Cellular respiration includes both aerobic and anaerobic respiration. Aerobic respiration fully oxidizes glucose or other fuels and generates the most ATP. It involves glycolysis, the citric acid cycle, and the electron transport chain which uses oxygen as the final electron acceptor. During these processes, energy released is used to synthesize ATP through substrate-level phosphorylation and oxidative phosphorylation. Anaerobic respiration utilizes other molecules besides oxygen as electron acceptors, and fermentation generates only a small amount of ATP without using the electron transport chain.
Mitochondria are membrane-bound cell organelles (mitochondrion, singular), known as the power house of the cell that generate most of the chemical energy needed to power the cell's biochemical reactions. Mitochondria generates most of the cell's supply of adenosine triphosphate (ATP), by a process called
“oxidative phosphorylation”.
This presentation gives an overview of Lipid Rafts, how it was discovered, its importance and the future research in this area,Feel free to comment and ask any questions
Citric acid cycle krebs cycle or tricarboxylic acidhimanshupaneru1
Krebs cycle/ citric acid cycle/ tricarboxylic acid cycle TCA is the important topic from metabolism of carbohydrate in which we disscuss about cirtic acid cycle introduction, steps, regulation, energetics, important terms and lot more.
Mitochondria are membrane-bound cell organelles (mitochondrion, singular), known as the power house of the cell that generate most of the chemical energy needed to power the cell's biochemical reactions. Mitochondria generates most of the cell's supply of adenosine triphosphate (ATP), by a process called
“oxidative phosphorylation”.
This presentation gives an overview of Lipid Rafts, how it was discovered, its importance and the future research in this area,Feel free to comment and ask any questions
Citric acid cycle krebs cycle or tricarboxylic acidhimanshupaneru1
Krebs cycle/ citric acid cycle/ tricarboxylic acid cycle TCA is the important topic from metabolism of carbohydrate in which we disscuss about cirtic acid cycle introduction, steps, regulation, energetics, important terms and lot more.
Photophosphorylation/Photosynthesis/Light reactionM. Adnan Qadar
This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors.
References
1. Taiz & Zeiger
2. Salisbury author
This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors.
Photophosphorylation/Photosynthesis/Light reactionM. Adnan Qadar
This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors.
References
1. Taiz & Zeiger
2. Salisbury author
This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors. This ppt contain an easy understanding guide for teachers and students. All the contents are reviewed and edited by senior professors.
Biological oxidation and Electron Transport Chain is the most important and confusing topic in biochemistry metabolism, but here we tried to put it in the simplest way easy to learn. This presentation was guided by Dr. Arpita Patel and made by Miss Nidhi Argade.
Informative Website
we are from san antonio senior highschool and we will teach you about the different process that you'll surely understand
https;//edmarnewsome.wixsite.com/mysite
Conclusion Phases of Oxidative Phosphorylation Focus your attention.pdfebrahimbadushata00
Conclusion: Phases of Oxidative Phosphorylation Focus your attention on the two phases of
oxidative phosphorylation in Focus Figure 24.8. Sort the events into the appropriate phase of
oxidative phosphorylation. Events may be sorted to only one bin.
Solution
Oxidative phosphorylation is the process where energy is harnessed through a series of protein
complexes embedded in the inner membrane of mitochondria to create ATP.
NADH donates e-During breakdown of glucose ,a large amount of NADH and FADH2 are
produced in glycolysis and citric acid cycle
NADH transfers transfers its high energy molecules to protein complex1 and causes loss of
electrons
NADH -> NAD++H++2e-
Generation of protongradient
The process of transferring of electrons drives the pumping of protons and it generates proton
gradient across the inner mitochondrial membrane
Transfer of electrons
Electrons transfers between specalized proteins embedded in the inner mitochondrial membrane.
Generation of Water
At the end of the electron transport chain ,electrons are transferred to molecular oxygen,which
splits in half and takes up H+ to form water
1/2O2+2H++2e-->H2O
Synthesis of ATP
This proton pumping that is ultimately responsible for coupling the oxidation and reduction
reaction to ATP synthesis from ADP and HPO42-.Phosphorylation of ADP and synthesis of ATP
occurs
Oxygen is the final electronacceptor Electrons move from one carrier to another and finally
transferred to o2
Chemiosmosis
The diffusion of hydrogen ions across the membrane via ATP synthase due to proton gradient
that forms on the otherside of the membrane
Flow of proton intomitochondrial martrix
ATP synthetase allows H+ to diffuse back into matrix
Phosphorylation of ADP
ATP synthetase allows H+ ions to diffuse back into the matrix and uses the free energy released
to synthesize ATP from ADP and HPO42-
Oxidation of food fuels
To make ATP,energy must be obsorbed it is supplied by the food we eat.One of the principal
energy yielding nutrients in our diet is glucose.The complete breakdown of glucose into CO2
occurs in two process glycolysis and citric acid cyclePhase 1Phase2Neither
NADH donates e-During breakdown of glucose ,a large amount of NADH and FADH2 are
produced in glycolysis and citric acid cycle
NADH transfers transfers its high energy molecules to protein complex1 and causes loss of
electrons
NADH -> NAD++H++2e-
Generation of protongradient
The process of transferring of electrons drives the pumping of protons and it generates proton
gradient across the inner mitochondrial membrane
Transfer of electrons
Electrons transfers between specalized proteins embedded in the inner mitochondrial membrane.
Generation of Water
At the end of the electron transport chain ,electrons are transferred to molecular oxygen,which
splits in half and takes up H+ to form water
1/2O2+2H++2e-->H2O
Synthesis of ATP
This proton pumping that is ultimately responsible for coupling the oxidation and reduction
reaction to ATP synthesis from ADP .
ETC and Phosphorylation by Salman SaeedSalman Saeed
ETC and Phosphorylation lecture for Biology, Botany, Zoology, and Chemistry Students by Salman Saeed lecturer Botany University College of Management and Sciences Khanewal, Pakistan.
About Author: Salman Saeed
Qualification: M.SC (Botany), M. Phil (Biotechnology) from BZU Multan.
M. Ed & B. Ed from GCU Faisalabad, Pakistan.
The electron transport chain is comprised of a series of enzymatic reactions within the inner membrane of the mitochondria, which are cell organelles that release and store energy for all physiological needs.
As electrons are passed through the chain by a series of oxidation-reduction reactions, energy is released, creating a gradient of hydrogen ions, or protons, across the membrane. The proton gradient provides energy to make ATP, which is used in oxidative phosphorylation.
Bioethanol production from cheese whey.pptxAsmamawTesfaw1
It deals about production of bioethanol from cheese whey which is not sterilized and other characters of the ethanol producing yeasts were also covered
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
2. 7.1. Cellular respiration
Cellular respiration includes both
aerobic and anaerobic respiration but is
often used to refer to aerobic respiration
Although carbohydrates, fats, and
proteins are all consumed as fuel, it is
helpful to trace cellular respiration with
the sugar glucose
C6H12O6 + 6 O2 6 CO2 + 6 H2O +
Energy (ATP + heat)
2
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7. The electron donor is called the
reducing agent
The electron receptor is called the
oxidizing agent
Some redox reactions do not transfer
electrons but change the electron
sharing in covalent bonds
An example is the reaction between
methane and O2
7
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9. 7.1.1. Source of high energy
Energy for living things comes from food.
Originally, the energy in food comes from
the A) sun photosynthesis Eg plant,
algae cyanobacteria.
B) redox chemoautotroph Eg bacteria)
All energy is stored in the bonds of
compounds—breaking the bond releases
the energy
When the cell has energy available it can
store this energy by adding a phosphate
group to ADP, producing ATP
9
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14. 14
Formation of ATP
ATP can be formed by three different
mechanisms:
1. Substrate-level phosphorylation –
transfer of phosphate group from a
phosphorylated compound (substrate)
directly to ADP
2. Oxidative phosphorylation – series of
redox reactions occurring during
respiratory pathway
3. Photophosphorylation – ATP is formed
11/16/2022
15. 7.1.2. Glycolysis: Embden-
Meyerhoff
Glycolytic
Cytoplasm
Anaerobic
End products
◦ 2 Pyruvic acids
◦ 4-2 = 2 net ATP by substrate
level phosphorylation
◦ 2 NADH
◦ 2 H2O
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22. 7.1.3.Citric acid cycle
The citric acid cycle has eight steps, each
catalyzed by a specific enzyme
The acetyl group of acetyl CoA joins the cycle
by combining with oxaloacetate, forming citrate
The next seven steps decompose the citrate
back to oxaloacetate, making the process a
cycle
22
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26. The Isocitrate Dehydrogenase
Reaction (Step #3)
Oxidation of the alcohol to ketone involves the
transfer of a hydride from the C-H of the alcohol to
the nicotinamide cofactor – 3 step mechanism
26
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34. Krebs Cycle Metabolites
For every AcetylCoA
◦ 2 CO2
◦ 3 NADH
◦ 1 FADH2
◦ 1 ATP (substrate level phosphorylation
from GTP)
Regenerates
◦ CoA
◦ Oxaloacetic acid
34
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35. Role of the Citric Acid Cycle in
Anabolism
35
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36. 7.1.4. Electron transport
system
1. Oxidation–reduction enzymes
(proteins)
NADH dehydrogenases,
flavoproteins,
iron–sulfur proteins
cytochromes
2. Nonprotein electron carriers
quinones
36
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37. COMPLEX I
1. NADH (nicotinamide adenine dinucleotide
reduced form) is oxidized to NAD+, reducing
FMN (flavin mononucleotide) to FMNH2 in
one two-electron site
2. The next electron carrier is a Fe-S cluster,
which can only accept one electron at a time
to reduce the ferric ion into a ferrous ion.
3. Conveniently, FMNH2 can only be oxidized
in two one-electron steps, through a
semiquinone intermediate.
37
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38. COMPEX I contd.
4. The electron thus travels from the FMNH2
to the Fe-S cluster, then from the Fe-S
cluster to the oxidized Q to give the free-
radical (semiquinone) form of Q.
5. This happens again to reduce the
semiquinone form to the ubiquinol form,
QH2. During this process, four protons are
translocated across the inner
mitochondrial membrane, from the matrix
to the intermembrane space
6. This creates a proton gradient that will be
later used to generate ATP through
oxidative phosphorylation.
38
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39. COMPLEX II
Complex II (succinate dehydrogenase) is
not a proton pump. It serves to funnel
additional electrons into the quinone pool (Q)
by removing electrons from succinate and
transferring them (via FAD) to Q.
Other electron donors (e.g. fatty acids and
glycerol 3-phosphate) also funnel electrons
into Q (via FAD), again without producing a
proton gradient.
39
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40. COMPLEX III
Complex III (cytochrome bc1 complex)
removes in a stepwise fashion two electrons
from QH2 and transfers them to two molecules
of cytochrome c, a water-soluble electron
carrier located on the outer surface of the
membrane.
At the same time, it moves four protons across
the membrane, producing a proton gradient.
When electron transfer is hindered (by a high
membrane potential, point mutations or
respiratory inhibitors such as antimycin A),
Complex III may leak electrons to oxygen
resulting in the formation of a superoxide. 40
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41. COMPLEX IV
Complex IV (cytochrome c oxidase)
removes four electrons from four
molecules of cytochrome c and transfers
them to molecular oxygen (O2),
producing two molecules of water (H2O).
At the same time, it moves four protons
across the membrane, producing a
proton gradient.
41
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43. 7.1.5. The chemoosmosis model
and oxidation phosphorylation
Chemiosmosis – as the electron
transport carriers shuttle electrons, they
actively pump hydrogen ions (protons)
across the membrane setting up a
gradient of hydrogen ions - proton
motive force.
Hydrogen ions diffuse back through the
ATP synthase complex causing it to
rotate, causing a 3-dimensional change
resulting in the production of ATP.
43
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44. As electrons flow through complexes of ETC, protons are
translocated from matrix into the intermembrane space.
The free energy stored in the proton concentration
gradient is tapped as protons reenter the matrix via ATP
synthase.
As result ATP is formed from ADP and P . 44
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45. Electrons of NADH or FADH2 are used to reduce
molecular oxygen to water.
A large amount of free energy is liberated.
The electrons from NADH and FADH2 are not
transported directly to O2 but are transferred
through series of electron carriers that undergo
reversible reduction and oxidation. 45
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46. The flow of electrons through carriers leads to the
pumping of protons out of the mitochondrial matrix.
The resulting
distribution of
protons
generates a pH
gradient and a
transmembrane
electrical
potential that
creates a
protonmotive
force.
46
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47. ATP is synthesized when protons flow back to the
mitochondrial matrix through an enzyme complex
ATP synthase.
The oxidation of fuels and the phosphorylation
of ADP are coupled by a proton gradient across
the inner mitochondrial membrane.
Oxidative
phosphorylation is
the process in which
ATP is formed as a
result of the transfer
of electrons from
NADH or FADH2 to O2
by a series of
electron carriers.
47
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49. How Are the Electrons of Cytosolic NADH
Fed into Electron Transport?
Most NADH used in electron transport is
produced in mitochondrial matrix
Cytosolic NADH produced in glycolysis doesn't
cross the inner mitochondrial membrane
"Shuttle systems" effect electron movement
without actually carrying NADH
1. Glycerophosphate shuttle stores electrons in glycerol-
3-P, which transfers electrons to FAD
2. Malate-aspartate shuttle uses malate to carry electrons
across the membrane
49
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52. 7.1.6. Anaerobic respiration
path way
Anaerobic Respiration
Functions like aerobic respiration except
it utilizes oxygen containing ions or
others, rather than free oxygen, as the
final electron acceptor in MICROBES
◦ Nitrate (NO3
-
) and nitrite (NO2
-
)
Most obligate anaerobes use the H+
generated during glycolysis and TCA to
reduce some compound other than O2.
52
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53. 53
Fermentation
Incomplete oxidation of glucose or other
carbohydrates in the absence of oxygen
Uses organic compounds as terminal
electron acceptors
Yields a small amount of ATP
Production of ethyl alcohol by yeasts acting
on glucose
Formation of acid, gas and other products by
the action of various bacteria on pyruvic acid
11/16/2022
54. Glucose
2 Pyruvate
2 NAD+
2 NADH
2 ADP 2 ATP
2 Ethanol 2 Acetylaldehyde
2 CO2
Alcohol Fermentation in Yeast
54
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55. Glucose
2 Pyruvate
2 NAD+
2 NADH
2 ADP 2 ATP
2 Lactate
Pyruvate accepts
electrons from NADH
Lactic Acid Fermentation in Humans
55
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57. FATTY ACIDS OXIDATION
A fatty acid contains a long hydrocarbon chain and
a terminal carboxylate group. The hydrocarbon
chain may be saturated (with no double bond) or
may be unsaturated (containing double bond).
57
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58. FUNCTIONS OF FATTY
ACIDS
Fatty acids have four major physiological roles.
1) Fatty acids are building blocks of
phospholipids and glycolipids.
2) Many proteins are modified by the covalent
attachment of fatty acids, which target them to
membrane locations
3) Fatty acids are fuel molecules. They are stored
as triacylglycerols. Fatty acids mobilized from
triacylglycerols are oxidized to meet the energy
needs of a cell or organism.
4) Fatty acid derivatives serve as hormones and
intracellular messengers e.g. steroids, sex
hormones and prostaglandins.
58
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59. TRIGLYCERIDES
Triglycerides are a highly
concentrated stores of energy
because they
are reduced and anhydrous.
The yield from the complete oxidation
of fatty acids is about 9 kcal g-1 (38 kJ
g-1)
Triacylglycerols are nonpolar, and are
stored in a nearly anhydrous form,
whereas much more polar proteins
and carbohydrates are more highly 59
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60. TRIGLYCERIDES V/S GLYCOGEN
A gram of nearly anhydrous fat stores
more than six times as much energy
as a gram of hydrated glycogen, which
is likely the reason that triacylglycerols
rather than glycogen were selected in
evolution as the major energy reservoir.
The glycogen and glucose stores provide
enough energy to sustain biological
function for about 24 hours, whereas the
Triacylglycerol stores allow survival
for several weeks.
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61. PROVISION OF FATTY ACIDS
FROM ADIPOSE TISSUE
The triacylglycerols are degraded to fatty acids and glycerol by hormone
sensitive lipase.The released fatty are transported to the energy-requiring
tissues.
61
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62. TRANSPORTATION OF
FREE FATTY ACIDS
Free fatty acids—also called unesterified (UFA) or
nonesterified (NEFA) fatty acids—are fatty acids
that are in the unesterified state.
In plasma, longer-chain FFA are combined
with albumin, and in the cell they are attached to
a fatty acid-binding protein.
Shorter-chain fatty acids are more water-
soluble and exist as the un-ionized acid or as a
fatty acid anion.
By these means, free fatty acids are made
accessible as a fuel in other tissues.
62
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63. TYPES OF FATTY ACID
OXIDATION
Fatty acids can be oxidized by-
1) Beta oxidation- Major mechanism, occurs in the
mitochondria matrix. 2-C units are released as
acetyl CoA per cycle.
2) Alpha oxidation- Predominantly takes place in
brain and liver, one carbon is lost in the form of
CO2 per cycle.
3) Omega oxidation- Minor mechanism, but
becomes important in conditions of impaired beta
oxidation
4) Peroxisomal oxidation- Mainly for the trimming
of very long chain fatty acids.
63
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64. BETA OXIDATION
Overview of beta oxidation
A saturated acyl Co A is degraded by a
recurring sequence of four reactions:
1) Oxidation by flavin adenine
dinucleotide (FAD)
2) Hydration,
3) Oxidation by NAD+, and
4) Thiolysis by Co ASH
64
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65. BETA OXIDATION
The fatty acyl chain is shortened by
two carbon atoms as a result of these
reactions,
FADH2, NADH, and acetyl Co A are
generated.
Because oxidation is on the β carbon
and the chain is broken between the α
(2)- and β (3)-carbon atoms—hence
the name – β oxidation .
65
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66. ACTIVATION OF FATTY
ACIDS
Fatty acids must first be converted to an active
intermediate before they can be catabolized. This
is the only step in the complete degradation of a
fatty acid that requires energy from ATP. The
activation of a fatty acid is accomplished in
two steps-
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67. STEPS OF BETA OXIDATION
Step-1
Dehydrogenation-
The first step is the
removal of two
hydrogen atoms from
the 2(α)- and 3(β)-
carbon atoms,
catalyzed by acyl-
CoA
dehydrogenase and
requiring FAD. This
results in the
formation of Δ2-trans-
enoyl-CoA and
67
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68. STEPS OF BETA
OXIDATION
Electrons from the FADH2 prosthetic group of
the reduced acyl CoA dehydrogenase are
transferred to electron-
transferring flavoprotein (ETF).
ETF donates electrons to ETF: ubiquinone
reductase, an iron-sulfur protein.
Ubiquinone is thereby reduced to ubiquinol,
which delivers its high-potential electrons to the
second proton-pumping site of the respiratory
chain.
68
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69. STEPS OF BETA
OXIDATION
Step-2- Hydration
Water is added to
saturate the
double bond and
form 3-
hydroxyacyl-CoA,
catalyzed by Δ 2-
enoyl-CoA
hydratase.
69
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70. STEPS OF BETA
OXIDATION
Step-3-
dehydrogenation-
The 3-hydroxy derivative
undergoes further
dehydrogenation on the
3-carbon catalyzed by
L(+)-3-hydroxyacyl-
CoA dehydrogenase to
form the corresponding
3-ketoacyl-CoA
compound. In this case,
NAD+ is the coenzyme
involved. 70
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72. STEPS OF BETA
OXIDATION
The acyl-CoA
formed in the
cleavage reaction
reenters the
oxidative pathway
at reaction 2.
Since acetyl-
CoA can be
oxidized to
CO2 and water via
the citric acid
cycle the
complete
oxidation of fatty
acids is achieved
72
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74. BETA OXIDATION- ENERGY
YIELD
Energy yield by the complete oxidation of one
mol of Palmitic acid-
The degradation of palmitoyl CoA (C16-acyl Co A)
requires seven reaction cycles. In the seventh cycle,
the C4-ketoacyl CoA is thiolyzed to two molecules of
acetyl CoA.
106 (129 As per old concept) ATP are produced
by the complete oxidation of one mol of Palmitic
acid. 74
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75. MINOR PATHWAYS OF
FATTY ACID OXIDATION
1) α- Oxidation- Oxidation occurs at C-2 instead
of C-3 , as in β oxidation
2) ω- Oxidation – Oxidation occurs at the
methyl end of the fatty acid molecule.
3) Peroxisomal fatty acid oxidation- Occurs for
the chain shortening of very long chain fatty
acids.
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76. α- OXIDATION OF FATTY ACIDS
Takes place in the microsomes of brain and
liver,
Involves decarboxylation process for the removal
of single carbon atom at one time with the resultant
production of an odd chain fatty acid that can be
subsequently oxidized by beta oxidation for energy
production.
It is strictly an aerobic process.
No prior activation of the fatty acid is required.
The process involves hydroxylation of the alpha
carbon with a specific α-hydroxylase that requires
Fe++ and vitamin C/FH4 as cofactors.
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77. Phytanic acid
is oxidized by
Phytanic acid
α oxidase (α-
hydroxylase
enzyme) to
yield CO2 and
odd chain fatty
acid Pristanic
acid that can
be
subsequently
oxidized by
beta oxidation.
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78. 7.2.Photosynthesis
An anabolic, endergonic, carbon dioxide
(CO2) requiring process that uses light energy
(photons) and water (H2O) to produce organic
macromolecules (glucose).
6CO2 + 6H2O C6H12O6 + 6O2
glucose
SUN
photons
11/16/2022 78
80. Chloroplasts
Structure is very similar to mitochondria
◦ Probably evolved from a cyanobacterium
incorporated into a non-photosynthetic
eukaryote (symbiosis)
In eukaryotes, the light reaction occurs in
thylakoid membrane
In prokaryotes, the light reaction occurs in:
◦ Inner (plasma) membrane
◦ In “chromatophores”
Invaginations of inner membrane
In eukaryotes, the dark reaction occurs in the
stroma
11/16/2022 80
83. Chlorophyll Molecules
Located in the thylakoid membranes.
Chlorophyll have Mg+ in the center.
Chlorophyll pigments harvest energy
(photons) by absorbing certain wavelengths
(blue-420 nm and red-660 nm are most
important).
Plants are green because the green
wavelength is reflected, not absorbed.
11/16/2022 83
84. Wavelength of Light (nm)
400 500 600 700
Short wave Long wave
(more energy) (less energy)
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86. Fall Colors
In addition to the chlorophyll pigments, there are
other pigments present.
During the fall, the green chlorophyll pigments
are greatly reduced revealing the other
pigments.
Carotenoids are pigments that are either red or
yellow.
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87. Redox Reaction
The transfer of one or more electrons
from one reactant to another.
Two types:
1. Oxidation
2. Reduction
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88. Oxidation Reaction
The loss of electrons from a substance.
Or the gain of oxygen.
glucose
6CO2 + 6H2O C6H12O6 + 6O2
Oxidation
11/16/2022 88
89. Reduction Reaction
The gain of electrons to a substance.
Or the loss of oxygen.
glucose
6CO2 + 6H2O C6H12O6 + 6O2
Reduction
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90. Breakdown of Photosynthesis
Two main parts (reactions).
1. Light Reaction or
Light Dependent Reaction
Produces energy from solar power
(photons) in the form of ATP and NADPH.
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91. Breakdown of Photosynthesis
2. Calvin Cycle or
Light Independent Reaction or
Carbon Fixation or
C3 Fixation
Uses energy (ATP and NADPH) from light
rxn to make sugar (glucose).
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92. 1. Light Reaction (Electron Flow)
Occurs in the Thylakoid membranes
During the light reaction, there are two
possible routes for electron flow.
A. Cyclic Electron Flow
B. Noncyclic Electron Flow
11/16/2022 92
93. A. Cyclic Electron Flow
Occurs in the thylakoid membrane.
Uses Photosystem I only
P700 reaction center- chlorophyll a
Uses Electron Transport Chain (ETC)
Generates ATP only
ADP + ATP
P
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94. A. Cyclic Electron Flow
P700
Primary
Electron
Acceptor
e-
e-
e-
e-
ATP
produced
by ETC
Photosystem I
Accessory
Pigments
SUN
Photons
11/16/2022 94
95. B. Noncyclic Electron Flow
Occurs in the thylakoid membrane
Uses PS II and PS I
P680 rxn center (PSII) - chlorophyll a
P700 rxn center (PS I) - chlorophyll a
Uses Electron Transport Chain (ETC)
Generates O2, ATP and NADPH
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96. B. Noncyclic Electron Flow
P700
Photosystem I
P680
Photosystem II
Primary
Electron
Acceptor
Primary
Electron
Acceptor
ETC
Enzyme
Reaction
H2O
1/2O2 + 2H+
ATP
NADPH
Photon
2e-
2e-
2e-
2e-
2e-
SUN
Photon
11/16/2022 96
97. B. Noncyclic Electron Flow
ADP + ATP
NADP+ + H NADPH
Oxygen comes from the splitting of
H2O, not CO2
H2O 1/2 O2 + 2H+
(Reduced)
P
(Reduced
)
(Oxidized)
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98. Chemiosmosis
Powers ATP synthesis.
Located in the thylakoid membranes.
Uses ETC and ATP synthase (enzyme) to
make ATP.
Photophosphorylation: addition of
phosphate to ADP to make ATP.
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99. Chemiosmosis
H+ H+
ATP Synthase
H+ H+ H+ H+
H+ H+
high H+
concentration
H+
ADP + P ATP
PS II PS I
E
T
C
low H+
concentration
H+
Thylakoid
Space
Thylakoid
SUN (Proton Pumping)
11/16/2022 99
100. Calvin Cycle
Carbon Fixation (light independent rxn).
C3 plants (80% of plants on earth).
Occurs in the stroma.
Uses ATP and NADPH from light rxn.
Uses CO2.
To produce glucose: it takes 6 turns and uses
18 ATP and 12 NADPH.
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