogen peroxide in first boiling tube
4. Add _cm3 yeast and quickly place ____ on boiling tube
5. Every __s mark on measuring cylinder the volume of gas collected
3. Place 6cm3 hydrogen peroxide in first boiling tube
4. Add 3cm3 yeast and quickly place bung on boiling tube
5. Every 10s mark on measuring cylinder the volume of gas collected
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6. Record volume of ___ in results table
7. Repeat stages _,_,_ with other yeast concentrations using clean equipment
6. Record volume of gas in results table
7. Repeat stages 3,4,5 with other yeast concentrations using clean equipment.
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What are two hazards?
Hydrogen peroxide can harm eyes and skin
Glassware smashing
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IV: enzyme (catalase) concentration _,_,_,_,_%
DV: ______ gas produced cm3
CVs: _______ ________ concentration (6cm3), _________
IV: enzyme (catalase) concentration 2,4,6,8,10%
DV: oxygen gas produced cm3
CVs: hydrogen peroxide concentration (6cm3), temperature
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Hypothesis:
As the enzyme concentration (_______) increases, the rate of ______ break down increases
As the enzyme concentration (trypsin) increases, the rate of casein break down increases
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What equipment is needed?
Reconstituted milk power 2%, trypsin 1%, pipettes, boiling tubes and rack, distilled water, x2 10cm3 syringes, colorimeter, cuvettes, cuvette rack
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Procedure:
1. Dilute 1% trypsin to _._-_._%
2. Place _cm3 trypsin and water into cuvette, set absorbance to zero
3. Add _cm3 milk to second cuvette
1. Dilute 1% trypsin to 0.2-1.0%
2. Place 2cm3 trypsin and water into cuvette, set absorbance to zero
3. Add 2cm3 milk to second cuvette
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4. Add _cm3 trypsin to milk, mix, place in __________, start stopwatch, use ___nm
5. Measure absorbance immediately and then at __s intervals for 5 mins
6. Rinse cuvette with distilled water and repeat with each _____ concentration
4. Add 2cm3 trypsin to milk, mix, place in colorimeter, start stopwatch, use 525nm
5. Measure absorbance immediately and then at 15s intervals for 5 mins
6. Rinse cuvette with distilled water and repeat with each trypsin concentration
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No hazards
No hazards
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IV: trypsin concentration (_._-_._%)
DV: breakdown of ______ by measuring absorbance
CVs: __________, volume of ______
IV: trypsin concentration (0.2-1.0%)
DV: breakdown of casein by measuring light absorbance
CVs: temperature, volume of casein
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## Other cards in this set

### Card 2

#### Front

What equipment is needed?

#### Back

Pond weed, boiling tube, water, lamp, ruler, timer, heat shield (justify the use of this equipment in the exam)

### Card 3

#### Front

Procedure:
1. Leave the pondweed for _ minutes to reach the new light intensity
2. Count the number of bubbles given off in _ minutes

### Card 4

#### Front

3. Move the lamp __cm further back
4. Leave the pondweed for _ minutes to reach the new light intensity
5. Count number of bubbles given off in _ minutes

### Card 5

#### Front

6. Repeat by moving the lamp away by __cm intervals until __cm is reached
7. Repeat so ____ sets of data have been collected and calculate _____ for different light intensities