Page 1 of 137
IGCSE Biology - Study Guide Combined BUNDLE ( Latest
2025)
What does an animal cell consist of? .....ANSWER.....Cell
membrane, cytoplasm, mitochondria, nucleus
What does a plant cell consist of? .....ANSWER.....Permanent
vacuole, cell membrane, cell wall, mitochondria, chloroplasts
which are full of chlorophyll, cytoplasm, nucleus
What is their role of the nucleus? .....ANSWER.....Controls the
activity of the cells
What is the role of the cell membrane? .....ANSWER.....Selectively
permeable membrane which controls the substances passing in
and out of the cell
What is the role of mitochondria? .....ANSWER.....Carry out some
of the reactions of respiration to release energy that the cell can
use
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What is the role of cytoplasm? .....ANSWER.....Complex material
made of many different structures where all the chemical
reactions take place
What is the role of the cell wall? .....ANSWER.....Made of
carbohydrate called cellulose which is a tough material that
helps the cell keep its shape,it is freely permeable
What is the role of chloroplasts? .....ANSWER.....These contain
chlorophyll and are green. The chloroplasts absorb light energy
to make food in the process of photosynthesis
What is the role of the vacuole? .....ANSWER.....This is a
permanent feature of the cell and is filled with cell sap which is a
store of dissolved sugars, mineral ions and other solutes
What is a catalyst and state the link between a catalyst and
enzyme .....ANSWER.....An enzyme is a biological catalyst which
means that it speeds up a reaction without being used up itself
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How are the activities of a cell controlled? .....ANSWER.....The
nucleus contains genes, which control the production of enzymes,
which catalyst reactions in the cytoplasm
What is a metabolic reaction? .....ANSWER.....A chemical reaction
taken place inside a cell
Describe th process of enzyme 'lock and key' action
.....ANSWER.....1. The substrate enters the enzymes active site as
it's active site is complimentary to the enzymes forming an
enzyme substrate complex
2. The reaction takes place and products are formed which leave
the active site
Name one factor which affects enzymes
.....ANSWER.....Temperature: in the human body work best at
37C which is their optimum temperature. After this point the
enzymes departure as the active site changes shape. Before this
point, as the temperature rises, so does the rate of reaction as it
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will give the molecules of molecules of enzyme and substrate
more energy, so they will collide more frequently
Describe an investigation which shows the effect of temperature
on enzymes .....ANSWER.....Starch and amylase:
C--> change the temperature of each solution of amylase and
starch
O--> Use the same amount of starch and amylase in each
solution and keep them in the water baths for the same amount
of time
R--> Repeat the tests for each temperature
M-->Use iodine to test for starch once you've placed the solution
on a spotting tile. Time in minutes and when iodine has changed
colour from black/brown- yellow no more starch is present
IGCSE Biology - Study Guide Combined BUNDLE ( Latest
2025)
What does an animal cell consist of? .....ANSWER.....Cell
membrane, cytoplasm, mitochondria, nucleus
What does a plant cell consist of? .....ANSWER.....Permanent
vacuole, cell membrane, cell wall, mitochondria, chloroplasts
which are full of chlorophyll, cytoplasm, nucleus
What is their role of the nucleus? .....ANSWER.....Controls the
activity of the cells
What is the role of the cell membrane? .....ANSWER.....Selectively
permeable membrane which controls the substances passing in
and out of the cell
What is the role of mitochondria? .....ANSWER.....Carry out some
of the reactions of respiration to release energy that the cell can
use
,Page 2 of 137
What is the role of cytoplasm? .....ANSWER.....Complex material
made of many different structures where all the chemical
reactions take place
What is the role of the cell wall? .....ANSWER.....Made of
carbohydrate called cellulose which is a tough material that
helps the cell keep its shape,it is freely permeable
What is the role of chloroplasts? .....ANSWER.....These contain
chlorophyll and are green. The chloroplasts absorb light energy
to make food in the process of photosynthesis
What is the role of the vacuole? .....ANSWER.....This is a
permanent feature of the cell and is filled with cell sap which is a
store of dissolved sugars, mineral ions and other solutes
What is a catalyst and state the link between a catalyst and
enzyme .....ANSWER.....An enzyme is a biological catalyst which
means that it speeds up a reaction without being used up itself
,Page 3 of 137
How are the activities of a cell controlled? .....ANSWER.....The
nucleus contains genes, which control the production of enzymes,
which catalyst reactions in the cytoplasm
What is a metabolic reaction? .....ANSWER.....A chemical reaction
taken place inside a cell
Describe th process of enzyme 'lock and key' action
.....ANSWER.....1. The substrate enters the enzymes active site as
it's active site is complimentary to the enzymes forming an
enzyme substrate complex
2. The reaction takes place and products are formed which leave
the active site
Name one factor which affects enzymes
.....ANSWER.....Temperature: in the human body work best at
37C which is their optimum temperature. After this point the
enzymes departure as the active site changes shape. Before this
point, as the temperature rises, so does the rate of reaction as it
, Page 4 of 137
will give the molecules of molecules of enzyme and substrate
more energy, so they will collide more frequently
Describe an investigation which shows the effect of temperature
on enzymes .....ANSWER.....Starch and amylase:
C--> change the temperature of each solution of amylase and
starch
O--> Use the same amount of starch and amylase in each
solution and keep them in the water baths for the same amount
of time
R--> Repeat the tests for each temperature
M-->Use iodine to test for starch once you've placed the solution
on a spotting tile. Time in minutes and when iodine has changed
colour from black/brown- yellow no more starch is present
