Adenine Ribose 3 Phosphate groups

Section 8-1

ATP

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Adenosine Triphosphate = ATP

Chemical compound which stores energy

Cellular Energy used to:•Break or form chemical bonds•Change the shape of proteins•Move molecules across plasma membrane (Active transport)•Move cells (flagellum)

ADP ATP

Energy

EnergyAdenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)

Partiallychargedbattery

Fullychargedbattery

Section 8-1

Figure 8-3 Comparison of ADP and ATP to a Battery

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ADP ATP

Energy

EnergyAdenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)

Partiallychargedbattery

Fullychargedbattery

Section 8-1

Figure 8-3 Comparison of ADP and ATP to a Battery

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Photosynthesis

How did we figure out how plants work?

Jan van Helmont• Thought plants grew by taking material out of soil• Planted a seedling in a pot of soil• Watered daily• After 5 years the tree gained 75 kg• Soil mass did not change• Figured out the -hydrate part of carbohydrate

How did we figure out how plants work?Joseph Priestly• Placed a glass jar over a lit candle• The flame went out• Placed a live sprig of mint under the jar• The candle burned much longer • Deduced that the plant produced a substance needed for burning (oxygen)

How did we figure out how plants work?

Jan Ingenhousz•Priestly’s experiment only worked in sunlight•Deduced that sunlight is required for oxygen to be made by plants

Light Energy

Chloroplast

CO2 + H2O Sugars + O2

Section 8-2

Photosynthesis: Reactants and Products

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Absorption of Light byChlorophyll a and Chlorophyll b

V B G YO R

Chlorophyll b

Chlorophyll a

Section 8-2

Figure 8-5 Chlorophyll Light Absorption

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Chlorophyll• Light absorbing molecule (pigment)• Reflects green light wavelength (that’s why plants are green)• Light energy excites electrons• 2 types (a & b)• Chlorophyll a absorbs red & violet wavelengths• Chlorophyll b absorbs blue, orange, & red wavelengths

Chlorophyll

Translation?  Plants under yellow & green light will carry out photosynthesis at a lower rate than the same type of plant under other colors (blue, violet, red). 

Inside a Chloroplast

Chloroplast Vocabulary

Thylakoids – Photosynthetic membranesGrana – Stacks of thylakoidsStroma – Region outside of the thylakoid membranes

Light Dependent Reactions occur within the thylakoidsThe Calvin cycle occurs in the stroma

Light Dependent ReactionsThe light reactions use light & water which produce the oxygen "waste product". 

Light dependent reactions = photolysis

Photolysis translates as light (photo-) splits (-lysis)

The light energy is used to split the water molecule, which produces H+ & O- ions.

Chloroplast

Light

O2

Sugars

CO2

Light-Dependent Reactions

CalvinCycle

NADPH

ATP

ADP + PNADP+Chloroplast

Section 8-3

Figure 8-7 Photosynthesis: An Overview

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HydrogenIon Movement

Photosystem II

InnerThylakoidSpace

ThylakoidMembrane

Stroma

ATP synthase

Electron Transport Chain Photosystem I ATP Formation

Chloroplast

Section 8-3

Figure 8-10 Light-Dependent Reactions

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Excited electronsElectron transport = Electrons are moved by carrier molecules

Nicotinamide adenine dinucleotide phosphate =(Holds 2 high energy electrons & a hydrogen ion)This changes the molecule to NADPH

NADP+

Hydrogen Ion Concentrations• Hydrogen ions are pumped (via proton pump) into the thylakoid

• Concentration of hydrogen ions fuels the production of ATP from ADP as the hydrogen ions are sent back across the thylakoid membrane through an ATP synthase

Section 8-3

Figure 8-10 Light-Dependent Reactions

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ADP ATP

NADP+ NADPH

Light Dependent Reactions End-Products

Photosynthesis

includes

of

take place intakes place in uses

to produce to produce

use

Light-dependentreactions

Calvin cycle

Thylakoidmembranes Stroma NADPHATPEnergy from

sunlight

ATP NADPH O2 Chloroplasts High-energysugars

Section 8-3

Concept Map

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Calvin Cycle = Light Independent Reactions or Dark Reactions

• ATP & NADPH are not stable• Energy needs to be changed into a stable form for storage

ChloropIast

CO2 Enters the Cycle

Energy Input

5-CarbonMoleculesRegenerated

Sugars and other compounds

6-Carbon SugarProduced

Section 8-3

Figure 8-11 Calvin Cycle

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RuBP

PGA

PGAL

Calvin Cycle Summary6 carbon dioxide molecules bond to six 5-carbon molecules to produce twelve 3-carbon molecules

ATP & NADPH (from light dependent reactions) are used to convert twelve 3-carbon molecules into higher energy forms

Two 3-carbon molecules are removed from the cycle and used by the plant to form compoundsThe remaining ten 3-carbon molecules are converted into six 5-carbon moecules which are used in the next cycle

Photosynthesis Summary

Photosynthesis Summary