Photosynthesis POGIL answers

1b. Is this organelle more likely to be found in animal cells or plant cells?

Plant cells

2. The structures inside the organelle in Model 1 are called thylakoids. What compound necessary for photosynthesis is contained in the thylakoids?

Chlorophyll

3a. What substances are the reactants in photosynthesis? Include the name and chemical formula of each substance in your answer.

Carbon dioxide- CO₂ and Hydrogen dioxide- H₂O

3b. Where in the organelle are these molecules stored before they are used in photosynthesis?

The Stroma

3c. Is photosynthesis an endergonic or exergonic reaction? Support your answer with evidence from Model 1.

Exergonic because it releases energy into the plant cell

3d. What is the energy source for photosynthesis?

Sunlight

4a. What is another name for the light-independent reactions?

The Calvin cycle

4b. In what part of the chloroplast do the light-dependent reactions occur?

The thylakoid

4c. In what part of the chloroplast do the light-independent reactions occur?

The stroma

5. Considering your answers to question 4, what compound is best able to absorb the light energy from the sun and convert it into chemical energy?

Chlorophyll

6. What substances are produced during photosynthesis? Include the name and chemical formula of each substance in your answer.

Glucose- C₆H₁₂O₆, Oxygen- O₂, and Hydrogen dioxide- H₂O

7. Why is it necessary to have six CO₂ entering the chloroplast?

So that there will be 6 Carbons in the glucose

In Model 2, what shape or symbol represents a single electron?

A black dot

9a. Find two places in Model 2 where electrons are released from chlorophyll by a photon of light coming from the sun.

At photosystem I and II

9b. Find one place in Model 2 where electrons are released from water molecules.

The inner thylakoid

9c. When the electrons are released from water molecules, what other products are formed?

H⁺ and O₂

10. In Model 2, label the diagram with "A", "B", and "C" to indicate where the three steps in the box are occurring.

"A" occurs in Photosystem II, "B" occurs in the ETC, and "C" occurs in the ATP synthase

11. The light-dependent reactions include an electron transport chain system that works in a very similar fashion to the electron transport chain in respiration. Briefly describe how this system works and what job it performs in the light-dependent reactions. (Your answer should include a discussion about concentration gradient.).

The electrons go against the concentration gradient and then something happens

12a. Name the embedded protein complex found in the thylakoid membrane that uses excited electrons the reduce NADP+ into NADPH.

Photosystem I

12b. Name the embedded protein complex found in the thylakoid membrane that uses excited electrons to the electron transport chain.

Photosystem II

12c. Name the embedded protein complex found in the thylakoid membrane that uses excited electrons.

ATP Synthase

13a. Once a chlorophyll molecule has released electrons it is no longer useful until those electrons are replaced. What is the source of replacement electrons for those released from photosystem I?

Electron transport chain

13b. What is the source of replacement electrons for those released from photosystem II?

Electrons from the splitting of water

14. Is carbon dioxide involved in light-dependent reactions?

No

15b. 12 water molecules are shown as reactants, but six water molecules are shown as products. Are any of the 12 water molecules products of the light-dependent reactions?

No, water molecules are not products in the light-dependent reactions of photosynthesis.

16. Where do the ATP and NADPH produced during the light-dependent reactions go when the process is complete?

Calvin cycle (light-independent cycle)

17. What are the three phases of the calvin cycle?

Carbon fixation, regeneration, reduction.

20. Explain what happened to the carbon atoms from the carbon dioxide molecules that entered the Calvin cycle.

Carbon fixation turns it into PGA

21. What is carbon fixation?

Carbon atoms are removed from atmosphere and incorporated I to larger molecules within the plant.

22a. What molecule does the PGA molecule turn into during the reduction phase of the Calvin cycle?

PGA molecule turns into PGAL

22b. Describe how the structures if the PGA and PGAL are different?

The PGA molecule loses an oxygen as it turns into PGAL

22c. Identify types and numbers of molecules that provide the free energy necessary for the reduction of the PGA molecule.

6 ADP, 6 NADH

23a. How many water molecules are produced in the reduction phase of the Calvin cycle?

Six

23b. In the reduction phase of the Calvin cycle, water is produced. Explain where the hydrogen and oxygen atoms in these water molecules originated.

The oxygen for the water molecule was removed from the PGA as it turned into PGAL. THe hydrogen atoms came from the conversion of NADPH to NADP

25a. How many PGAL molecules will it take to make one moleucle of glucose?

Two PGAL molecules will be needed. Each PGAL molecule contains three carbon atoms, but a glucose molecule contains six carbon atoms

25b. How many turns of the Calvin cycle will it take to make one molecule of glucose?

One

26. Where do the ADP and NADP+ go after they are used in the Calvin cycle?

They travel back to the thylakoid to be recycled in the light-dependent reaction

27. How do light-dependent and light-independent depend on each other.

18 ATp molecules and 12 NADPH molecules produced during the light-dependent cycle are needed to power the light-independent cycle

29. Throughout photosynthesis, energy is transferred from light to several molecules increasingly higher potential energy.

Sunlight → Electrons → ATP → Glucose