Regents Review: Photosynthesis and Respiration by pZlI4A64


									                         Regents Review: Photosynthesis and Respiration

Define the following terms: SEE YOUR GLOSSARY IN YOUR REVIEW BOOK
        ATP –

        Cellular Respiration –

        Chloroplast –

        Gas Exchange –

        Glucose –

        Guard Cells –

        Homeostasis –

        Mitochondria –

        Photosynthesis –

        Respiration –

What are the basic needs for plant growth?
Carbon Dioxide (CO2), Water (H20), Light

Photosynthesis is the conversion of light energy into chemical energy

What is the difference between autotrophic nutrition and heterotrophic nutrition?
Autotrophs can make their own food (energy)
Heterotrophs need to eat food to obtain energy

What are the two types of autotrophs?
Photoautotrophs - use light energy to make food (ex. Green plants, algae)
Chemoautotrophs - use inorganic chemicals to make food (Ex. mostly bacteria)

What are the photosynthetic pigments? Which is the most abundant?
Chlorophyll a & b (green) – most abundant
Carotenes (orange)
Xanthophylls (yellow)
What process is associated with a chloroplast? What is a chloroplast made of?
Photosynthesis. Contains: photosynthetic membranes arranged in flattened sacs called thylakoids,
stacks of thylakoids are called grana, regions between the grana are known as stroma

Why cant we just use chlorophyll alone to produce glucose? What else do we need?
It only absorbs certain amounts of light energy so we need multiple pigments. Also, it doesn’t
convert this absorbed energy into chemical energy alone, we need the proteins in the thylakoid

Describe how guard cells regulate homeostasis within the stomates:
Regulate the opening and closing of stomates (caused by osmosis with in the two guard cells).
They are closed when little water is available, at low temperatures or when little light available
and will open when the leaf needs to release extra water, at high temperatures or when there is
enough light available.

What is the overall chemical formula for photosynthesis?

                6 CO2 + 12 H2O  C6H12O6 + 6 O2 + 6 H2O

        Carbon dioxide + water + light  Glucose + oxygen + water
Label the layers of a leaf cross-section below? What does each layer do/contain?

1. Outermost layer is a clear waxy cuticle that protects inner tissues and slows down water loss
from leaf
2. Epidermis is below cuticle, contains no pigment, protects inner tissues, contains stomates
(small openings on the underside of the leaf that allow the exchange of carbon dioxide, oxygen
and water vapor between the leaf and the environment)
3. Palisade mesophyll is a tightly packed 1-2 cell thick layer filled with chloroplasts, site of
4. Spongy mesophyll has irregularly shaped cells and large air spaces in between cells (stomates
located near this layer to allow for gas exchange) with fewer chloroplasts found here
5. Vein contains xylem (to transport water/mineral) and phloem (to transport food/materials)

What is the difference between the light and dark
Light dependent reactions produce ATP that the light-
independent reactions use to make glucose

What is Chemiosmosis?
Movement of H+ ions through ATP synthase proteins
within the thylakoid membrane to take ADP + P 
ATP (to produce energy for the cells to use)
Photosynthesis converts inorganic materials (H2O, CO2, light) into organic molecules (C6H12O6)

What factors affect photosynthesis:
Light intensity, temperature, water availability, mineral availability, pH, CO2 availability

What does cellular respiration break down to form energy?
Energy (e-) is released from the breakdown of glucose and used to combine ADP + P to form

Where do organisms obtain the raw materials needed?
From the food they digest (heterotrophs) or create themselves (autotrophs)

Does it occur in autotrophs and heterotrophs?
Yes in both

What organelle is associated with cellular respiration?

What process transfers energy from one molecule to another?
Electron transport chain

Is the high-energy molecule ATP or ADP?

What are the two types of cellular respiration? Anaerobic and aerobic respiration. Which requires
oxygen? Aerobic. Which produces the most energy by the complete breakdown of glucose?

What is glucose broken down into?
Two pyruvic acids

Describe the process of glycolysis? Does it occur in both types of respiration? How much energy
is produced?
Splitting of glucose (6-carbons) into two pyruvic acid molecules (3-carbons) which occurs in the
cytoplasm. Occurs in both types and produces 4 ATP total for each glucose molecule.
Describe fermentation and what are the end products of fermentation in yeast and bacteria?
Pyruvic acid is changed into other compounds. In yeast it makes ethyl alcohol and carbon
dioxide. In bacteria it makes lactic acid.

Where does pyruvic acid breakdown?
Within the mitochondria on the surface of the inside membrane

What is the net overall output for each glucose molecule in the Kreb’s cycle?
For each glucose molecule, it takes two turns of the Kreb’s cycle, producing 1 ATP for each cycle
producing a total of 2 ATP for each glucose molecule

How many ATP molecules does the electron transport chain produce? Where does this occur?
Produces 32 ATP for each glucose molecule. Occurs within the mitochondria across the inner

What is the overall net reaction of cellular respiration?
                      C6H12O6 + 6 H2O + 6 O2  6 CO2 + 12 H2O + 36 ATP
                Glucose + Water + Oxygen  Carbon Dioxide + Water + Energy

Why does muscle fatigue happen in our bodies?
During prolonged periods of physical activity, the muscle cells use oxygen faster than it can be
supplied (shuts down Krebs cycle). Muscles then continue to release energy by glycolysis.
Pyruvic acid is converted to lactic acid which can build up causing muscle fatigue

Can other organic molecules be used, like proteins or fats? Yes

                                     Regents Review Questions
1. All life depends on the availability of
usable energy. This energy is released when
                                                       2. The rate at which all organisms obtain,
(1) organisms convert solar energy into the
                                                       transform, and transport materials depends
   chemical energy found in food
                                                       on an immediate supply of
                                                       (1) ATP and enzymes
(2) respiration occurs in the cells of
                                                       (2) solar energy and carbon dioxide
   producers and high-energy molecules
                                                       (3) carbon dioxide and enzymes
   enter the atmosphere
                                                       (4) ATP and solar energy
(3) cells carry out the process of
(4) animal cells synthesize starch and
   carbon dioxide
3. A five-year study was carried out on a       6. The graph below shows photosynthetic
population of algae in a lake. The study        activity in an ecosystem over a 24-hour
found that the algae population was steadily    period.
decreasing in size. Over the five-year period
this decrease most likely led to
(1) a decrease in the amount of nitrogen
    released into the atmosphere
(2) an increase in the amount of oxygen
    present in the lake
(3) an increase in the amount of water
    vapor present in the atmosphere
(4) a decrease in the amount of oxygen
    released into the lake                      Data for a study on respiration in this
                                                ecosystem should be collected during
                                                (1) interval A, from only the producers in
                                                   the ecosystem
4. The diagram below represents a               (2) intervals A and B, from only the
biological process.                                consumers in the ecosystem
                                                (3) intervals A and B, from both the
                                                   producers and consumers in the
                                                (4) interval A only, from abiotic but not
Which set of molecules is best represented         biotic components of the ecosystem
by letters A and B?
(1) A: oxygen and water
   B: glucose                                   7. A student studied the location of single-
(2) A: glucose                                  celled photosynthetic organisms in a lake for
   B: carbon dioxide and water                  a period of several weeks. The depth at
(3) A: carbon dioxide and water                 which these organisms were found at
   B: glucose                                   different times of the day varied greatly.
(4) A: glucose                                  Some of the data collected are shown in the
   B: oxygen and water                          table below.

5. The diagram below represents a cross
section of part of a leaf.

                                                A valid inference based on these data is that
                                                (1) most photosynthetic organisms live
                                                   below a depth of 150 centimeters
                                                (2) oxygen production increases as
Which life functions are directly regulated        photosynthetic organisms move deeper in
through feedback mechanisms associated             the lake
with the actions of the structures labeled X?   (3) photosynthetic organisms respond to
(1) excretion and immunity                         changing light levels
(2) digestion and coordination                  (4) photosynthetic organisms move up and
(3) circulation and reproduction                   down to increase their rate of carbon
(4) respiration and photosynthesis                 dioxide production
8. The relative amount of oxygen in the atmosphere of Earth over millions of years is shown in
   the graph below.

   At what point in the history of Earth did autotrophs most likely first appear?
       (1) 3500 million years ago         (3) 1500 million years ago
       (2) 2500 million years ago         (4) 500 million years ago

    Untreated organic wastes were accidentally discharged into a river from a sewage treatment
plant. The graph below shows the dissolved oxygen content of water samples taken from the river
at specific distances downstream from the plant, both before, and then three days after the
discharge occurred.

9. Explain why an energy-releasing process occurring in the mitochondria of the decomposer
   organisms is most likely responsible for the change indicated by the data shown at
   sampling site C in the graph.

At site C oxygen is being used by the mitochondria of the decomposer to break down glucose
molecules to form ATP (energy) by the process of cellular respiration to use for the organisms
various life processes.

   In recent years, the striped bass population in Chesapeake Bay has been decreasing. This is
due, in part, to events known as “fish kills,” a large die-off of fish. Fish kills occur when oxygen-
consuming processes in the aquatic ecosystem require more oxygen than the plants in the
ecosystem produce, thereby reducing the amount of dissolved oxygen available to the fish. One
proposed explanation for the increased fish kills in recent years is that human activities have
increased the amount of sediment suspended in the water of Chesapeake Bay, largely due to
increased erosion into its tributary streams. The sediment acts as a filter for sunlight, which
causes a decrease in the intensity of the sunlight that reaches the aquatic plants in the Chesapeake
Bay ecosystem.

10. Identify the process carried out by organisms that uses oxygen and contributes to the fish

Cellular Respiration

11. State how a decrease in the amount of light may be responsible for fish kills in the
    Chesapeake Bay area.

The decrease in the amount of light will limit the resources the plants need to convert
carbon dioxide, water and light into glucose and oxygen which is used by the fish and
other oxygen-consuming organisms within the bay. A decrease in light will limit the
production of oxygen being released through photosynthesis of the bay’s plants.

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