// Topic 1 PART 1 Flashcards
potato chips placed in distilled water for 20 minutes. figure 7 shows mass increase in each chip
explain why potato chip B has a greater increase in mass than potato chip A
chip B has a greater surface area therefore more water absorbed
potato chip A is transferred from the distilled water into a concentrated salt solution.
explain what will happen to the cells in potato chip A
cells lose water as it moves out by osmosis from a high concentration of water molecules in the potato to a low concentration of water molecules in the solution
the potatoes of a potato plant develop deep underground.
explain one difference in the sub-cellular structures in a cell in the potato and those in a cell in the leaf of the potato plant
no chloroplasts in the potato as there is no light for photosynthesis
describe the test to identify starch
add iodine solution and if it turns black or blue then starch is present
figure 8 shows a calorimeter
explain why the calorimeter has a lid
it reduces heat loss so energy from sugar is used to heat water
figure 8 shows a calorimeter
state why it is important to stir the water in the calorimeter
ensures heat is distributed evenly throughout the water
explain how the magnification of 400X can be obtained using the lenses on a light microscope
select the 40X objective lens combined with a 10X eye piece lens
potato cells contain the enzyme catalase. this catalysed the breakdown of hydrogen peroxide into oxygen and water. figure 15 shows what happened when a student placed a potato disc in a 5% hydrogen peroxide solution
which term describes the hydrogen peroxide in this reaction?
A) product
B) substrate
C) active site
D) control
B) substrate
potato cells contain the enzyme catalase. this catalysed the breakdown of hydrogen peroxide into oxygen and water. figure 15 shows what happened when a student placed a potato disc in a 5% hydrogen peroxide solution
the potato discs all had the same mass
explain why the student used potato discs with the same mass
mass is a variable so results can be compared
potato cells contain the enzyme catalase. this catalysed the breakdown of hydrogen peroxide into oxygen and water. figure 15 shows what happened when a student placed a potato disc in a 5% hydrogen peroxide solution
state two other factors that need to be kept the same to improve this investigation
temperature and pH
potato cells contain the enzyme catalase. this catalysed the breakdown of hydrogen peroxide into oxygen and water. figure 15 shows what happened when a student placed a potato disc in a 5% hydrogen peroxide solution. figure 16 shows results
state and explain a conclusion based on these results
increasing the concentration of hydrogen peroxide decreases the time taken for the disc to rise. it provides more substrate and more active sites are occupied so oxygen is released faster
the student decided that the rate for the 25% hydrogen peroxide solution wasn’t anomalous
give the reason why the result wasn’t anomalous
substrate isn’t the rate limiting factor
student had four different foods labelled W, X, Y, and Z each tested for starch and protein. colours shown in figure 1.
which solution contains starch but not protein?
A) solution W
B) solution X
C) solution Y
D) solution Z
C) solution Y
describe how a solution of food can be tested for reducing sugars
add benedicts solution and heat. if present the solution turns brick red
describe how this calorimeter can be used to find the energy content of 10g of food
measure the start and end temperature of the water and burn food in chamber. use the increase in temperature of water to calculate the energy content
