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PHOTOSYNTHESIS

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ENERGY AND LIFE

OBJECTIVES: 8.1

Explain where plants get the energy they need to produce food.

Describe the role of ATP (adenosine triphosphate) in cellular activities.

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Energy is the ability to do work.

Where does the energy that living things need come from?

__________, such as plants and some other organisms are able to use the energy from the sun to make their food.

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__________ get their energy from the foods they consume.

There are many different types of energy such as light, heat, etc.

Living things need energy also.

One of the principal compounds that cells use to store and release energy is ATP (adenosine, 5 ribose, 3 phosphates).

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___ is composed of______, five carbon _____ (ribose), and three ___________ groups.

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___ (adenosine diphosphate) is composed of adenine, ribose, and ___ phosphate groups.

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When a cell has energy available it can store it by adding a phosphate group to ADP making it ATP (the battery is fully charged).

When the chemical bonds between the _____ and _____ phosphate groups are broken, that stored energy is released.

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PHOTOSYNTHESIS: AN OVERVIEW

OBJECTIVES: 8.2

Explain what the experiments of van Helmont, Priestly, and Ingenhousz reveal about how plants grow.

State the overall equation of photosynthesis.

Describe the role of light and chlorophyll in photosynthesis.

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Jan van _______ designed an experiment to determine if plants grew by taking material out of the soil.

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The Experiment:

1. He determined the mass of a pot of dry soil and a small seedling.

2. He planted the seedling in the pot of soil.3. The plant was water regularly for 5 years.4. After 5 years the seedling had gained 75 kg

but the mass of the soil was almost unchanged.

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Conclusion:

Jan van Helmont concluded that the gain in ___ had come from the _____, because that was the only thing he added.

Van Helmont’s experiment accounts for the “hydrate”, or water part of the carbohydrate produced by photosynthesis.

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Joseph Priestley

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The experiment:

1. He took a candle, placed a glass jar over it, and watched as the flame gradually died out.

2. He reasoned there was something in the air that was necessary to keep it burning.

3. When that substance was used up, the candle went out.

4. He then placed a sprig of mint under the jar and allowed a few days to pass

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5. The candle was then relit and would remain lighted for a while.

Conclusion:

The mint plant produced the substance (oxygen – __) required for burning.

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__________ showed that the effect observed by Priestley only occurred when the plant was exposed to light.

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The ____________ equation:

6CO2 + 6H20 C6H12O6 + 6O2

Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen.

Photosynthesis also requires light and chlorophyll ( a molecule in chloroplast).

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Plants gather the sun’s energy with light-absorbing molecules called ________.

There are two main types of chlorophyll __ and __.

Chlorophyll absorbs light very well in the _______ and ___ regions of the visible spectrum (ROY G BIV).

Why does a plant not use green light effectively?

Plants also have a red and orange pigments (_______)

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THE REACTIONS OF PHOTOSYNTHESIS

OBJECTIVE: 8.3

Describe the structure and function of a chloroplast.

Describe what happens in the light-dependent reactions.

Explain what the Calvin cycle is.

Identify factors that affect the rate at which photosynthesis occurs.

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The chloroplasts contain saclike photosynthetic membranes called _________.

Thylakoids are arranged in stacks known as ______.

_________ in the thylakoids membrane organize chlorophyll and other pigments into clusters known as _____________ (light collecting units).

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There are two types of photosystems (read about p. 209-213).

1. ______________ (takes place in the _____).2. ________________ (Calvin cycle).

Factors that affects photosynthesis:

3. Water4. _____5. Intensity of light