Peroxisomes are microbody organelles found in the cytoplasm of eukaryotic cells that perform important metabolic functions. They contain enzymes for oxidation reactions that produce hydrogen peroxide as a byproduct, and also contain the enzyme catalase to break down hydrogen peroxide. Peroxisomes are involved in lipid biosynthesis and fatty acid oxidation. Related organelles like glyoxysomes in plants and glycosomes in kinetoplastids also carry out metabolic functions tailored to their cellular environments.
Structure and functon of golgi apparatusICHHA PURAK
The Power point presentation consists of 77 slides including following heads
Introduction
Discovery
Distribution
Origin
Shape
Chemical composition
Structure
Common functions
Cell specific functions
Proteoglycans are assembled in G A
Lpid metabolism in G A
Protein sorting
Vesicular Tubular Clusters (VTCs)
Only properly folded and assembled protein can leave ER
Proteins leave ER in COPII coated transport vesicles
summary
questions
References
This Power Point Presentation (PPT) entitled “ Structure and Function of Lysosome”includes 43 slides with following sub- heads.
DEFINITION
INTRODUCTION/ STRUCTURE OF LYSOSOME
DISCOVERY OF LYSOSOME
DISTRIBUTION/LOCATION OF LYSOSOME
ORIGIN/ SYNTHESIS OF LYSOSOME
SHAPE AND SIZE OF LYSOSOME
CHEMICAL COMPOSITION OF LYSOSOME
LYSOSOMES ARE KNOWN AS SUICIDE BAGS
HOW THE CELL IS PROTECTED FROM LYSOSOME RUPTURE
COMMON FUNCTION OF LYSOSOME
TYPES OF LYSOSOME
DISORDERS IN HUMAN RELATED WITH LYSOSOME
SUMMARY
QUESTIONS
BOOKS CONSULTED
REFERENCES
Structure and functon of golgi apparatusICHHA PURAK
The Power point presentation consists of 77 slides including following heads
Introduction
Discovery
Distribution
Origin
Shape
Chemical composition
Structure
Common functions
Cell specific functions
Proteoglycans are assembled in G A
Lpid metabolism in G A
Protein sorting
Vesicular Tubular Clusters (VTCs)
Only properly folded and assembled protein can leave ER
Proteins leave ER in COPII coated transport vesicles
summary
questions
References
This Power Point Presentation (PPT) entitled “ Structure and Function of Lysosome”includes 43 slides with following sub- heads.
DEFINITION
INTRODUCTION/ STRUCTURE OF LYSOSOME
DISCOVERY OF LYSOSOME
DISTRIBUTION/LOCATION OF LYSOSOME
ORIGIN/ SYNTHESIS OF LYSOSOME
SHAPE AND SIZE OF LYSOSOME
CHEMICAL COMPOSITION OF LYSOSOME
LYSOSOMES ARE KNOWN AS SUICIDE BAGS
HOW THE CELL IS PROTECTED FROM LYSOSOME RUPTURE
COMMON FUNCTION OF LYSOSOME
TYPES OF LYSOSOME
DISORDERS IN HUMAN RELATED WITH LYSOSOME
SUMMARY
QUESTIONS
BOOKS CONSULTED
REFERENCES
Introduction
Discovery
Structure
Outer membrane
Inter membrane space
Inner membrane
Cristae
Matrix
Functions
Conclusion
References
The word mitochondrion comes from the Greek word mitos, thread + chondrion, granule.
Mitochondria play a critical role in the generation of metabolic energy in eukaryotic cells .
Mitochondria produce ATP using energy stored in food molecules.
Structure and functions of MitochondriaICHHA PURAK
This Power Point Presentation (PPT) entitled “Structure and Functions of Mitochondria” consists of 118 slides with following sub-heads
INTRODUCTION
HISTORY
ORIGIN AND EVOLUTION OF MITOCHONDRIA
SYNTHESIS OF MITOCHONDRIA
ISOLATION OF MITOCHNDRIA
SHAPE , SIZE AND NUMBER OF MITOCHONDRIA
STRUCTURE OF MITOCHONDRIA
CHEMICAL COMPOSITION OF MITOCHONDRIA
FUNCTIONS OF MITOCHONDRIA
MITOCHONDRIA –POWER HOUSE OF CELL
MITOCHONDRIAL DNA/ GENOME
TRANSPORT OF PROTEINS INTO MITOCHONDRIA
MITOCHONDRIAL INHERITANCE
MITOCHONDRIAL DISEASES IN HUMAN
SUMMARY
QUESTIONS
BOOKS CONSULTED
REFERENCES
Basics only
Ultrastructure, Chemical composition and Functions of Golgi complex
• Golgi apparatus is a complex network of smooth membrane enclosed organelle which helps in collection, packaging, distribution and secretion of biomolecules.
• Golgi apparatus is referred as Golgi complex, Golgi bodies, Golgi some, dictyosomes, lipochondria, Dalton Complex, Baker’s bodies, Carbohydrate factory, ‘traffic police’ of cell.
Introduction
Discovery
Structure
Outer membrane
Inter membrane space
Inner membrane
Cristae
Matrix
Functions
Conclusion
References
The word mitochondrion comes from the Greek word mitos, thread + chondrion, granule.
Mitochondria play a critical role in the generation of metabolic energy in eukaryotic cells .
Mitochondria produce ATP using energy stored in food molecules.
Structure and functions of MitochondriaICHHA PURAK
This Power Point Presentation (PPT) entitled “Structure and Functions of Mitochondria” consists of 118 slides with following sub-heads
INTRODUCTION
HISTORY
ORIGIN AND EVOLUTION OF MITOCHONDRIA
SYNTHESIS OF MITOCHONDRIA
ISOLATION OF MITOCHNDRIA
SHAPE , SIZE AND NUMBER OF MITOCHONDRIA
STRUCTURE OF MITOCHONDRIA
CHEMICAL COMPOSITION OF MITOCHONDRIA
FUNCTIONS OF MITOCHONDRIA
MITOCHONDRIA –POWER HOUSE OF CELL
MITOCHONDRIAL DNA/ GENOME
TRANSPORT OF PROTEINS INTO MITOCHONDRIA
MITOCHONDRIAL INHERITANCE
MITOCHONDRIAL DISEASES IN HUMAN
SUMMARY
QUESTIONS
BOOKS CONSULTED
REFERENCES
Basics only
Ultrastructure, Chemical composition and Functions of Golgi complex
• Golgi apparatus is a complex network of smooth membrane enclosed organelle which helps in collection, packaging, distribution and secretion of biomolecules.
• Golgi apparatus is referred as Golgi complex, Golgi bodies, Golgi some, dictyosomes, lipochondria, Dalton Complex, Baker’s bodies, Carbohydrate factory, ‘traffic police’ of cell.
slide 2 central dogma
slide 3 key molecules used in translation
slide 4,5,6,7 all the key molcules with detail explanation
slide 8 phases of translation
slide 9 initiation and its process
slide 10 explanation initiation
slide 11 elongation and translocation
slide 12 process and steps of elongation and tRNA recharge in detail
slide 13 termination and its stages.
slide 14 diagrammatic representation of all the steps of termination with discrption
slide 15 thank you
Transcription in eukaryotes: A brief view
Transcription is the process by which single stranded RNA is synthesized by double stranded DNA. Transcription in eukaryotes and prokaryotes has many similarities while at the same time both showing their individual characteristics due to the differences in organization. RNA Polymerase (RNAP or RNA Pol) is different in prokaryotes and eukaryotes. Coupled transcription is seen in prokaryotes but not in Eukaryotes. In eukaryotes the pre-RNA should be spliced first to be translated.
In Eukaryotic transcription, synthesis of RNA occurs in the 3’→5’ direction. The 3’ end is more reactive due to the hydroxide group. 5’ end containing phosphate groups meanwhile, is not very reactive when it comes to adding new nucleotides. In Eukaryotes, the whole genome is not transcribed at once. Only a part of the genome is transcribed which also acts as the first, principle stage of genetic regulation.
Eukaryotes have five nuclear polymerases:
• RNA Polymerase I: This produces rRNA (23S, 5.8S, and 18S) which are the major components in a ribosome. This also produces pre-rRNA in yeasts.
• RNA Polymerase II: Helps in the production of mRNA (messenger RNA), snRNA (small, nuclear RNA), miRNA. This is the most studied type and requires several transcription factors for its binding
• RNA Polymerase III: This synthesizes tRNA (transfer RNA), 5S rRNA and other small RNAs required in the cytosol and nucleus.
• RNA Polymerase IV: Synthesizes siRNA (small interfering RNA) in plants.
• RNA Polymerase V: This is the least studied polymerase and synthesizes siRNA-directed heterochromatin in plants.
Eukaryotic transcription can be broadly divided into 4 stages:
• Pre-Initiation
• Initiation
• Elongation
• Termination
Transcription is an elaborate process which cells use to copy the genetic information stored in DNA into RNA. This pre-RNA is modified into mRNA before being transcribed to proteins. Transcription is the first step to utilizing the genetic information in a cell. Both Eukaryotes and Prokaryotes employ this process with the basic phases remaining the same. However eukaryotic transcription is more complex indicating the changes transcription has undergone towards perfection during evolution.
Basics only
A variety of small cellular components bounded by single membrane found in Plant and
animal cell. Microbodies are of two types; Peroxisomes and glyoxysomes
Carbohydrates are a class of biomolecules that are important sources of energy and structural components in living organisms. They are made up of carbon, hydrogen, and oxygen atoms, and they are classified based on their size and the number of sugar units they contain.
Peroxisomes are small, membrane-enclosed organelles that contain enzymes involved in a variety of metabolic reactions, including several aspects of energy metabolism.
Segmentation in Drosophila melanogaster Shreya Ahuja
All human beings, no matter how different we look, have a certain basic body plan established in us (for instance, all of us have our heads are placed right above our shoulders with arms stretching out from either side). Drosophila is no exception. This presentation talks about establishment of the body plan in Drosophila, how and when the different Segmentation Genes are expressed in Drosophila to give rise to its segmented body pattern.
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
2. Microbody
organelles
found in the
cytoplasm
PEROXISOMES
in higher
eukaryotic cells.
GLYCOSOMES in
kinetoplastids
GLYOXYSOMES
in plant cells
• Related microbody organelles that perform differing
metabolic functions tailored to their cellular
environments.
• The close evolutionary relationship of these
organelles is most clearly evidenced by the
conservation of proteins involved in matrix protein
import and biogenesis.
3. Oxidation reactions leading to the production of hydrogen peroxide. Because hydrogen peroxide is
harmful to the cell, peroxisomes also contain the enzyme catalase, which decomposes hydrogen
peroxide either by converting it to water or by using it to oxidize another organic compound.
Peroxisomes are involved in lipid biosynthesis. In animal cells, cholesterol and Dolichol are
synthesized in peroxisomes as well as in the endoplasmic reticulum
In plants, peroxisomes in seeds are responsible for the conversion of stored fatty acids to
carbohydrates, which is critical to providing energy and raw materials for growth of the
germinating plant.
Peroxisomes in leaves are involved in photorespiration, which serves to metabolize a side product
formed during photosynthesis.
MAIN FUNCTIONS OF PEROXISOMES
4. OXIDATION REACTIONS OF PEROXISOMES
A variety of substrates are broken down by such oxidative reactions in peroxisomes, including uric acid, amino acids, and fatty acids. The
oxidation of fatty acids is a particularly important example, since it provides a major source of metabolic energy. In animal cells, fatty
acids are oxidized in both peroxisomes and mitochondria, but in yeasts, fatty acid oxidation is restricted to peroxisomes.
Beta oxidation of fatty acids occurs in the peroxisomes (a eukaryotic organelle) in addition to the mitochondria, though in a modified
form.
A primary function of peroxisomal beta oxidation is to shorten very long chain fatty acids so they can be degraded in the mitochondrion.
Peroxisomal oxidation has advantages over mitochondrial oxidation - fatty acids can diffuse across the peroxisomal membrane. After
very long chain fatty acids are partly degraded, they are attached to carnitine for transport to mitochondria.
5.
6. Peroxisomes contain oxidative enzymes, such as catalase, D-amino acid oxidase, and uric acid oxidase.
Certain enzymes within the peroxisome, by using molecular oxygen, remove hydrogen atoms from specific organic
substrates in an oxidative reaction, producing hydrogen peroxide (H2O2, itself toxic)
Catalase, another peroxisomal enzyme, uses this H2O2 to oxidize other substrates, including phenols, formic acid,
formaldehyde, and alcohol, by means of the peroxidation reaction, thus eliminating the poisonous hydrogen peroxide.
This reaction is important in liver and kidney cells, where the peroxisomes detoxify various toxic substances that enter the
blood. About 25% of the ethanol humans drink is oxidized to acetaldehyde in this way. In addition, when excess H2O2
accumulates in the cell, catalase converts it to H2O through this reaction
DETOXIFICATION OF REACTIVE OXYGEN SPECIES
7. LIPID SYNTHESIS IN PEROXISOMES
• Plasmalogens are relatively rare in some tissues but form a significant fraction of the membranes in nervous tissue. Some
of the steps in plasmalogen biosynthesis are localized in peroxisomes, and some peroxisomal disorders impair plasmalogen
biosynthesis.
• Cholesterol: There is now considerable evidence that peroxisomes not only have a role in cholesterol oxidation but also in
cholesterol biosynthesis.
Acetyl CoA Acetoacetyl CoA
THIOLASE
Mevalonate Mevalonate-5-Phosphate
MEVALONATE
KINASE
3-Hydroxy-3-
methylglutaryl CoA
HMG
REDUCTASE
Initiation steps in cholesterol synthesis
• Bile Acids: Peroxisomes play an important role in the biosynthesis of bile acids because a peroxisomal β-oxidation step is
required for the formation of the mature C24-bile acids from C27-bile acid intermediates. In addition, de novo synthesized
bile acids are conjugated within the peroxisome.
9. GLYOXYLATE CYCLE IN PEROXISOMES
(occurs in plants)
• Plants are capable of synthesizing carbohydrates from fatty acids via the glyoxylate cycle,
which is a variant of the citric acid cycle.
• The Glyoxylate cycle provides the means to convert C2-units to C4-precursors for
biosynthesis, allowing growth on fatty acids and C2-compounds.
• The operation of the Glyoxylate cycle requires transport of several intermediates across
the peroxisomal membrane.
Glyoxysome
reactions
11. GLYCOSOMES OF KINETOPLASTIDS
The glycosome is a membrane-enclosed organelle that contains the glycolytic enzymes.
Found in a few species of protozoa including the Kinetoplastida which included the suborders Trypanosomatina and
Bodonina, and Leishmania.
The organelle is bounded by a single membrane and contains a dense proteinaceous matrix. It is believed to have
evolved from the peroxisome.
There has been a variety of evidence found biochemically to give evidence that glycosomes are present in cells. In
the organelle that is assumed to be a glycosome, numerous proteins are found. These include glycogen synthase,
phosphorylase, and branching and de-branching enzymes for glycogen. All of these are regulatory enzymes that are
needed in glycogen synthesis.
12. SOME OTHER FUNCTIONS OF PEROXISOMES
• The enzymes in peroxisomes break down long chain fatty acids by the process of oxidation. If allowed to accumulate these
fatty acids can damage structures such as the myelin ‘insulation’ sheath surrounding nerve fibers in the brain.
• In normal human hepatocytes, the intermediary-metabolic enzyme alanine-glyoxylate aminotransferase (AGT) is located
within the peroxisomes. This protein is involved in preventing excess quantities of the chemical ‘oxalate’ from building up.
A type of kidney stone is produced when oxalate joins with calcium to produce calcium oxalate. The proper functioning of
this enzyme is therefore important.
• One of the enzymes found in peroxisomes from fireflies is called luciferase. This helps some males produce a bright flash
of green/yellow light to attract females. The duration of the flash and the interval between the flashes is species specific
and easily seen by females flying at night. In some species the female will flash in reply.
• A rare but fatal disorder of peroxisome molecular biology is Zellweger Syndrome. It is an inherited condition in which
peroxisomal enzymes produced in the cytoplasm are unable to cross the membrane barrier and enter the matrix of the
peroxisome. In this condition peroxisomes are present but only as ‘ghost’ or empty organelles.
13. ISOLATION OF PEROXISOMES
Tissue culture is homogenised. Kidney cells and hepatocytes contain
large peroxisomes as compared to those found in fibroblasts or muscle
cells. Isolated peroxisomes can be used to study fatty acid oxidation,
amino acid metabolism lipid synthesis etc.
Serial centrifugations at 1000g, 2000g and 25000g remove cell debris,
nuclei, mitochondria and lipids to obtain a crude peroxisomal fraction
(lysosomes, ER, peroxisomes, light mitochondria)
Density gradient ultra-centrifuge to obtain peroxisomal fraction at the
bottom of the tube.
Degree of purification of peroxisomes can be evaluated by comparing
concentrations of catalase (peroxisome marker) and cytochrome C
oxidase (mitochondrial marker)