intro-hostory and discovery-characteristics of phytochrome-chemical nature of phytochrome-mode of action-mechanism-phytochrome mediated physiological responses-phytochrome is a pigment system:some evidences-role of phytochrome
intro-hostory and discovery-characteristics of phytochrome-chemical nature of phytochrome-mode of action-mechanism-phytochrome mediated physiological responses-phytochrome is a pigment system:some evidences-role of phytochrome
Everything about photoperiodism from scratch to smart, from the oldest models to the latest models as well as proposed one, exclusive and elusive illustrations and models for proper understanding
By -
Avinash Darsimbe
Assistant Professor
Department of Botany
Shri Shivaji Science College, Amravati
Physiology of Senescence and Abscission
B.Sc. III (Sem - V)
BOTANY : PLANT PHYSIOLOGY AND ECOLOGY
Sant Gadge Baba Amravati University,Amravati
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.
The Shoot apex is also known as the terminal bud of plants that grows from 0.1-1.0 mm and consists of the apical meristem, developing leaves and the immediate surrounding leaf primordial. The shoot apex is present in both dicot and monocot plants.
Everything about photoperiodism from scratch to smart, from the oldest models to the latest models as well as proposed one, exclusive and elusive illustrations and models for proper understanding
By -
Avinash Darsimbe
Assistant Professor
Department of Botany
Shri Shivaji Science College, Amravati
Physiology of Senescence and Abscission
B.Sc. III (Sem - V)
BOTANY : PLANT PHYSIOLOGY AND ECOLOGY
Sant Gadge Baba Amravati University,Amravati
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.
The Shoot apex is also known as the terminal bud of plants that grows from 0.1-1.0 mm and consists of the apical meristem, developing leaves and the immediate surrounding leaf primordial. The shoot apex is present in both dicot and monocot plants.
This presentation describes the nutrient uptake in plants. it explains the passive and active uptake of nutrient uptake. which are further explained as diffusion, facilitated diffusion, carrier proteins, channel proteins, ion exchange & contact exchange.
• Active transport is a mode of transportation in plants, which uses stored energy to move the particles against the concentration gradient. In a plant cell, it takes place in the root cells by absorbing water and minerals.
• The intake of mineral ions by the root system along the concentration gradient by diffusion without the expenditure of energy is called passive absorption.
Photosynthesis is an anabolic process by which simple inorganic substances like CO2 and H2O are converted into a complex substance like a carbohydrate in the presence of light and chlorophyll.
The origin and geological history of oxygenrita martin
Oxygen third most profusely found element in the universe Commercially, oxygen can be prepared by the process of liquefaction and fractional distillation of air and through electrolysis of water
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2. Mineral Absorption
Plants obtain minerals from soil where these are dissolved in soil or present.
Mineral salt absorption is independent of water absorption.
Maximum mineral salt absorption occurs by zone of elongation.
3. No mineral salt absorption occur by root hair zone.
Minerals salt absorption occurs directly by cells of epiblema not by root hairs.
Mineral salts are absorbed mostly in the form of ions, i.e., anions and cations.
Mechanism of Mineral absorption
Mineral salt absorption takes place by passive and active both types. To explain passive
and active absorption many theories given.
Passive absorption
Absorption of ions without the use of metabolic energy is known as passive absorption.
This is carried by purely physical forces.
Briggs and Robertson (1957) demonstrate the passive absorption of ions by root system .
They showed
I. Mineral salts are not affected by temp. and metabolic inhibitors.
II. Rapid uptake of ions occurs when the concentration is higher in outer solution than in the
cell sap of the root cells, the mineral salts are absorbed according to the concentration
gradient by simple process of diffusion.
4. Some theories explaining the mechanism of passive
absorption of minerals
• Mass Flow Theory
According to Hylmo (1953, 1955) the ion absorption
increase with increase in transpiration. The ions have
been considered to move in a mass flow with water
from the soil solution through the root and
eventually to the shoot.
5. • Ion exchange hypothesis
According to this theory absorbed ions are exchanged from the
external medium. A cation is exchanged for a cation and anion
for anion.
There are two theories to explain the mechanism of ion
exchange__
• Contact exchange theory
According to this theory, ions are not completely static, they are
always oscillating around their absorption area and when the
oscillating volume of the ions on the roots and on the colloidal
partials overlap each other, ions get exchange.
6. • Carbonic acid exchange theory
According to this theory, Co2 released by roots
during respiration reacts with water to produce
carbonic acid which dissociated into H+ ions and
bicarbonate ions.
H+ ion exchanges itself with the cations absorbed on
the colloidal particles and the bicarbonate (HCO-
3)
ions release the absorbed anions to supply both
anions and cations nearby.
7. • Donnan equilibrium
This mechanism given by F.G Donnan in 1927.
According to this mechanism there are no fixed ions
there are equal no of anions and cations on both sides
of the membrane at equilibrium.
Positive ions inside/Positive ions outside = Negative
ions outside/Negative ions inside
• Simple diffusion theory
• Facilitated diffusion hypothesis
8. Active absorption
The lipid protein membrane of a cell is largely permeable to free ion. The energy is
used to transport of such free ions across the membrane is known as active
absorption.
Energy which is used in this process comes from the metabolic activities like
respiration etc.
Mineral absorption is mainly active process. Hoagland (1944) indicated active ion
absorption and their accumulation against concentration gradient in green algae
Nitella and Valonia.
Evidences show the use of energy in the absorption of mineral salt
• Higher rate of transpiration increase the salt accumulation inside the cell
• Respiration inhibitor check the process of salt uptake
• By decrease the oxygen content in the medium the absorption also decrease
9. • Carrier concept
This concept was proposed by Vanden Honert (1937).
According to this theory the plasma membrane is
impermeable to free ions. But some compound
present in it acts as carrier and combines with ions to
form carrier-ion-complex which can move across the
membrane. On the inner surface of the membrane
this complex breaks releasing ions into the cell while
the carrier goes back to the outer surface to pick up
fresh ions.
10. Some observations support the carrier concept of
active absorption of mineral salts
(i) Isotopic Exchange
Actively absorbed radioactive ions (such as 35S04)
cannot diffuse back or be exchanged with other ions
in the outer solution indicating thereby that the
plasma membrane is not permeable to free ions.
(ii) Saturation Effects
After a limit, If we increase salts con. in outer solution
there is no increase in mineral salt absorption. It is
because the active sites on the carrier compound
become saturated with ions.
11. (iii) Specificity
Active sites on carrier compound may be specific
which can bind only some specific ions. This also
explains the selective and unequal absorption of ions
by the plants.
To explain mechanism of active salt absorption
through carrier concept there two hypothesis…..
1. Lundegardh’s Cytochrome pump theory
Lundegardh and Burstrom (1933) believed that when a plant is
transferred from water to a salt solution the rate of respiration
increases. Which is called as anion respiration or salt respiration.
The inhibition of salt respiration and the accompanying absorption of
anions by CO and cyanides,
later on led Lundegardh (1950, 54) to propose cytochrome pump theory
which is based on the following assumptions:
12. (i) The mechanism of anion and cation absorption is different.
(ii) Anions are absorbed through cytochrome chain by an active process.
(iii) Cations are absorbed passively.
According to this theory
(i) Dehydrogenase reactions on inner side of the membrane give rise to protons (H+) and
electrons (e–).
(ii) The electron travels over the cytochrome chain towards outside the membrane, so that the
Fe of the cytochrome becomes reduced (Fe++) on the outer surface and oxidised (Fe++) on
the inner surface.
(iii) On the outer surface, the reduced cytochrome is oxidised by oxygen releasing the electron
(e–) and taking an anion (A–).
(iv) The electron thus released unites with H+ and oxygen to form water.
(v) The anion (A–) travels over the cytochrome chain towards inside.
(vi) On the inner surface the oxidised cytochrome becomes reduced by taking an electron
produced through the dehydrogenase reactions, and the anion (A–) is released.
(vii) As a result of anion absorption, a cation (M+) moves passively from outside to inside to
balance the anion.
13.
14. Main defects of the above theory are
(i) It envisages active absorption of only anions.
(ii) It does not explain selective uptake of ions.
(iii) It has been found that cations also stimulate respiration.
(2) Bennet-Clark’s Protein-Lecithin Theory
In 1956, Bennet-Clark suggested that because the cell membranes chiefly consist of phos-
pholipids and proteins and certain enzymes seem to be located on them, the carrier could be a
protein associated with the phosphatide called as lecithin.
According to this theory
(i) The phosphate group in the phosphatide is regarded as the active centre binding the
cations, and the basic choline group as the anion binding centre.
(ii) The ions are liberated on the inner surface of the membrane by decomposition of the
lecithin by the enzyme lecithinase.
(iii) The regeneration of the carrier lecithin from phosphatidic acid and choline takes place in
the presence of the enzymes choline acetylase and choline esterase and ATP. The latter acts
as a source of energy.