AQA GCSE Biology paper 1
Magnification equation
Magnification= image size/actual object size
Light microscope- how many um in 1 mm
1000 um
Light microscope- how many nm in 1 um
1000 nm
Light microscope- why can we see the nucleus and cell wall but not the
mitochondria
Too small and not stained
Light microscope- how can we see smaller parts of cells
An electron microscope has much more resolution and magnification
,What is osmosis?
The movement of water from an area with high concentration of water to an area of
low concentration of water
What's a solute
Something that dissolves in water
Investigating osmosis- what are the results
High concentration of sugar in solution- water moves out of potato cells into the
solution. potato gets smaller, low concentration potato gets bigger
Control variables of investigating osmosis
Amount of solution
Investigating osmosis- why should you remove excess water with paper towels
before weighing
to ensure that any change in the mass of the potato is due to a change in the water
content inside the potato cells
, How do you test for starch
Add iodine to substance. Turns black if starch present
How to test for protein
Add biuret. Turns purple
How to test for reducing sugar
Add benedicts and heat for 2 mins. Turns red
How to test for lipid
Add ethanol then add water. Turns cloudy
Investigating amylase enzyme- why do you need a water bath
To maintain the correct temperature, because temperature affects reaction rate
Investigating amylase enzyme- if you text at ph 3,4,5,6,7,8,9&10 why don't we
know the exact optimum ph
Magnification equation
Magnification= image size/actual object size
Light microscope- how many um in 1 mm
1000 um
Light microscope- how many nm in 1 um
1000 nm
Light microscope- why can we see the nucleus and cell wall but not the
mitochondria
Too small and not stained
Light microscope- how can we see smaller parts of cells
An electron microscope has much more resolution and magnification
,What is osmosis?
The movement of water from an area with high concentration of water to an area of
low concentration of water
What's a solute
Something that dissolves in water
Investigating osmosis- what are the results
High concentration of sugar in solution- water moves out of potato cells into the
solution. potato gets smaller, low concentration potato gets bigger
Control variables of investigating osmosis
Amount of solution
Investigating osmosis- why should you remove excess water with paper towels
before weighing
to ensure that any change in the mass of the potato is due to a change in the water
content inside the potato cells
, How do you test for starch
Add iodine to substance. Turns black if starch present
How to test for protein
Add biuret. Turns purple
How to test for reducing sugar
Add benedicts and heat for 2 mins. Turns red
How to test for lipid
Add ethanol then add water. Turns cloudy
Investigating amylase enzyme- why do you need a water bath
To maintain the correct temperature, because temperature affects reaction rate
Investigating amylase enzyme- if you text at ph 3,4,5,6,7,8,9&10 why don't we
know the exact optimum ph
