Question

Lab Report 8: Energetics: Photosynthesis, Respiration, and Fermentation

Some leaves are variegated. That is, they display colors other than green (e.g. the Coleus plant).

Still other plants have leaves that contain areas of white. Use the information from the lab to

identify the probable source of ATP for plant cells located in the white regions of the leaf.

There is a mutation in corn that produces albino (white) plants. What is the potential for long-

term survival of these white corn plants? Explain.

Use the summary equations for photosynthesis, respiration, and the interaction of water and

carbon dioxide to explain the color changes observed with Elodea grown in Phenol Red.

Are yeast cells autotrophs or heterotrophs? Explain why you think so.

Explain the following statement.

All food energy ultimately comes from the sun.

Combustion of organic molecules (e.g. wood, fossil fuels, etc.) produces carbon dioxide, carbon

monoxide and other substances. Carbon dioxide and other gases are so-called greenhouse gases that can contribute to global warming and climate change. Based on the experiments and

demonstrations we have done today, what is an other effect might increased environmental

carbon dioxide might have on aquatic environments? (Hint: Phenol Red color change)

What kinds of approaches might reduce the amounts of carbon dioxide accumulating in the

atmosphere?

What is the meaning of the quotation at the beginning of this lab exercise?

Answer 1

Mutation cause the formation of white patches on the leaf and leads to leaf variegation. Loss of ATP dependent metalloprotease results in variegated leaf.
There is absence of thyllakoid in plastids.

Probable source of energy in white region is by cellular respiration.

-Mutation in corn plant caused production of white or albino plants and hence they have lost chloroplast and so for long term survival the plant undergo cellular respiration in mitochondria for energy production.

- It took 45min. To one hour for phenol red to change from yellow back to red. This colour alteration represent that Elodea plant is doing photosynthesis and Carbon dioxide is taken up from the phenol red solution.

- Yeast cells are heterotrophs as they are dependent on other organism for the food source and undergo heterotrophic mode of nutrition.

- All the food energy ultimately comes from sun as it is the photosynthesis that traps the energy emitted from the sun in the chain and results in conversion of complex form to simoler substances.

- In Elodea plant the photosynthesis process occuring results in increase in Carbon dioxide concentration and hence there was a colour change which leads to pH change in water body.

Accumulation of Carbon dioxide in atmosphere can be reduced by
1. Afforestation
2. Drive less
3. Less use of air conditioner
4. No fossil fuel burning

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