C H A P T E R
Chapter Expectations
Briefly explain each of the following points.
• Metabolism involves the use of chemical
energy. (3.1)
• Through a series of reactions,
photosynthesis transfers the energy in light
to energy in chemical bonds. (3.2)
• The chemical energy stored through
photosynthesis is transferred to a form
usable anywhere in the cell during cellular
respiration. (3.2)
• All eukaryotic and most prokaryotic cells
use glycolysis to form ATP. (3.3)
• Aerobic respiration efficiently produces 36
or 38 molecules of ATP from one molecule
of glucose, but it requires that a cell have
access to oxygen. (3.3)
• Anaerobic respiration quickly forms two
molecules of ATP per molecule of glucose,
but produces toxic waste products. (3.3)
• The structure of chloroplasts and
mitochondria provides evidence that these
organelles may once have been free-living
micro-organisms. (3.4)
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R E V I E W
• Research into cellular biology has led to
practical applications. (3.4)
• Some industries harness the ability of
bacteria to metabolize organic materials
toxic to most organisms. (3.4)
Language of Biology
Write a sentence using each of the following words or
terms. Use any six terms in a concept map to show
your understanding of how they are related.
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energy
potential energy
kinetic energy
chemical energy
metabolism
wave model of light
electromagnetic
spectrum
photon model of light
photons
pigments
chlorophyll
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photosystems
reaction centre
ATP
Calvin cycle
cellular respiration
aerobic
glycolysis
fermentation
oxygen debt
anaerobic
bioremediation
radioactive
UNDE RSTAN DIN G CON CEPTS
1. What is the source of energy in your body?
2. Explain the terms “potential energy” and
“kinetic energy” with respect to a cell.
3. (a) How do your muscle cells use energy?
(b) Describe conditions where muscles use an
alternative process.
(c) Explain one possible reason that muscle
cells are the best cells to switch to the
alternative process.
4. Describe three metabolic processes in your
body powered by energy in your food.
7. Write the simple reaction for photosynthesis.
(a) Which molecule listed has the highest
potential energy? Justify your response.
(b) Which molecule has the lowest potential
energy? Justify your response.
8. Describe the features of light energy that are
important to the process of photosynthesis.
9. Identify one pigment used by a chloroplast to
help with photosynthesis.
10. What colour or colours of light are absorbed by
a green leaf? Explain your response.
5. “Energy is used to keep the cell organized.”
(a) What does this statement mean?
(b) What would happen to a cell that has no
energy?
6. Refer to Chapter 1 to find the structural
formula of glucose. Glucose is made of carbon,
oxygen and hydrogen atoms. Identify the
source of each type of atom in the process of
photosynthesis.
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11. Where in the chloroplast are the photosystems
found? Draw a diagram and indicate the
location of the photosystems.
12. Briefly describe the role played by each
photosystem in the chloroplast.
15. What is the role of cellular respiration in your
cells?
16. Draw a diagram of a cell and show where each
stage of cellular respiration takes place.
17. How is oxygen important to cellular respiration?
13. Where do the synthesis reactions of
photosynthesis take place?
18. Identify three different organisms that use
fermentation regularly.
14. (a) List the three stages of photosynthesis.
(b) Identify how the energy captured in one step
is used to power changes in another step.
19. How are radioactive molecules used to study
metabolic processes?
IN QU IRY
β-gal (µg)
20. Lactose is a sugar that most bacteria can use as
a source of glucose. They can do so because
they manufacture an enzyme called
betagalactosidase (β-gal). This enzyme will
break down a molecule of lactose into a
molecule of glucose and a molecule of
galactose. In an experiment, bacteria were
supplied with lactose, and the amount of β-gal
was monitored. The results are illustrated in
the graph below.
(a) What can be interpreted from the graph?
(b) Why would it be incorrect to conclude from
these results that lactose is acting directly
on the transcription of mRNA to produce
the β-gal protein?
(c) Sketch a graph that would illustrate the
relationship between cytoplasmic glucose
and β-gal levels after the addition of lactose.
21. Dinitrophenol (DNP) is a chemical that
interferes with the production of ATP in both
chloroplasts and mitochondria. In an attempt
to identify the minimal concentration of DNP
required to inhibit ATP production, DNP was
applied to separate suspensions of both
organelles. Data are presented in the table.
(a) Which set of data would represent the
chloroplast?
(b) Which organelle would be considered the
most active? Explain.
(c) Which organelle is most susceptible to
changing concentrations of DNP? Explain.
Concentration of DNP
Organelle
5%
15%
25%
35%
Volume of CO2
released (mL)
0.50
0.11
0.05
0.01
Volume of O2
released (mL)
0.88
0.04
0.01
n/a
22. Glycolysis takes place in the cytoplasm of
eukaryotic cells. This indicates that the process
is very ancient, probably older than the
development of eukaryotic cells. Explain briefly.
Lactose
added
23. In single-celled organisms, compare the
relative need for kinetic energy in a plant-like
cell and an animal-like cell.
total bacterial protein (µg)
COMMU N ICATIN G
24. On Earth, matter cycles and energy flows.
(a) To make this statement clearer, explain how
matter is different from energy.
(b) Draw a diagram to illustrate the given
statement.
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MHR • Cellular Functions
25. Make a concept map or flowchart that shows
what happens to a glucose molecule from the
time it enters a plant or animal cell.
26. Make a diagram showing how photosynthesis
and aerobic respiration form a cycle of
connected reactions.
29. A train has derailed 13 km from your home.
Some toxic chemicals spilled onto the ground.
Develop a bioremediation plan to share with
your town council. Who could you contact for
support and help?
30. Energy profiles for photosynthesis and cellular
respiration are illustrated above.
(a) With reasons to support your choices,
identify which energy profile is for cellular
respiration and which is for photosynthesis.
(b) Compare the energy required to make
glucose to the amount of energy required to
break it down.
B
Potential Energy (kJ)
28. Refer to Chapter 2 for information about the
chloroplast and the mitochondrion.
(a) Draw a diagram of a chloroplast. Label your
diagram to show the outer membrane,
thylakoids, grana, stroma and lamellae.
(b) Draw a diagram of a mitochondrion. Label
your diagram to show the outer membrane,
inner membrane, cristae and matrix.
(c) Compare these two structures. Make a chart
to record how the structures are similar and
how they are different.
A
Potential Energy (kJ)
27. Review the process of phagocytosis from
Chapter 1. Describe the structure of the vesicle
formed. Compare this to the outer membrane of
both the chloroplast and the mitochondrion.
Time
Time
31. Living cells capture a tiny amount of the solar
radiation available. This tiny amount supports
almost all the life on earth.
(a) What would be the consequence if twice as
much energy were captured? Explain.
(b) What would be the consequence if half as
much energy were captured? Explain.
32. Eukaryotic cells have mitochondria for aerobic
respiration. Some eukaryotic cells have
chloroplasts to capture solar energy in food
molecules. Indicate whether you agree or
disagree with the following statements:
(a) The first cells with chloroplasts were
predators. Explain briefly.
(b) Cells with chloroplasts are still predators.
Explain briefly.
(c) Perhaps the biggest physical difference
between a plant cell and an animal cell is
the presence of a cell wall. Explain briefly.
M A KIN G CON N ECTION S
33. Despite many attempts, researchers have been
unable to get photosynthesis to proceed outside
a chloroplast. Why are researchers still
interested in pursuing this goal? What
possible practical use could come from
attaining the goal?
34. People have made use of fermentation for
thousands of years.
(a) Identify two ancient uses for this cellular
process.
(b) Identify one modern use for this cellular
process.
These people wanted to learn more about the
biological processes in their industry.
(a) Today, pasteurization is used in the milk
industry, but not in the wine industry.
Explain briefly.
(b) Explain the relationship between the
reproducing yeast cells shown here and the
process of fermentation.
35. People now turn to bacteria for biological
solutions of technological problems. Explain
this using one example from the text.
36. In Chapter 1, you learned about the
experiments conducted by Louis Pasteur to
explain how micro-organisms can spoil a broth.
This research was funded by the wine industry.
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