Photosynthesis 3

Photosynthesis 3

By R Marsh Ph.D.

= FORM of electromagnet radiation

ENERGY = inversely related to its wavelength (ie, shorter wavelength pack more energy)

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Light

​What has the most energy?

Non-Ionized Radiation: Your cell phones (transmitter) use non-ionized waves to tramit your voice across the waves to a reciever where it is decoded.

Ionizing Radiation is a form of energy that acts by removing electrons from atoms and molecules of materials that include air, water, and living tissue.​​

• Only chlorophyll-a participates directly in the light reaction

• Other pigments have different absorption spectra

• Chlorophyll a

  • ABSORBS: red & Violet-blue wavelengths

  • REFLECTS: green wavelengths= reason plants “look green.”

PIGMENTS= light absorbing molecules

Multiple Choice

Chlorophyll absorbs a higher percentage of _____ and _______ light.

• purple & green light

• red & blue light

• black & orange light

• yellow & green light

Multiple Choice

Where does CO2 enter the leaves through?

• Roots
• Stem
• Chloroplasts
• Stomata

Multiple Choice

Which pigment absorbs sunlight for photosynthesis?

• chloroplast

• thylakoid

• grana

• chlorophyll

1. LIGHT REACTION (Light Dependent Reaction)

   1. Sunlight energy split the Water that was absorbed from the plant roots

   2. Oxygen is released and Hydrogen is used to create ATP and NADPH

   3. Solar energy is converts into chemical energy, ATP and NADPH

TWO stages of Photsynthesis

1. CALVIN CYCLE

   (Light independent reactions)

   1. Uses energy from the light reaction (ATP and NADPH) to incorporate CO₂ from the atmosphere into sugar

Photsynthesis Stage 2

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Photsynthesis

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____ Thylakoid, ___Stroma, ____ LIght Reaction ____ Calvin Cycle___ Thylakoid Membrane

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Light Reaction

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The ions create an Electron Transport Chain​

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Sunlight is captured by Chlorophyll

One of the Electron captures split a water molecule in thylakoid space

Oxygen released from water splitting combines with another oxygen, released as O₂ to the atmosphere

Hydrogen released from water accumulates in the thylakoid space

Enzyme transfer 2 electrons to NADP+ to produce NADPH

H= ions in the thylakoid space provide energy to produce ATP as they diffuse down the concentration gradient back to the stroma

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Light Reaction

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Multiple Choice

Where in the chloroplast would chlorophyll be located?

• thylakoid membrane

• stroma

• cristae

• lysosome

Multiple Choice

A small amount of ATP is made during the light reactions during the _____________ process? This is a smaller version of an important process in respiration.

• splitting water

• electron transport chain

• carbon fixation

• citric acid cycle

Multiple Choice

What is an effect of light being absorbed by chlorophyll?

• an electron gains energy

• carbon is attached to RuBP

• Glucose is created

• Glucose is split into 2 parts

Multiple Choice

The molecules produced in the light reactions that are used in the Calvin cycle are:

• Oxygen and ATP

• NADPH and ATP

• Carbon Dioxide and NADPH

• Water and ATP

Multiple Choice

Hydrolysis is a word that describes this process in the light reactions that generates oxygen.

• attaching carbon atoms

• exciting electrons

• splitting water

• active transport

Uses energy from the light reaction to incorporate CO2 from the atmosphere into sugar

CALVIN CYCLE

Uses ATP and NADPH (made in light reaction) to convert CO₂ to sugar

ANABOLIC: uses energy to build sugar from smaller molecules

Carbon enters the cycle as CO₂ and leaves as sugar

Each turn of the Calvin Cycle fixes carbon

Uses 18 ATP and 12 NADPH’s to make 1 glucose. (6 turns)

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Where does the oxygen in the sugar come from? ( H₂O or CO₂)

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CALVIN CYCLE

Multiple Choice

This product of photosynthesis is a waste product for plants.

• water

• oxygen

• carbon dioxide

• glucose

Multiple Choice

The reactants of photosynthesis are...

• glucose and oxygen

• oxygen and carbon dioxide

• carbon dioxide and water

• water and glucose

Multiple Choice

Carbon fixation happens in what stage of photosynthesis?

• glycolysis

• light dependent reactions

• Calvin cycle

• citric acid cycle

Multiple Choice

What are the products of photosynthesis?

• water and carbon dioxide
• oxygen and glucose
• oxygen and carbon dioxide
• oxygen and water

Multiple Choice

What are the reactants of photosynthesis?

• carbon dioxide and oxygen
• water and oxygen
• carbon dioxide and water
• water and glucose