This document discusses two types of enzyme catalysis: covalent and electrostatic. Covalent catalysis involves the transient formation of a covalent bond between an enzyme's nucleophilic group (such as an amino acid side chain) and an electrophilic group on the substrate. This is exemplified by the decarboxylation of acetoacetate through Schiff base formation with a lysine residue. Electrostatic catalysis enhances reaction rates through the arrangement of charged groups within the enzyme's active site to stabilize transition states. The local low dielectric environment of the active site strengthens electrostatic interactions.
This ppt describes the overview of enzyme regulation and Allosterism. Presented since October 23,2017GC at Addis Ababa University, School of Medicine, Department of medical biochemistry.
Active sites of the enzyme is that point where substrate molecule bind for the chemical reaction. It is generally found on the surface of enzyme and in some enzyme it is a “Pit” like structure
The active site is a three-dimensional cleft formed by groups that come from different parts of the amino acid sequence
The active site takes up a relatively small part of the total volume of an enzyme
Active sites are clefts or crevices
Substrates are bound to enzymes by multiple weak attractions.
The specificity of binding depends on the precisely defined arrangement of atoms in an active site.
this will be useful to understand about the new topics such as abzymes, ribozymes and also isoenzymes. You have to clear that ribozymes are not protein. because all enzymes are proteins but all proteins are not enzymes except ribozymes
This presentation deals with basics of enzyme kinetics and introduction to various plots which aid in understanding the mechanism of inhibition of enzymes.
A comprehensive coverage of Enzymes including basics, mechanisms of enzyme catalysis, enzyme inhibition and clinical applications, mostly based on Stryer- Biochemistry. The slides were intended for MBBS teaching, but should benefit the students of Biochemistry and allied sciences.
Prepared in Sept 2015
This ppt includes overall idea of what is enzymes, how it works, mechanism of enzymes, kinetics and how to inhibit enzyme activities. The reference is the ideal book for biochemistry - Lehninger . Understanding is easy for everyone.
This ppt describes the overview of enzyme regulation and Allosterism. Presented since October 23,2017GC at Addis Ababa University, School of Medicine, Department of medical biochemistry.
Active sites of the enzyme is that point where substrate molecule bind for the chemical reaction. It is generally found on the surface of enzyme and in some enzyme it is a “Pit” like structure
The active site is a three-dimensional cleft formed by groups that come from different parts of the amino acid sequence
The active site takes up a relatively small part of the total volume of an enzyme
Active sites are clefts or crevices
Substrates are bound to enzymes by multiple weak attractions.
The specificity of binding depends on the precisely defined arrangement of atoms in an active site.
this will be useful to understand about the new topics such as abzymes, ribozymes and also isoenzymes. You have to clear that ribozymes are not protein. because all enzymes are proteins but all proteins are not enzymes except ribozymes
This presentation deals with basics of enzyme kinetics and introduction to various plots which aid in understanding the mechanism of inhibition of enzymes.
A comprehensive coverage of Enzymes including basics, mechanisms of enzyme catalysis, enzyme inhibition and clinical applications, mostly based on Stryer- Biochemistry. The slides were intended for MBBS teaching, but should benefit the students of Biochemistry and allied sciences.
Prepared in Sept 2015
This ppt includes overall idea of what is enzymes, how it works, mechanism of enzymes, kinetics and how to inhibit enzyme activities. The reference is the ideal book for biochemistry - Lehninger . Understanding is easy for everyone.
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Summary
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Enzyme, a substance that acts as a catalyst in living organisms, regulating the rate at which chemical reactions proceed without itself being altered in the process.
In the induced-fit theory of enzyme-substrate binding, a substrate approaches the surface of an enzyme (step 1 in box A, B, C) and causes a change in the enzyme shape that results in the correct alignment of the catalytic groups (triangles A and B; circles C and D represent substrate-binding groups on the enzyme that are essential for catalytic activity). The catalytic groups react with the substrate to form products (step 2). The products then separate from the enzyme, freeing it to repeat the sequence (step 3). Boxes D and E represent examples of molecules that are too large or too small for proper catalytic alignment. Boxes F and G demonstrate binding of an inhibitor molecule (I and I′) to an allosteric site, thereby preventing interaction of the enzyme with the substrate. Box H illustrates binding of an allosteric activator (X), a nonsubstrate molecule capable of reacting with the enzyme.
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Key People: Richard Henderson Emil Fischer Maud Leonora Menten Günter Blobel Arieh Warshel
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A brief treatment of enzymes follows. For full treatment, see protein: Enzymes.
The biological processes that occur within all living organisms are chemical reactions, and most are regulated by enzymes. Without enzymes, many of these reactions would not take place at a perceptible rate. Enzymes catalyze all aspects of cell metabolism. This includes the digestion of food, in which large nutrient molecules (such as proteins, carbohydrates, and fats) are broken down into smaller molecules; the conservation and transformation of chemical energy; and the construction of cellular macromolecules from smaller precursors. Many inherited human diseases, such as albinism and phenylketonuria, result from a deficiency of a particular enzyme.
rennet in cheese making
rennet in cheese making
Rennet, which contains the protease enzyme chymosin, being added to milk during cheese making.
Enzymes also have valuable industrial and medical applications. The fermenting of wine, leavening of bread, curdling of cheese, and brewing of beer have been practiced from earliest times, but not until the 19th century were these reactions understood to be the result of the catalytic activity of enzymes. Since then, enzymes han
This presentation intends to offer the basic features of plant metabolism along with the different types of mechanisms to regulate and control the metabolic pathways.
Enzymes are biological molecules (proteins) that act as catalysts and help complex reactions occur everywhere in life. Let's say you ate a piece of meat. Proteases would go to work and help break down the peptide bonds between the amino acids.
It covers enzyme kinetics, classification of enzymes, catalysis, types of catalysis, nomenclature of enzymes, apoenzymes, cofactors, isoenzymes, holoenzyme, factors affecting the rate of chemical reaction, clinical importance of enzymes. It is useful for the students of life sciences and biochemistry as well. The slides help even the teachers teaching basics of enzyme kinetics at the UG and PG levels.
Glucose homeostasis in liver and pancreas, GLUCOSE is the major source of energy to the brain, insulin hormone has been maintained the glucose in our body
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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.
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A brief information about the SCOP protein database used in bioinformatics.
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In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
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Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
2. INTRODUCTION:
Enzymes are biocatalyst. They increases
the rate of chemical reactions taking place
within living cells without themselves
suffering any overall change. The
reactants of enzyme-catalysed reactions
are termed substrates and each enzyme
quit specific in character, acting on a
particular substrate to produce particular
product
3.
4. Catalysis:
A catalyst accelerates a chemical reactions
without changing its extent and can be
removed unchanged from amongst the
end products of the reaction. It has no
overall thermodyanamic effect: the
amount of energy liberated or taken up
when a reaction has been completed will
be the same whether a catalyst is present
or not.
5. Covalentcatalysis:
Covalent Catalysis accelerates reaction
rates through the transient formation of a
catalyst-substrate covalent bond.
Usually, nucleophilic group on enzyme
attacks an electrophilic
group on the substrate = nucleophilic
catalysis
Example: decarboxylation ofacetoacetate
9. Certain Amino Acid Side Chains and
Coenzymes Can Serve as Covalent Catalysts
Enzymes commonly employ covalent catalytic
mechanisms as is indicated by the large variety
of covalently linked enzyme–substrate reaction
intermediates that have been isolated.For
example,the enzymatic decarboxylation of
acetoacetate proceeds, much as described
above, through Schiff base formation with an
enzyme Lys residue’s ε-amino group.
The covalent intermediate,in this case, has
been isolated through NaBH4 reduction of its
imine bond to an amine,thereby irreversibly
inhibiting the enzyme.
11. Continued..
Other enzyme functional groups that
participate in covalent catalysis include the
imidazole moiety of His, the thiol group of
Cys, the carboxyl function of Asp, and the
hydroxyl group of Ser.In addition,several
coenzymes, most notably thiamine
pyrophosphate (Section 17-3Ba) and
pyridoxal phosphate (Section 26-1Aa),
function in association with their
apoenzymes mainly as covalent catalysts.
12. Electrostatic Catalysis
The binding of substrate generally excludes
water from an enzyme’s active site.The local
dielectric constant of the active site therefore
resembles that in an organic solvent, where
electrostatic interactions are much stronger than
they are in aqueous solutions .
The charge distribution in a medium of low
dielectric constant can greatly influence
chemical reactivity.Thus,as we have seen, the
pK’s of amino acid side chains in proteins may
vary by several units from their nominal values
because of the proximity of charged groups
13. Continued..
Although experimental evidence and theoretical
analyses on the subject are still sparse,there are
mounting indications that the charge distributions
about the active sites of enzymes are arranged so as to
stabilize the transition states of the catalyzed
reactions.
Such a mode of rate enhancement,which resembles
the form of metal ion catalysis discussed above,is
termed electrostatic catalysis.Moreover,in several
enzymes,these charge distributions apparently serve
to guide polar substrates toward their binding sites so
that the rates of these enzymatic reactions are greater
than their apparent diffusion-controlled limits .