what is photosynthesis?-history background-photosynthetic pigmment system-light harvesting complex-photo oxidation of water-photophosphorylation and mechanism of electron transport
In this ppt, you will learn about photosystem first of photosynthesis, with video and animation such a nice presentation. electron movement by animation, see and understand the system.
what is photosynthesis?-history background-photosynthetic pigmment system-light harvesting complex-photo oxidation of water-photophosphorylation and mechanism of electron transport
In this ppt, you will learn about photosystem first of photosynthesis, with video and animation such a nice presentation. electron movement by animation, see and understand the system.
Photorespiration - Introduction, why is it occur in plants, pathway of photorespiration, Enzymes names, pathway step by step explanation, Benefits of photorespiration, additional information related to photorespiration, Rubisco enzyme, Oxygenase enzyme, Oxygen concentration higher leads to photorespiration, problem to carry out calvin cycle.
Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the sun, into chemical energy that can be used to fuel the organisms' activities. Carbohydrates, such as sugars, are synthesized from carbon dioxide and water.
For this assignment, we were instructed to create a powerpoint presentation of at least 12 slides that adequately covered an academic subject of our choice. All sources for media is cited in the work cited at the end of the presentation.
Photorespiration - Introduction, why is it occur in plants, pathway of photorespiration, Enzymes names, pathway step by step explanation, Benefits of photorespiration, additional information related to photorespiration, Rubisco enzyme, Oxygenase enzyme, Oxygen concentration higher leads to photorespiration, problem to carry out calvin cycle.
Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the sun, into chemical energy that can be used to fuel the organisms' activities. Carbohydrates, such as sugars, are synthesized from carbon dioxide and water.
For this assignment, we were instructed to create a powerpoint presentation of at least 12 slides that adequately covered an academic subject of our choice. All sources for media is cited in the work cited at the end of the presentation.
Photosynthesis overview
A. Purpose
B. Location
The light vs. the “dark” reaction
Chloroplasts pigments
A. Light absorption
B. Types
Light reactions
A. Photosystems
B. Photophosphorylation
V. The light independent reaction (“dark” reaction)
A. Carbon “fixation”
B. Reduction
C. Regeneration
VI. Alternative plants
1 outline the steps involved in synthesizing AT and NADPH for use in.pdfarihantgiftgallery
1 outline the steps involved in synthesizing AT and NADPH for use in the Calvin cycle.
2 Outline the 3 phases of the Calvin Cycle.
Solution
1) STEPS INVOLVED IN SYNTHESIZING ATP AND NADPH
Synthesis of ATP and NADPH occurs during the light-dependent reactions in the first phase of
photosynthesis. The first phase of photosynthesis is to convert solar energy into chemical energy
in the form of ATP and NADPH which will be used further in the light-independent reactions
(Calvin\'s cycle). NADPH and ATP are produced from the combined work of protein complexes
and pigment molecules.
PRODUCTION OF ATP & NADPH
This process takes place in a multiprotein complex called photosystem. The thylakoid membrane
of the chloroplast consists of two photosystems. They are the, Photosystem I (P680) and
Photosystem II (P700).
PHOTOSYSTEMS
These are the structural and functional units of protein complexes that are found in the thylakoid
membranes of chloroplasts that carry out the absorption of light and trasfer of energy and
electrons during photosynthesis.
Each photosystem consists of multiple antenna proteins that contain a mixture of 300–400
chlorophyll a and b molecules, and also pigments like carotenoids.
Cytochrome b6f complex and ATP synthase are the major protein complexes in the thylakoid
membrane that work with the photosystems to create ATP and NADPH.
STEPS INVOLVED
Chlorophyll in the photosystem absorbs light energy. In PS II light energy is used to split water
into 2 electrons, 2 hydrogen atoms and one oxygen molecule.
Chlorophyll a in the reaction centre of PS II absorbs a photon which excites the electron in the
molecule to a higher level. As the state of the eletron is highly unstable, the electron is
transferred to another molecule creating a chain of reactions called Electron Transport Chain
(ETC).
Electrons flow from PS II to cytochrome b6f to PS I. During this transistion they loose energy
and has to re energized. Hence another photon is absorbed by the protein antenna and the energy
is transmitted to the PS I reaction centre known as P700 which gets oxidized and sends a high
energy electron to reduce NADP+ to NADPH and releases oxygen as a waste product.
ATP is produced by Cytochrome b6f and ATP Synthase by a process called photophospyrlation.
Two types of photophosphorylation takes place during ATP synthesis. They are
Cyclic photophosphorylation
This process involves photosystem I and P700. Energy is provided to produce a proton gradient
across the membrane that is used to power ATP synthase during chemiosmosis (movement of
ions from higher to lower concentration) which helps in the conversion of ADP to ATP. Hence
the electrons travel in a cylic manner back to the PS I, this reaction is called as cyclic
photophosphoryltaion.
Non-cyclic photophosphorylation
Photosystem I and II are used in a series in non-cyclic photophosphorylation. P680 is the
reaction centre invovled in this process and the electrons travel in a non-cyclic manner.
Photolysis .
this presentation contains briefing of the chapter as per NCERT syllabus in details that contains photosynthesis process, early experiments, photosynthetic pigments,photophosphorylation, light reactions and dark reactions n factors affecting photsynthesis.
Here we have described what photosynthesis is. We have gone through different phases of photosynthesis as well as different cycles of photosynthesis used by different plants
Photosynthesis is an inevitable process that keeps us alive.It is the main source for food and it's byproduct keeps us breathing. This ppt is the detailed explanation of photosynthesis and the components involved in it. Here you can easily understand the concept and you are able to strengthen your grip on this topic.
Human digestive system structure and function
overview
Major organs
Mouth
Esophagus
Stomach
small intestine
large intestine
Acessory organs:
Liver
gall bladder
Pancreas.
Human digestive system
Major organs
Mouth
Esophagus
Stomach
small intestine
large intestine.
Acessory organs:
Liver
Gall bladder
Pancreas.
MAJOR ORGANSThe Mouth
pH: 7
The first part of the digestive system
the entry point of food.
Structures in the mouth that aids digestion
Teeth – cut, tear, crush and grind food.
Salivary glands – produce and secrete saliva into the oral cavity.
saliva
moistens the food
contains enzymes (ptyalin or salivary amylase)
begins digestion of starch into smaller polysaccharides.
Function:
Mechanical digestion.
increasing surface area for faster chemical digestion.
The Esophagus
a tube connecting the mouth to the stomach
running through the Thoracic cavity.
Location:
lies behind windpipe (Trachea).
The trachea has as an epiglottis
preventing food from entering the windpipe,
moving the food to the esophagus while swallowing.
Food travels down the esophagus, through a series of involuntary rhythmic contractions (wave-like) called peristalsis.
Function:
The lining of the esophagus secretes mucus
lubricating
to support the movement of food.
Esophageal sphincter:
bolus reaches the stomach
must pass through a muscular ringed valve called the esophageal sphincter (Cardiac Sphincter).
Function:
prevent stomach acids from back flowing into the esophagus.
Stomach
J-shaped muscular sac
Has inner folds (rugae)
Increasing surface area of the stomach.
Function:
Stomach performs mechanical digestion
HOW By churning the bolus and mixing it with the gastric juices
secreted by the lining of the stomach.
GASTRIC JUICES HCl, salts, enzymes, water and mucus)
HCL helps break down of food and kills bacteria that came along with the food.
The bolus is now called Chyme.
Enzymes in stomach:
Acidic environment
HCl secreation
kill any microbes that are found in the bolus,
creating a pH of 2.
Mucus prevents the stomach from digesting itself.
Pepsin secreation
responsible for initiating the breakdown of proteins (in )food.
hydrolyzes proteins to yield polypeptides.
pH is 2, the enzyme from the salivary glands stops breaking down carbohydrates.
Pyloric sphincter:
chyme moves from the stomach to the small intestine.
It passes through a muscular ringed sphincter called the pyloric sphincter.
stomach does not digest itselfWhy ?
Protective Mechanism:
three protective mechanisms.
First the stomach only secretes small amounts of gastric juices until food is present.
Second the secretion of mucus coats the lining of the stomach protecting it from the gastric juices.
The third mechanism is the digestive enzyme pepsin is secreted in an inactive protein c
Biology I Presentation
FUNGI
We will learn
General characteristics of fungi
Structure of fungi
Economic Importance
Pathogenicity
Brief intro of some fungi
THE SIX KINGDOMS
Fungi are placed in a separate kingdom called the kingdom fungi
OF FUNGI
CHARACTERISTICS
The Characteristics of Fungi
Fungi are NOT plants
Nonphotosynthetic
Eukaryotes
Nonmotile
Most are saprobes (live on dead organisms)
The Characteristics of Fungi
Absorptive heterotrophs (digest food first & then absorb it into their bodies
Release digestive enzymes to break down organic material or their host
Store food energy as glycogen
The Characteristics of Fungi
Important decomposers & recyclers of nutrients in the environment
Most are multicellular, except unicellular yeast
Lack true roots, stems or leaves
fungi as a decomposers
The Characteristics of Fungi
Cell walls are made of chitin (complex polysaccharide)
Body is called the Thallus
Grow as microscopic tubes or filaments called hyphae
The Characteristics of Fungi
Some fungi are internal or external parasites
A few fungi act like predators & capture prey like roundworms
The Characteristics of Fungi
Some are edible, while others are poisonous
The Characteristics of Fungi
Produce both sexual and asexual spores
Classified by their sexual reproductive structures
The Characteristics of Fungi
Grow best in warm, moist environments
Mycology is the study of fungi
Mycologists study fungi
A fungicide is a chemical used to kill fungi
The Characteristics of Fungi
Fungi include puffballs, yeasts, mushrooms, toadstools, rusts, smuts, ringworm, and molds
The antibiotic penicillin is made by the Penicillium mold
FUNGI SIZE
NON-REPRODUCTIVE
Vegetative Structures
Hyphae
Tubular shape
ONE continuous cell
Filled with cytoplasm & nuclei
Multinucleate
Hard cell wall of chitin also in insect exoskeletons
Hyphae
Stolons – horizontal hyphae that connect groups of hyphae to each other
Rhizoids – rootlike parts of hyphae that anchor the fungus
Hyphae
Cross-walls called SEPTA may form compartments
Septa have pores for movement of cytoplasm
Form network called mycelia that run through the thallus (body)
Absorptive Heterotroph
Fungi get carbon from organic sources
Tips of Hyphae release enzymes
Enzymatic breakdown of substrate
Products diffuse back into hyphae
Modifications of hyphae
Fungi may be classified based on cell division (with or without cytokinesis)
Aseptate or coenocytic (without septa)
Septate (with septa)
Modifications of hyphae
Hyphal growth
Hyphae grow from their tips
Mycelium is an extensive, feeding web of hyphae
Mycelia are the ecologically active bodies of fungi
ASEXUAL & SEXUAL SPORES
REPRODUCTIVE STRUCTURES
REPRODUCTION
Most fungi reproduce Asexually and Sexually by spores
ASEXUAL reproduction is most common method & produces genetically identical organisms
Fungi reproduce SEXUALLY when conditions are poor & nutrients
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
2. OUTLINE :
Overview of mechanism of photosynthesis
Pigments
Process of photosynthesis
Phosphorylation
Photosystems
Dark reaction
C4 and CAM pathway
3. OVERVIEW OF PHOTOSYNTHESIS
A process by which autotrophic organisms use
light energy to make sugar & oxygen gas from
carbon dioxide & water.
Occurs in chloroplast, an organelle in mesophyll
4. MECHANISM OF
PHOTOSYNTHESIS Divided into 2 phases :
Light reaction
a) photolysis of water
b)phosphorylation
Dark reaction (carbon fixation or calvin cycle)
Light reaction is light dependent & takes place in
grana of chloroplast & its product is NADPH & ATP.
Dark reaction is light independent & occurs in
stroma of chloroplast.
5. FOUR PHASES OF
PHOTOSYNTHESIS 1) light absorption & energy delivery by antenna
systems
2) primary electron transfer in reaction centers
3) energy stabilization by secondary processes
4)synthesis & export of stable products
First 3 phases makeup the light reaction & fourth
encompasses the dark reaction.
6. PIGMENTS Substances that have ability to absorb specific
wavelengths of light & reflect all others.
Pigments are colored.
Easily excited by light energy.
The color we see is the net effect of all the light
reflecting back at us…!
photosynthetic pigments are of 3 types
1)Chlorohylls (chlorophyll a & b)
2)Accessory photosynthetic pigment or carotenoids
(carotene & xanthophyll)
3) phycobilins
7. CHLOROPHYLL A
Most important pigment in photosynthesis.
Absorbs blue,red & violet wavelengths in the visible
spectrum.
Formula is C55H72O5N4Mg
Complex ring structure having 2 parts i.e. head & tail
Head(porphyrin ring) : 4 complex pyrole rings of carbon
& nitrogen.
In the centre of porphyrin ring a single magnesium atom
is attached to the nitrogen of each pyrrole ring.
Maximum absorption by chlorophyll a occurs in blue &
red regions.
Tail is attached to one of the pyrrole rings.
It is a long hydrocarbon phytol (C20H39) & anchors
chlorophyll molecule in thylakoid membrane.
9. CHLOROPHYLL B
Its structure is similar to chlorophyll a but CH3 is
replaced by CHO.
So molecular formula is C55H70O6N4Mg
It primarily absorbs blue light .
It is used to complement absorption spectrum of a
by extending the range of light wavelengths a
photosynthetic organism is able to absorb.
10. ACCESSORY PIGMENTS
They are not directly involved in LDR .
includes carotenes & xanthophylls.
carotenes are hydrocrbons with general molecular
formula C40H56
They absorb wavelengths that are not efficiently
absorbed by chloropyhlls .
Carotenoid is yellow to orange in color
Xanthophyll is yellow in color.
Carotenoids have 2 important roles in plants
1)transfer the light energy they capture to
chlorophyll to use in the LDR.
2)Protect chlorophyll a from photo-oxidation
12. PROCESS :
Photosynthesis occur in two phases :
Phase 1 : Light reaction ( granna -thalakoid
membrane )
Phase 2 : Dark reaction( stroma)
Reaction
6 CO2 + 6 H2O sunlight C6 H12 O6 + 6 O2
carbon dioxide + water = glucose(sugar ) + oxygen
13. PHASE 1.LIGHT REACTION
Also called Light Dependent Reaction which contain Photosystem I
and Photosystem II.
Occurance: chloroplast (granna - thylakoid)
Chlorophyll (thylakoid) traps energy from light
Requirement light ,water
NADP + ADP + Pi
Products O2 ATP & NADPH
Two steps
Energy is Capture from Sunlight.
light energy, trapped by chlorophyll, is used
Step 1 photolysis of water
Water is Split into Hydrogen Ions ,electron and Oxygen (O2).
The O2 Diffuses out of the Chloroplasts (Byproduct).
Formation of reduced NADPH ( chemical energy )
Step 2 phosphorylation
The Light Energy is Converted to Chemical Energy, which is Temporarily Stored
in ATP (ADP + Pi + energy )
14. PHASE 2. DARK REACTION
Other names :
Calvin Cycle
Light Independent Reaction
Carbon Fixation or C3 Fixation
Does not require light
Location Occurs in stroma of chloroplast
Requirments
ATP and NADPH as a fuel
CO2 (air )
Product glucose sugar
Step
CO2 fixation in glucose sugar
The Chemical Energy Stored in
ATP and NADPH powers the
formation of Organic Compound
glucose (Sugar) using CO2
18. DEFINITION
In the process of photosynthesis, the phosphorylation
of ADP to ATP using the energy of sunlight is called
photophosphorylation.
In photophosphorylation, light energy is used to create
a high-energy electron donor and a lower energy
electron acceptor. Electrons then move spontaneously
from donor to acceptor through an electron transport
chain.
TYPES OF PHOTOPHOSPHORYLATION
There are two types of photophosphorylation
1.Cyclic photophosphorylation
2.Non-cyclic photophosphorylation
19. CYCLIC
PHOTOPHOSPHORYLATION
In bacterial photosynthesis, a single photosystem is
involved.
When an electron is energized by absorption of light, it is
ejected from the photosystem reaction centre.
The electron then passes down through an electron
transport system, and finally to the reaction centre.
The energy released during this electron transport is used
to produce ATP.
Since the excited electron returns to the reaction centre,
this mechanism for making ATP is called cyclic
photophosphorylation.
No reducing power needed for biosynthesis generated in
this process
21. NON-CYCLIC
PHOTOPHOSPHORYLATION
Plants and cyanobacteria utilize two photosystems
which work sequentially to produce both energy and
reducing power.
First, a photon of light ejects a high electron from
photosystem II.
The electron lost from photosystem II does not return
to photosystem II, but is replaced by an electron
generated from the enzymatic splitting of water and
the release of oxygen.
22. The electron then travels from the excited reaction
centre of photosystem II down an electron transport
chain and finally to the reaction centre of photosystem
I.
This transport system generates a photon motive force
that is used to produce ATP.
Since the excited electron does not return to
photosystem II, this mechanism for making ATP is
called non-cyclic photophosphorylation.
25. INTRODUCTION
Photosystems are involved in light reaction
Photosystems are functional and structural units of protein complexes
involved present in thalykoid membrane of GRANUM.
Both photosystems work together.
Together carry out the primary photochemistry of photosynthesis: the
absorption of light and the transfer of energy and electrons.
They are found in the thylakoid membranes of plants, algae and
cyanobacteria (in plants and algae these are located in the chloroplasts),
or in the cytoplasmic membrane of photosynthetic bacteria.
There are two kinds of photosystems: II and I.
The flow of electrons occurs in two ways
---Non-Cyclic Pthway: passes through both photosystems (Z-
scheme)
---Cyclic Pathway : occurs only in PSI.
26. Each photosystem consists of
two parts:
Antenna Complex :
Cluster of Chlorophyll
a,b and carotenoid
molecules which gather
light ad transfer it to
reaction centre.
Reaction Centre: Has
chlorophyll "a" molecules
slightly slightly
different from other
chlorophyll molecules.
27. PHOTOSYSTEM II
Absorbs light of 700nm
Water splits, electrons enter PSII reaction centre.
When P680 gains energy, 2 electrons become excited and
leave the molecule.
The electrons are readily captured by primary electron
acceptor
Primary electron acceptor>> Plastoquinone>>Cyt b>>Cyt f>>
Plastocyanine
PHOTOPHOSPHORYLATION:
As the electron pass through the electron trasport chain its
energy is released and is used by thylakoid membrane to
synthesize ATP.
28. PHOTOSYSTEM I (P680)
Absorbs light of 680nm
The electrons from photosystem II finally
reaches the reaction centre of photosystem I.
Then electrons move to the primary electron
acceptor.
From here they pass to Ferrodoxin (Fd).
The elctrons then passes from Ferrodoxin to
NADP,taking H+ and form NADPH2.
30. OVERALL RESULT OF Z-SCHEME.
The result of the non-cyclic electron flow is that water is oxidzed
yielding H+,e- and O2.
ATP is produced.
NADP+ becomes NADPH2.
The hydrogen and Energy of NADPH2 and ATP produced in the light
reaction are used in dark reaction.
32. the free energy of cleavage of ~P bonds of ATP,
and reducing power of NADPH, are used to fix
and reduce CO2 to form carbohydrate.
Carbon atoms from CO2 are bonded, or fixed,
into organic compounds = carbon fixation.
THIS OCCURS IN THE STROMA
33.
34. An enzyme (rubisco),
combines CO2 with a 5-
carbon sugar RuBP
The product, 6-C
sugar, immediately
splits into
2, -3C molecules
(PGA)
PGA–
Phosphoglyceric
Acid
35. PGA is converted to
another 3- Carbon
molecule PGAL in a 2
part process:
Each PGA receives a
P group from ATP
The resulting
compound receives a
proton from
NADPH and
releases the P,
producing PGAL
( ADP & NADP+
return to light rxn., to
make ATP and
NADPH)
36. Most of the PGAL
is converted back to
RuBP
Requires a P
from another
ATP
Some PGAL leave
and used by plants
create organic
compounds
37. BALANCE SHEET FOR PHOTOSYNTHESIS
How much ATP & NADH are required to make 1 molecule
of PGA from carbon dioxide?
Each turn fixes one CO2
PGAL is a 3-C molecule (takes 3 turns to make each
molecule)
Each turn of the cycle:
3 ATP ( 2 in step 2 & 1 in step 3)
2 NADPH (step 3)
39. C4 PLANT OR PHOTOSYNTHESIS
What is C4 plant or photosynthesis ?
Present particularly in monocot
Presence of Kranz anatomy
PEP is the initial acceptor
First product is OAA ( 4 carbon compound /
acid)
Oxygen does not inhibit this process
40. C4 (CONT.)
Photorespiration is low
Rate of transpiration is low
No wastage of carbon dioxide
Well adapted in xeric condition
Distinct division of labour
Requires more ATP than C3
41. CAM PATHWAY
It is an adaptation of plants in arid condition
CAM plants use both C3 and C4 pathways
CAM plants use only mesophyll cells
Stomata are close during the day
Prevents carbon dioxide entrance as well while
preventing water loss
Stomata opens at night in cooler temprature
42. CAM PATHWAY (CONT.)
Carbon dioxide diffuses
Carbon dioxide combines with PEP forming OAA
OAA reduce to form Malate
Malate stored in vacuoles
Photosynthesis commences during the day
Transport of malate to cytoplasm
43. CAM PATHWAY(CONT.)
Formation of pyruvate
Entrance of carbon dioxide to chloroplast
Formation of starch
Example :
Fleshy succulants (stone crops )
ferns