Download Chapter 7 Test Review Cells are Busy Places!

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Chapter 7 Test Review
Cells are Busy Places!
Major Concepts and Key Ideas:
1) Photosynthesis occurs in chloroplasts and converts light energy into chemical energy.
Key Ideas:
Plants and animals require energy to function.
Plants exchange gases with the atmosphere.
Plants use light energy, carbon dioxide and water to make sugars.
Sugars produced during photosynthesis are used for maintenance and growth.
2) Cellular respiration provides the energy for cells to function.
Key Ideas:
Cellular respiration occurs in the cells of ALL living things.
Cellular respiration converts glucose into ATP, the form of energy used by cells.
3) The sun provides the energy for almost all living systems on Earth.
Key ideas:
Photosynthesis connects the sun to the energy needs of all organisms, including animals.
Biosynthesis and breakdown reactions provide the energy and matter needed by organisms.
Photosynthesis and cellular respiration explain where most organisms get the matter and
energy they need to survive.
4) The connection between Photosynthesis and Cellular Respiration is found in plants and animals.
Key Ideas:
Plants and animals get their energy from chemicals
Different organisms require their chemical energy to come from specific forms
The following questions, IF you study them, should be of great assistance on the
upcoming test!
1. Compare the reactants of the photosynthesis equation to the products of the equation for respiration. (Note:
Use equations shown in Explain 337 Powering Cellular Activities). What do you notice?
6 CO2 + 6 H2O + light
C6H12O6 + 6 O2
C6H12O6 + 6 O2
6 CO2 + 6 H2O + ATP
The reactants of photosynthesis are the products of cellular respiration!
2. Compare the reactants of the respiration equation to the products of the Photosynthesis equation. What do
you notice?
6 CO2 + 6 H2O + light
C6H12O6 + 6 O2
C6H12O6 + 6 O2
6 CO2 + 6 H2O + ATP
The reactants of cellular respiration are the products of photosynthesis!
3. In what organelle does photosynthesis occur? _Chloroplast_ How about cellular respiration?
Cytoplasm/Mitochondria
4. Give at least two reasons why the process of photosynthesis is so important to life on Earth.
1. Cycles CO2 (absorbs from atmosphere) & makes oxygen (O2) gas
2. Converts CO2 and H2O into glucose (C6H12O6) which provides the energy for all living things.
5. Describe how the Light Dependent & Light Independent Reactions of photosynthesis are different in a
plant. What products are produced in each?
Light Dependent (requires light) reactions creates ATP and produces (as waste) O2.
Light Independent (also called the “Calvin-Benson Cycle”) reactions make 3-carbon sugars that can be
synthesized into glucose. (Note: these smaller molecules can also be biosynthesized into amino acids, fatty acids,
etc., the plant needs to survive and grow)
6. What pigment is crucial for absorbing light and thus allowing photosynthesis to occur? Where is this pigment
found in a plant cell?
Chlorophyll, which is located in the chloroplast
7. Describe the basic steps of aerobic (= using oxygen) cellular respiration in both plant and animal cells and
where in the cell this process occurs.
(1) GLYCOLYSIS (Cytoplasm)
(2) KREBS CYCLE (Mitochondria)
(3) ELECTRON TRANSPORT (Mitochondria)
8. Which process, aerobic or anaerobic (= without oxygen) produces the most adenosine triphosphate (ATP)?
Aerobic respiration: Produces up to 38 ATP molecules
Anaerobic respiration only produces 2 ATP. Not very much…
9. Draw a four-step food chain showing the type of energy (light, chemical, heat, etc.) at each step. Start with
the SUN!
Chemical: energy is
now stored in protein in
the arm muscle
Heat energy
Heat energy
Light
energy
Chemical energy:
Glucose/Starch
Chemical: energy is stored in
ATP, amino acids/protein &
other organic molecules
Chemical: various
organic molecules
10. Write the complete balanced chemical reaction for Photosynthesis below (See Explain 340 or your journal
notes). Below that, write the complete balanced chemical reaction for Cellular Respiration.
Photosynthesis:
6H2O + 6CO2 (+ light energy)
Cellular Respiration: C6H12O6 + O2
C6H12O6+ 6O2
6H2O + 6CO2 (makes ATP = chemical energy)
11. Which of the above reactions is a BIOSYNTHESIS reaction? __photosynthesis___
12. Which of the above reactions is a DECOMPOSITION reaction? ___cellular respiration____
13. Describe the difference between biosynthesis & decomposition reactions. Use an example (other than the
reactions above) for each.
Biosynthesis is the putting together of molecules, like when glucose is formed into chains making starch (or even
longer chains making cellulose, or amino acids into proteins.
Decomposition is the breaking apart (“breakdown”) of molecules, like when protein is broken down into amino
acids, or glucose is broken down into pyruvate during Glycolysis.
14. Why does it take acres of grass to feed/support a single wildebeest (a large herbivore found in the African
Plains) and a herd of (many) wildebeest to feed a single lion? Use Pictures, Arrows, and words to explain
your answer. Make sure your answer addresses energy transfer at each trophic level.
a. Energy Pyramid
Draw/label each level
Carnivore
10% of chemical
energy
transferred
b. Explain how the drawing at left answers the
question of why it takes a herd of wildebeest to feed
a single lion.
• Need lots of producers (grass) to trap sunlight
Heat
Energy
(90%)
Herbivores
10% of chemical
energy
transferred
Producers
Light Energy
energy and change it into chemical energy
(glucose).
• The grass supports the herbivores
(Wildebeest), but only 10% of original energy
stored in grass gets passed on.
• Energy used for growth,
reproduction, body functions but most is lost
as HEAT
• B/c the Wildebeest use a lot of the
energy they take in, the Lion only gets
1% of the original energy that the plants
had!
• 90% is lost at EACH TROPHIC level!
15.
Give an example of each type of consumer and what type of food they would eat
Herbivore__a plant eater: horse, cow, deer, etc. _____________________
Omnivore__an organism that eats plant and/or meat: Humans, bears
Carnivore_a meat eater : Lion, wolf_______________________________
Autotroph (“self-feeder”)_an oirganism that captures energy from the sun to makes its own food
(glucose): plants, algae, phytoplankton
Chemotroph an organism that gets its energy directly from chemical reactions of inorganic (non-food)
molecules: “Extreme” archaebacteria that live near deep-ocean thermal vents or hot springs that use
hydrogen sulfide for energy
Heterotroph (“other eater”) an organism that gets its energy from the food that it consumes: animals,
insects, fungi)
16. Label the diagram, showing where the CARBON in the chicken leg originally came from: (Where does the
carbon start and how does it get into the drumstick?). In your answer address where CARBON is at in every step
and HOW it got there (think biosynthesis, etc.).
Where does the carbon
start? CO2 in the air
Where is the carbon now?
glucose/starch
How did it get there?
1) Photosynthesis (makes glucose)
2) Biosynthesis of glucose into
starch
Where is the carbon now? In
the protein of the
chicken’s leg muscle
How did it get there?
1) Breakdown of corn/starch into glucose
2) Breakdown of glucose in cell
respiration
3) Biosynthesis of amino acids from the 2
or 3- carbon products of respiration,
4) Biosynthesis of amino acids into protein
needed in leg muscle.