bio ppt chloroplast project

erratum erratum

Cover page of Handout:Cover page of Handout:

““Handout Contents – Handout Contents –

Annex A: Chlorophyll and Light Absorptions” Annex A: Chlorophyll and Light Absorptions”

““This document consists of 11 printed pages.”This document consists of 11 printed pages.”

CHLOROPLASTSCHLOROPLASTSthe mini factories in leavesthe mini factories in leaves

overview of presentation overview of presentation

1. Iron Chlorosis – Causes, Effects & Solutions

2. Introduction to Chloroplast

3. Chloroplasts and Light-Dependent Reactions 4. Chloroplasts and Calvin Cycle Reactions 5. Structure-Function Relationship

Iron ChlorosisIron Chlorosis

iron chlorosis iron chlorosis

Iron Chlorosis is a disease in the leaves that lead Iron Chlorosis is a disease in the leaves that lead to the yellowing of leaves. to the yellowing of leaves.

Hence, Iron chlorosis reduces the amount of Hence, Iron chlorosis reduces the amount of chlorophyll available in plants. chlorophyll available in plants.

Yellowing of leaves is due to the lack of chlorophyll Yellowing of leaves is due to the lack of chlorophyll pigments in plants.pigments in plants.

What exactly causes iron chlorosis? Let’s explore... What exactly causes iron chlorosis? Let’s explore...

causes of iron chlorosis causes of iron chlorosis

Iron is an essential micronutrient in the plant.Iron is an essential micronutrient in the plant.

Deficiency in iron will lead to iron chlorosis because Deficiency in iron will lead to iron chlorosis because iron is required in the biosynthesis of chlorophyll.iron is required in the biosynthesis of chlorophyll.

Deficiency in iron usually occurs when pH of soil is Deficiency in iron usually occurs when pH of soil is 7 and above. Why?7 and above. Why?

QQUUIIZZ

pH 7 and above = alkalipH 7 and above = alkali

Iron + alkali Iron + alkali Iron hydroxide + water Iron hydroxide + water

Fe(OH)Fe(OH)22 is insoluble is insoluble reduction in iron content. reduction in iron content.

biosynthesis of chlorophyllbiosynthesis of chlorophyll


Porphyrins (a group of chemical compounds) occur Porphyrins (a group of chemical compounds) occur in nature and in bio-inspired synthetic catalysts.in nature and in bio-inspired synthetic catalysts.

Porphyrin with an iron in the centre is called heme.Porphyrin with an iron in the centre is called heme.

Heme which acts as a catalyst influence the Heme which acts as a catalyst influence the chlrophyll synthesis. chlrophyll synthesis.

Thus, when iron deficiency occurs chlorophyll Thus, when iron deficiency occurs chlorophyll synthesis may be impaired. synthesis may be impaired.


structures of chlorophyll pigments.

Can you spot the main similarity?


FeFe2+2+

porphyrin structuresused in chlorophyll synthesis – with an iron in centre (heme)

With iron-With iron-deficiency, deficiency, this this compound compound will not will not form. This form. This will affect will affect the the production production of of chlorophyll chlorophyll leading to leading to Iron Iron Chlorosis.Chlorosis.

effects of iron chlorosis effects of iron chlorosis

The main effect is the yellowing of leaves. The main effect is the yellowing of leaves.

healthy healthy leavesleaves leaves leaves

affected affected by Iron by Iron ChlorosisChlorosis

effects of iron chlorosis effects of iron chlorosis

Sometimes it may change yellow to white and Sometimes it may change yellow to white and finally brown. This happens when iron chlorosis is finally brown. This happens when iron chlorosis is left untreated. This may lead to death of tree. left untreated. This may lead to death of tree.

So, what are the treatments available for Iron So, what are the treatments available for Iron Chlorosis? Lets explore..!Chlorosis? Lets explore..!

Healthy zoneHealthy zone Dangerous ZoneDangerous Zone

soil testing soil testing

Before treating the affected plants and trees, soil testing Before treating the affected plants and trees, soil testing must be performed. must be performed.

The main purpose is that it allows us to know the pH of The main purpose is that it allows us to know the pH of the soil.the soil.

Dig down 6 to 8 inches in Dig down 6 to 8 inches in several different locations. several different locations. Collect soil from these Collect soil from these locations and mix them locations and mix them together. together.

A portion of the mixture A portion of the mixture is then used for testing. is then used for testing.

treatments for iron chlorosis treatments for iron chlorosis

Main treatments for Iron Chlorosis Main treatments for Iron Chlorosis

Foliar Treatment Foliar Treatment

Foliar spray of iron sulphate or iron chelate solution Foliar spray of iron sulphate or iron chelate solution applied to leaves applied to leaves




Soil treatmentSoil treatment

This method refers to the lowering of soil’s pH. This This method refers to the lowering of soil’s pH. This is a long-term solution. is a long-term solution.

But it is also the difficult method as correct amount But it is also the difficult method as correct amount of iron sulphate need to be added so as to prevent of iron sulphate need to be added so as to prevent the soil from getting too acidic. the soil from getting too acidic.



Trunk Injection and ImplantationTrunk Injection and Implantation

These methods involve the These methods involve the necessary chemical being necessary chemical being injected or implanted into the injected or implanted into the tree by creating holes in the tree by creating holes in the tree. tree.

This is the most effective way This is the most effective way to green up iron chlorotic to green up iron chlorotic trees.trees.

State a disadvantage of the Trunk Injection and State a disadvantage of the Trunk Injection and Implantation method.Implantation method.

QQUUIIZZ

Creating holes will encourage the entry of bacteria Creating holes will encourage the entry of bacteria decomposition of the part with hole. Eventually, decomposition of the part with hole. Eventually, the whole tree/plant may die.the whole tree/plant may die.



Animation on Iron ChlorosisAnimation on Iron Chlorosis

http://bcs.whfreeman.com/thelifewire/content/chp37/37020.html

iron chlorosis iron chlorosis

ChloroplastsChloroplasts

introduction to chloroplasts introduction to chloroplasts

CHLOROPLASTSCHLOROPLASTSThe biochemical process The biochemical process called photosynthesis called photosynthesis occurs in this organelleoccurs in this organelle

They are only found in They are only found in plant cells and plant cells and photosynthetic bacteria.photosynthetic bacteria.

structure of chloroplast structure of chloroplast

Chloroplasts are surrounded by Chloroplasts are surrounded by double membrane.double membrane.Inner membrane contains a Inner membrane contains a semi-fluid called stroma.semi-fluid called stroma.In the stroma, interconnected In the stroma, interconnected thylakoids are found.thylakoids are found.A stack of thylakoids = granum A stack of thylakoids = granum (pl: grana)(pl: grana)Chlorophyll pigments are Chlorophyll pigments are embedded on the thylakoids.embedded on the thylakoids.

structure of chloroplast structure of chloroplast

Why are chloroplasts surrounded by double-Why are chloroplasts surrounded by double-membrane? membrane? QQ

UUIIZZ

This is to entirely separate the reactions taking This is to entirely separate the reactions taking place in chloroplast from the reactions taking place in chloroplast from the reactions taking place in cytoplasm.place in cytoplasm.

introduction to chloroplasts introduction to chloroplasts

Chloroplast AnimationChloroplast Animation

http://www.cnr.vt.edu/DENDRO/forestbiology/photosynthesis.swf

PhotosynthesisPhotosynthesis

photosynthesis in chloroplasts photosynthesis in chloroplasts

The only function of chloroplast is to carry out the The only function of chloroplast is to carry out the photosynthesis. photosynthesis.

Photosynthesis is separated into two main parts:Photosynthesis is separated into two main parts:

1. Light Dependent Reaction (LDR)1. Light Dependent Reaction (LDR)

2. Calvin Cycle Reactions2. Calvin Cycle Reactions

Lets explore this Lets explore this briefly soon..briefly soon..

photosynthesis in chloroplasts photosynthesis in chloroplasts

QQUUIIZZ

1.1. Does not reflect LDR and Calvin Cycle ReactionDoes not reflect LDR and Calvin Cycle Reaction

2. Only visible light – a small part of the 2. Only visible light – a small part of the electromagnetic spectrum – is used.electromagnetic spectrum – is used.

3. Certain wavelengths are more important that 3. Certain wavelengths are more important that others.others.

The general equation of photosynthesis is The general equation of photosynthesis is

6CO6CO22 + 6H + 6H22O CO C66HH1212OO66 + 6O + 6O22LIGHT LIGHT

ENERGYENERGY

The above equation is OVER-simplified. Explain whyThe above equation is OVER-simplified. Explain why

light dependant reaction light dependant reaction

This reaction takes place in thylakoids. This reaction takes place in thylakoids. LI

GH

T

LIG

HT

1. Light is 1. Light is absorbed absorbed by the by the chlorophyll chlorophyll embedded embedded in in thylakois.thylakois.

2. Electrons 2. Electrons of of chlorophyll chlorophyll are boosted are boosted and they and they are emitted.are emitted.

3. This 3. This stimulates stimulates the splitting the splitting of Hof H22O. OO. O2 2 is is released.released.

ee

e e


This reaction takes place in thylakoids. This reaction takes place in thylakoids.

ee

e e3. These 3. These electrons electrons are carried are carried by carriers. by carriers. At this part, At this part, some some energy is energy is released.released.

4. The 4. The energy energy released is released is used by used by cytochromes cytochromes to pump to pump protons. protons. This creates This creates a Ha H++ gradient.gradient.

4. H4. H+ + will will then diffuse then diffuse back back through a through a protein. This protein. This protein protein which is also which is also an enzyme an enzyme will use the will use the ions to form ions to form ATP (energy ATP (energy molecule)molecule)


The unused electrons may be used for 2 purposed:The unused electrons may be used for 2 purposed:

1. they will be used to synthesise ATP again using 1. they will be used to synthesise ATP again using the previous methodthe previous method

2. Combine with Hydrogen Ions to reduce NADP to 2. Combine with Hydrogen Ions to reduce NADP to NADPHNADPH


The final step of LDR is non-cyclic DR:The final step of LDR is non-cyclic DR:

electrons emitted from electrons emitted from waterwater is used to produce is used to produce NADPHNADPH

calvin cycle reactions calvin cycle reactions

This reaction is divided into three parts:This reaction is divided into three parts:

1. CO1. CO22 Fixation Fixation

COCO22 and 5-carbon RuBP form 6 carbon molecule. and 5-carbon RuBP form 6 carbon molecule.

They then split two 3-carbon molecules.They then split two 3-carbon molecules.

This is catalysed by RuBP carboxylase. This is catalysed by RuBP carboxylase.

QQUUIIZZ

The enzyme acts VERY slowly. So high amount of The enzyme acts VERY slowly. So high amount of enzyme will increase the reaction rate.enzyme will increase the reaction rate.

Why is the RuBP caboxylase found in great Why is the RuBP caboxylase found in great abundance in chloroplast?abundance in chloroplast?



2. Reduction of CO2. Reduction of CO22

The 3-C molecules (PGA) is reduced to PGALThe 3-C molecules (PGA) is reduced to PGAL

NADPH and ATP are used in this reaction.NADPH and ATP are used in this reaction.

PGAL is then used to convert to various organic PGAL is then used to convert to various organic molecules. molecules.

QQUUIIZZ

ATP – Provides energy; NADPH – Provides electronsATP – Provides energy; NADPH – Provides electrons

What are the roles of ATP and NADPH?What are the roles of ATP and NADPH?



3. Regeneration of RuBP3. Regeneration of RuBP

The unused PGAL molecules get more ATP.The unused PGAL molecules get more ATP.

The phosphorus in ATP will change PGAL to The phosphorus in ATP will change PGAL to RuBPRuBP

The cycle is now complete. The RuBP molecules The cycle is now complete. The RuBP molecules are used at the beginning of the Calvin Cycle.are used at the beginning of the Calvin Cycle.


Summary of Calvin Summary of Calvin Cycle Cycle

Structure-FunctionStructure-FunctionRelationshipRelationship

Why chloroplasts are Why chloroplasts are biconvex shapebiconvex shape??

To increase surface area to maximise the To increase surface area to maximise the absorption of light.absorption of light.

structure and their functions structure and their functions

Why do chloroplasts contain DNA?Why do chloroplasts contain DNA?

DNA allows chloroplasts to replicate themselves.DNA allows chloroplasts to replicate themselves.

when cell divides, the new cells will receive the when cell divides, the new cells will receive the correct number of chloroplasts.correct number of chloroplasts.

VERY UNIQUE FEATURE OF VERY UNIQUE FEATURE OF CHLOROPLAST AND MITOCHONDRION CHLOROPLAST AND MITOCHONDRION


Why do chloroplasts contain Ribosomes?Why do chloroplasts contain Ribosomes?

Allows chloroplast to produce their own enzyme Allows chloroplast to produce their own enzyme for photosynthesis.for photosynthesis.

Ribosomes are found in the stroma attached to Ribosomes are found in the stroma attached to thylakoids.thylakoids.

ANOTHER UNIQUE FEATURE OF ANOTHER UNIQUE FEATURE OF CHLOROPLAST CHLOROPLAST

How are thylakoids suited for photosynthesis?How are thylakoids suited for photosynthesis?

Provides Provides large surface arealarge surface area for the attachment of for the attachment of enzymes and co-enzymes involved in the electron enzymes and co-enzymes involved in the electron transfer chain of the LDR.transfer chain of the LDR.


11

22Idea of Compartmentalisation – Allows different Idea of Compartmentalisation – Allows different enzyme-driven reactions to occur within the enzyme-driven reactions to occur within the chloroplasts simultaneously. chloroplasts simultaneously.

Why chloroplasts contain about 3000 grana?Why chloroplasts contain about 3000 grana?

This increases the surface area available for the This increases the surface area available for the attachment of chlorophyll molecules to trap more attachment of chlorophyll molecules to trap more light.light.


Why do chlorophyll not shade each other?Why do chlorophyll not shade each other?

Same answer as above. Same answer as above.

the end the end

any questions? any questions?

bio ppt chloroplast project

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