Respiration and Photosynthesis


1. With which process(es) is each of the following associated?
    Glucose is used

    O2 is used

    PGAl is produced

    NAD is used

    FAD is used

    CO2 is used

                                                               Aerobic Respiration        Photosynthesis

             X

             X

             X                                 X

             X

             X

                                                X
2. Where in the cell does each of the following occur? In what organisms (plant/animal) does each occur?
 

Light dependent reactions

Glycolysis

Kreb's Cycle

Light independent reactions
 

Part of Cell Type of Organism

Grana of chloroplast Plant

Cytoplasm Plant and Animal

Matrix of mitochondria Plant and Animal

Stroma of chloroplast Plant
3. Explain the function of the Kreb's cycle, i.e. what occurs in the Kreb's cycle?
 
 
 
 
 

 

 In the Kreb's cycle pyruvate is broken down to carbon dioxide. In the process the energy in the pyruvated is extracted and transferred to 8NADH2, 2 FADH2 and 2ATPs
4. Describe what happens to FADH2 produced in the Kreb's cycle. 
      Where does it go? 

      What happens to the electrons? 
 
 
 
 

      What happens to the H+ ions? 
 
 

      How many ATPs can be produced?
 
 

 

 The FADH2 goes to the E. T. S. 
 

The electrons are passed off to Q and they go down the electron transport chain ultimately to be picked up by O2 forming water. 
 

The H+ of the FADH2 is actively transported out of the membrane using the energy of the electrons. 
 

Two pairs of H+ ions are transported into the outer compartment and as they return to the matrix through the F1 particle enough energy is released to make 2 ATPs.
5. Identify the function in respiration (if any) of each of the following:

Q
 
 
 
 

ATP Synthase (F1 particle)
 
 

Oxaloacetate
 
 

NADP

O2
 

H atom carrier in the E.T.S. that picks up H atoms and transports the H+ ion into the matrix at the same time it transfers the electron to the next electron carrier in the chain.
 

H+ protein channel through which H+ ions return to the matrix releasing energy which is used to make ATP

The four carbon compound in the matrix that binds with Acetyl Co A to start the Kreb's cycle proper.

NADP does not function in respiration.

O2 is the final electron acceptor. It picks up electrons at the end of the respiratory chain and forms water
6. Identify the function in photosynthesis (if any) of each of the following:
 
 

Photosystems
 
 
 

Ribulose biphosphate
 

PQ
 
 
 

Light energy
 
 
 

NADP

 
 
 

Photosystems are clusters of chlorophyll that absorb light energy to be used to make ATP and NADPH in the light dependent reactions

5-carbon compound that reacts with CO2 to start the Calvin cycle (light independent reactions).

Hydrogen atom carrier that accepts H atoms and transports the H+ ion into the thylakoid space as the electron continues down the carrier chain.

Light energy is used as the energy source to drive photosynthesis. It is captured in ATP and NADPH to be used in converting CO2 and H2O into glucose
 

NADP is a H atom carrier that picks up an electron (rich in energy) and a H+ ion forming NADPH that will be used as a source of hydrogen and energy for making glucose.
7. Indicate by an X the stage of photosyn- thesis (if any) in which each of the following is used:
                                                               CO2

PQ

Ribulose biphosphate

NADP

 

                                                                      Light dependent           Light independent Reactions                     Reactions

                                              X

         X

                                              X

         X
8. A. Explain why photosynthesis and respiration appear to be the reverse of each other. 
 
B. Explain why, in fact, they are not the reverse of each other.		 The products of photosynthesis (C6H12O6 and O2) are the reactants of respiration and the products of respiration (CO2 and H2O) are the reactants of photosynthesis

These two processes are important energy conversions. Energy enters as light and in photosynthesis is converted to chemical bond energy in the glucose. In respiration the energy of the glucose is transferred into ATP for use. When the ATP is used, the energy is converted to heat. The energy follows a linear flow not a circular one.

 
9. Indicate by an X the stage of respiration (if any) in which each of the following is used:
          O2
    Glucose

    FAD

    CO2

    Acetyl Co A

    Oxaloacetate

 Glycolysis              Krebs                 E.T.S.

                                                           X

      X

                                 X

            Not used at all in respiration

                                 X

                                 X
10. A plant has a photosynthetic curve as shown in green. It has a respiration curve as shown in blue.
 

Would the plant likely be able to grow?

Explain why or why not.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Yes

It makes more glucose during photo-synthesis than is used day and night in respiration. The excess would be available for producing new plant tissues.
11. A pigment has the absorption spectrum shown below.
 
 
 
 
 
 
 
 
 
 

A) Could this pigment be used to absorb light for photosynthesis?
B) Could this pigment be used as the only pigment for photosynthesis?
C) Explain your answer to part B.

     
D) What color might this pigment appear to us?
 
 
 
 
 
 
 
 
 
 
 

Yes
No
The pigment absorbs only the blue end of the spectrum and photosynthesis uses both red and blue energy
 
 

d) This pigment might appear orange red.
12. Identify 2 ways that animals are dependent upon plants? 1) Animals are dependent upon plants for glucose (source of building blocks for all carbohydrates and source of energy for respiration) 

2)Animals are also dependent upon plants for O2 for respiration.
13. What do the letters ATP stand for? Adenosine TriPhosphate
14. Why is ATP important in cells? ATP is the cell's source of energy to do work. The amount of energy in ATP is an appropriate for the specific jobs the cell needs to carry out (active transport, phagocytosis, production of proteins, lipids, carbohydrates, etc)
15. Where in the ATP molecule is the usable energy located? The energy is found in the phosphate bonds.
16. Identify 3 cellular processes we have studied (as specific as possible) for which ATP is used.
 
 
 
 
 
 
 
 

 

 ATP is used for 
       active transport, 
       phagocytosis, 
       exocytosis, 
       synthesis of proteins, lipids, carbohydrates, 
       muscle contraction, 
       movement of flagella and cilia. 
       It is also used to start glycolysis.
17. To investigate the effect of light intensity on the rate of photosynthesis you set up 5 test tubes of water (A, B, C, D, and E). You put Elodea, an aquatic plant into tubes A, B, C, and D. You cover tubes D and E with aluminum foil. Tube A you place 3 inches away from a light source, tube B 18 inches from the light source and tube C 18 inches from the same light source. You measure Moles of CO2 dissolved in the water before the experiment begins and 2 hours later and obtain the results below.
 
 
 
 
 

                   Tube    A       B      C      D     E

Moles CO2 before   40     40     40     40   40 
Moles CO2 after        5     15     35     45   40

Change in moles    -35   -25      -5     +5     0

A) Why would change in CO2 concentration in the water be useful (appro-priate) as a measure of the rate of photosynthesis?

     
B) What conclusion can you draw from the data obtained in the experiment 

C) How can you explain the results in Tube D?

     
D) What did you learn from Tube E? Why is this information important?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Because CO2 is used in the process of photosynthesis. The plant would absorb the CO2 from the water and so decrease the amount of CO2 present in the water. The faster photosynthesis occurred, the more CO2 would be used.

The more intense the light the faster photosynthesis occurs.
 

Photosynthesis was not occurring in the dark, but respiration does continue in the dark, and CO2 is a product of respiration.
 

Tube E told you how much change in CO2 would occur in the absence of any plant or light. This is important to ascertain that the plant is responsible for the change in CO2 level.
18. Compare aerobic respiration with lactic acid in terms of the endproducts forms and the amount of ATP produced.
     
In aerobic respiration the end products are CO2 and water while in lactic acid the end product is lactic acid. 36-38 ATPs per glucose are possible in aerobic respiration while only 2 ATPs per glucose are formed in lactic acid fermentation.
19. Explain how lipids can be used to drive respiration when carbohydrates are not available.
Lipids can be digested to glycerol and fatty acids. The glycerol can be converted to PGAl and enter into glycolysis. The fatty acids are converted to Acetyl CoA which enters the Kreb's cycle.

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