BIOLOGY: CH. 7 PHOTOSYNTHESIS: USING LIGHT TO MAKE FOOD

Harness sunlight, Thylakoid, Light Reaction

"Photo"

Making sugar, Stoma, Calvin Cycle

"Synthesis"

3 Categories of Plants; Hot, Dry Weather and how they survive?

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Draw out the light reaction.

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Enzymatic Reaction; Name all key players and how does it affect energy?

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Steps to Cellular Respiration, where it occurs & Inputs and Outputs?

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1. Carbon Fixation 2. Sugar Creation 3. Regeneration

3 Reactions of the Calvin Cycle?

What is the chemical equation for photosynthesis?

6CO2 + 6H2O ---> C6H12O6 + 6O2

Photon

A fixed quantity of light energy. The shorter the wavelength of light, the greater the energy of the photon.

Chlorophyll

A light absorbing pigment in chloroplasts that plays a central role in converting solar energy to chemical energy.

Photosystem

A light harvesting unit of a chloroplast's thylakoid membrane; consists of several hundred molecules, a reaction center chlorophyll, and a primary electron acceptor.

What is a photon?

A photon is a fixed quantity of light energy. The shorter the wavelength of light, the greater the energy of the photon.

Stomata

A pore surrounded by guard cells in the epidermis of a leaf. When stomata are open, CO2 enters the lead, and water and O2 exit. A plant conserves water when its stomata are closed.

Grana

A stack of hollow disks formed of thylakoid membrane in a chloroplast. Grana are the sites where light energy is trapped by chlorophyll and converted to chemical energy during the light reactions of photosynthesis.

Stroma

A thick fluid enclosed by the inner membrane of a chloroplast. Sugars are made in the stroma by the enzymes of the Calvin Cycle.

The Calvin cycle uses the products of the light reactions to make sugar from carbon dioxide.

ATP generated by the light reactions provides the energy for sugar synthesis. The NADPH produced by the light reactions provides the high-energy electrons that drive the synthesis of glucose from carbon dioxide. Thus, the Calvin cycle indirectly depends on light to produce sugar because it requires the supply of ATP and NADPH produced by the light reactions.

Carotenoids

Absorb mainly blue-green light and absorb and dissipate excessive light energy that might damage chlorophyll.

NADPH

An electron carrier (a molecule that carries electrons) involved in photosynthesis. Light drives electrons from chlorophyll to NADP+, forming NADPH, which provides the high energy electrons for the reduction of carbon dioxide to sugar in the Calvin Cycle.

Chloroplasts

An organelle found in plants and photosynthetic protists. Enclosed by two membranes, a chloroplast absorbs sunlight and uses it to power the synthesis of organic food molecules (sugar).

CAM plants

Are adapted to very dry climates and open their stomata only at night to conserve water.

The Calvin Cycle occurs in the A. Thylakoid B. Stroma C. Stomata D. Grana E. Mitochondria

B

Why are plants green? A. They absorb green. B. They reflect green. C. They produce green. D. They synthesize green. E. They love green.

B

The pores on leaves for gas exchange are called A. Thylakoid B. Stroma C. Stomata D. Grana E. Mitochondrial

C

C3

C3 plants go through the Calvin cycle, taking in carbon dioxide through the leaves' minuscule pores, called stomata. An enzyme called RuBisCO helps the carbon dioxide combine with sugar. Eventually, the sugar and carbon dioxide form a molecule with three carbon atoms (C3) in the chloroplast.

Calvin Cycle Outputs

C6H12O6

Cellular Respiration Outputs

CO2, H2O & ATP

In the light reactions...

Chlorophyll in the thylakoid membranes absorbs solar energy, which is then converted to the chemical energy of ATP and NADPH, and water is split, providing a source of electrons and giving off O2 gas as a by-product.

C4 plants

Close their stomata to save water during hot and dry weather and can still carry out photosynthesis.

Where does energy come from?

Comes from the sun.

CAM

Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions. In a plant using full CAM, the stomata in the leaves remain shut during the day to reduce evapotranspiration, but open at night to collect carbon dioxide (CO2).

The main product of photosynthesis is? A. Oxygeb B. Carbon Dioxide C. ATP D. Glucose E. NADPH

D

How do molecules move across the plasma membrane?

Diffusion, Osmosis, Facilitative Diffusion, Active & Passive Transport, & Exocytosis and Endocytosis.

What are the two major products of the Light reaction? What is the bi-product?

During the process of photosynthesis, we obtain, C6H12O6 (glucose) as the main product & NADPH and oxygen as the byproduct. This process has two reactions: light reaction and dark reaction.

Which enzyme is responsible for converting ADP + P into ATP? A. Amalyse B. Maltese C. Lactase D. ADP Synthase E. ATP Synthase

E

Photosynthesis Inputs

H2O, Light & CO2

Radiowaves Microwaves Infared UV X-rays

Increasing Wavelengths

Chlorophyll b

Is very similar to chlorophyll a, absorbs mainly blue and orange light, and conveys absorbed energy to chlorophyll a.

Photo-

Light

Synthesis-

Making sugar

Calvin Cycle Inputs

NADPH, ATP & CO2

Cellular Respiration Inputs

O2 & C6H12O6

Photosynthesis Outputs

O2, Sugar, C6H12O6

Thylakoid

One of a number of disk shaped membraneous sacs inside a chloroplast. Thylakoid membranes contain chlorophyll and the enzymes of the light reactions of photosynthesis. A stack of thylakoids is called a grana.

Chlorophyll a

Participates directly in the light reactions and absorbs mainly blue-violet and red light.

Look at the two equations below and determine what each represents. 6H2O + 6CO2 = Sun ---> 6O2 + C6H12O6 6O2 + C6H12O6 = Sun ---> 6H2O + 6CO2

Photosynthesis & Cellular Respiration

How does the first photosystem (Photosystem II) actually return to its original state after it is oxidized by light?

Photosytem II returns to its original state after it is oxidized by light when through Water Splitting: 2e-, 2H+, and 1/2 O2.

Why are plants green?

Plants absorb every other color but green and reflect green.

What takes place in the Calvin Cycle?

Plants obtain all of their energy from the Sun. Each plant cell has a small organelle known as a chloroplast that captures energy from the Sun. Inside the chloroplasts, a plant's chlorophyll pigments undergo photosynthesis to convert the energy from the Sun into sugar and carbon dioxide. The carbon dioxide is released into the atmosphere and then recaptured by the plant to undergo the Calvin cycle. Carbon dioxide enters the chloroplasts and combines with a five-carbon sugar known as ribulose 1,5-bisphosphate. The enzyme RuBisCo catalyzes this reaction. Next, the reaction forms a six-carbon intermediate that decays into two molecules of the three-carbon compound 3-phophglyceric acid. Next, the acid is converted into glyceraldehyde 3-phosphate, which is a precursor to glucose. The glyceraldehyde 3-phosphate is converted back to ribulose 1,5-bisphosphate to complete the cycle. In total, for every three molecules of carbon dioxide that enter the Calvin cycle, one molecule of glyceraldehyde 3-phosphate is formed. This molecule can then be converted into glucose for the plant to use for energy.

Two forms of energy?

Potential & Kinetic energy.

What is the Protein Pump and where is it located?

Protein pumps use energy from hydrolysis of ATP to move ions or large molecules across cell membrane (low to high concentration) and are located in the mitochondria.

What are the 2 major events of photosynthesis?

The Light Reactions (the photo part) and the Calvin Cycle (the synthesis part).

What is a chloroplast and where does photosynthesis take place in the chloroplast?

The chloroplast is an organelle found in plants and photosynthetic protists. Enclosed by two membranes, a chloroplast absorbs sunlight and uses it to power the synthesis of organic food molecules (sugar). Photosynthesis takes place in the Thylakoid.

Wavelength

The distance between crests of adjacent waves, such as those of the electromagnetic spectrum including light.

Light Reaction

The first of two stages in photosynthesis, the steps in which solid energy is absorbed and converted to chemical energy in the form of ATP and NADPH. The light reactions power the sugar producing Calvin Cycle but produce no sugar themselves.

Electromagnetic Spectrum

The full range of radiation, from the very short wavelengths of gamma rays to the very long wavelengths of radio signals.

Carbon Fixation

The initial incorporation of carbon from CO2 into organic compounds by autotrophic organisms such as photosynthetic plants, algae, or bacteria.

In which part of the chloroplast does each stage occur?

The light reaction takes place in the thylakoids and the calvin cycle takes place in the stroma.

Photosynthesis

The process by which plants, algae, and some bacteria transform light energy to chemical energy stored in the bonds of sugars. This process requires an input of carbon dioxide (CO2) and water (H2O) and produces oxygen gas (O2) as a waste product.

Calvin Cycle

The second of two stages of photosynthesis; a cyclic series of chemical reactions that occur in the stroma of a chloroplast, using the carbon in CO2 and the ATP and NADPH produced by the light reactions to make the energy rich sugar molecule G3P, which is later used to produce glucose.

What are the 3 types of photosynthetic pathways?

The three photosynthetic pathways are called C3, C4, and CAM. Most plants use the C3 metabolic pathway.

C4

These are cells that are located toward the surface of a plant leaf and are where photosynthesis typically occurs. However, in C4 plants, these cells are exposed to oxygen and have no RuBisCO to do photosynthesis. 3. The CO2 joins with another carbon compound to make a C4 chemical called oxaloacetic acid.

C3 plants

Use CO2 directly from the air and are very common and widely distributed.