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Lac Operon- Gene Regulation in Bacteria
The lac operon, found in E. coli bacteria, is a remarkable genetic system that controls the metabolism of lactose, a sugar commonly present in milk. This operon comprises three crucial structural genes: lacZ, lacY, and lacA, responsible for encoding the essential enzymes needed to break down lactose into glucose and galactose. Its significance in the…
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Enzyme-substrate interaction
Enzymes are crucial biomolecules that facilitate specific chemical reactions in living organisms. They do this by binding to specific molecules known as substrates, and this interaction is key to their function. Enzymes can only catalyze specific types of reactions, and this specificity is determined by the unique shape of their active site, which is in…
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RNA Interference (RNAi)
The article provides an introduction to RNA interference (RNAi), a process by which the expression of specific genes is regulated at the post-transcriptional level. It explains the biochemistry of siRNA and shRNA, the mechanism of action, and the downstream effects of RNAi. The article also discusses the role of RNAi in cancer treatment and defense…
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Ion Exchange Chromatography
Introduction Ion exchange chromatography (IEC) is a type of liquid chromatography that separates molecules based on their charge. It is a widely used technique in biochemistry and analytical chemistry for the purification and isolation of biomolecules such as proteins, nucleic acids, and small molecules. Principles of Ion Exchange Chromatography IEC utilizes a stationary phase, which…
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ABC Model of Flowering
The ABC model of flowering is a genetic and molecular framework that explains how plants transition from vegetative growth to reproductive development. The model proposes that three groups of genes, referred to as A, B, and C genes, work together to regulate this process. A genes are responsible for initiating the flowering process independently of…
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DNA Fingerprinting
The article discusses DNA fingerprinting, a technique used to identify individuals based on their unique DNA pattern. It explains the principle of DNA fingerprinting, the methods used, and its various applications such as criminal investigations, paternity testing, and medical research. The advantages and disadvantages of DNA fingerprinting are also discussed along with the ethical and…
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Eukaryotic DNA replication (Basic)
Eukaryotic DNA replication is a complex and highly regulated process that occurs in the cell nucleus. It is essential for the maintenance of genomic integrity and the proper segregation of chromosomes during cell division. The molecular basis of eukaryotic DNA replication can be broken down into several key steps and components: The molecular machinery responsible…
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GPCR Signalling Pathway
The G protein-coupled receptor (GPCR) signalling pathway plays a vital role in transmitting signals from extracellular molecules, such as hormones, to intracellular effectors. This pathway involves a series of steps, including hormone binding to the GPCR, activation of the G protein, signal transduction, termination of the signal, and ultimately leading to a cellular response. The…
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Prokaryotic Transcription
Introduction: Promoter recognition and binding: Initiation: Elongation: Termination: In summary, Prokaryotic transcription is the process of converting genetic information from DNA to RNA. This process is mediated by the enzyme RNA polymerase. The process includes promoter recognition and binding, initiation, elongation, and termination. The RNA polymerase recognizes the promoter by the help of sigma factor…
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Electrophoretic Mobility Shift Assay: EMSA
The text describes Electrophoretic Mobility Shift Assay (EMSA), a molecular biology technique used to study protein-DNA interactions. EMSA is based on the principle that proteins can bind to specific regions of DNA and alter its conformation, affecting the mobility of the DNA in an electric field. This technique is used to study transcription regulation, DNA…
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Apoptotic Pathway
Apoptotic pathways, the intricate networks regulating programmed cell death, are vital for various biological processes and disease outcomes. Understanding these pathways, including the intrinsic and extrinsic routes, sheds light on cell death mechanisms and their implications in health and disease. The interplay between pro-apoptotic and anti-apoptotic proteins and the activation of caspases shape the fate…
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Enzymes : classification
Enzymes are incredibly important biomolecules that play a crucial role in the proper functioning of living organisms. They catalyze specific chemical reactions, making it possible for various biological processes such as metabolism, DNA replication, and cell signaling to occur efficiently. The structure of enzymes is complex, with different levels of organization, including the primary, secondary,…
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Eukaryotic transcription
The eukaryotic transcription process is a fundamental process for gene expression in eukaryotic cells. This process involves several steps that are tightly regulated and require the coordinated action of multiple proteins and regulatory factors. The initiation step is the first and most critical step in the transcription process. It involves the recruitment of RNA polymerase…
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Circular Dichroism (CD) Technique
Circular dichroism (CD) is a powerful spectroscopic technique used to study the structure and properties of chiral molecules, such as proteins, nucleic acids, and carbohydrates. It is based on the differential absorption of left and right circularly polarized light by chiral molecules, which can provide information on their secondary, tertiary, and quaternary structures. In this…
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Cell Cycle (Basic)
I. Introduction II. Interphase A. G1 phase B. S phase C. G2 phase III. Mitotic Phase IV. Conclusion
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Restriction Endonucleases
Restriction endonucleases, the DNA-cutting enzymes, are indispensable in molecular biology research. Classified into four types based on recognition sites, Type II enzymes stand out as the most widely used. They cleave DNA at specific sequences, generating fragments with blunt or sticky ends. Despite their complexity, Type I and III enzymes have limited use due to…
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Post transcriptional processingÂ
Post-transcriptional processing refers to the set of modifications and events that occur to the RNA molecule after transcription, but before translation. These modifications are important for the stability, localization, and translation of the RNA molecule. Capping, polyadenylation, splicing, RNA editing, RNA localization, and RNA stability are all important aspects of post-transcriptional processing.
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DNA Footprinting
The DNA footprinting technique is used to study the interactions between DNA and proteins. This allows researchers to identify which regions of DNA are bound by specific proteins and how they interact with DNA. DNA footprinting has various methods like chemical, thermal, and electrophoretic mobility shift assays, which are used to map protein-DNA interactions, study…
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Cell cycle regulatory proteins
I. Introduction II. Cyclin-dependent kinases (CDKs) III. Cyclin-dependent kinase inhibitors (CKIs) IV. Retinoblastoma protein (Rb) V. Tumor protein p53 (p53) VI. Conclusion
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Osmosis
Osmosis is a process that occurs naturally in all living things, including plants and animals. It is a type of passive transport that involves the movement of water molecules across a selectively permeable membrane from an area of high concentration to an area of low concentration. This movement of water molecules helps maintain the balance…
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Translation
The molecular basis of translation is the process by which the genetic information stored in RNA is converted into a functional protein. This process occurs on ribosomes, which are large complexes of proteins and RNA molecules. The process of translation is divided into three main stages: initiation, elongation, and termination. In the initiation stage, a…
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X-ray Diffraction Technique
The X-ray diffraction (XRD) technique is a powerful tool for studying the structure of crystalline materials. It works by shining X-rays on a crystalline material and detecting the diffracted X-rays on a detector, creating a pattern of diffraction peaks. The angle and intensity of these peaks can be used to determine the crystal structure, unit…
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Eukaryotic cell cycle regulation
The cell cycle is a precisely regulated process essential for cell growth and division. It consists of four distinct phases: G1, S, G2, and mitosis. Each phase plays a crucial role in ensuring accurate cell division and maintaining genomic integrity. The cell cycle is governed by various checkpoints that assess DNA integrity, availability of growth…
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Electron Transport Chain: The Powerhouse of Cellular Respiration
Introduction: Structure of the Electron Transport Chain Complexes of ETC: The ETC is made up of four protein complexes: Complex I, Complex II, Complex III, and Complex IV. Each complex has a specific function in the ETC, and the electron transfer between complexes is tightly regulated. Complex I (NADH-CoQ oxidoreductase): Complex I is the first…
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Post translational processingÂ
Post-translational processing refers to the series of modifications that occur to a protein after it has been synthesized by the ribosome. These modifications can include folding, cleavage, phosphorylation, acetylation, glycosylation, ubiquitination, and methylation. Each modification is mediated by a specific enzyme and can have a significant impact on the stability, activity, and localization of the…
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Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI) is a medical imaging technique that creates detailed images of the internal structures of the body using magnetic fields and radio waves. MRI is a non-invasive diagnostic tool that provides high-quality images of soft tissues, organs, and bones without exposing patients to harmful radiation. The basic principle of MRI is to…
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RFLP (Restriction Fragment Length Polymorphism)
The excerpt introduces RFLP, a molecular biology method for detecting DNA sequence variations. It explains the principle of restriction enzymes cutting specific DNA sequences and generating restriction fragments. The procedure involves DNA isolation, digestion, gel electrophoresis, and hybridization with labeled probes. RFLP’s applications span genetics, forensic science, and medical diagnostics. Despite its replacement by newer…
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Peroxisome: Structure and Function
Peroxisomes are small, spherical organelles found in eukaryotic cells that play a crucial role in cellular metabolism. They are enclosed by a single membrane and contain enzymes responsible for specific metabolic reactions, such as the metabolism of lipids and the detoxification of harmful substances. Peroxisomes are distinct from lysosomes, as they do not degrade macromolecules.…
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Molecular genetics of cancer
This topic discusses the molecular genetics of cancer, which involves the study of genetic and molecular changes that occur in cells as they become cancerous. It explains the role of oncogenes and tumor suppressor genes in the development of cancer and how mutations in these genes can disrupt the balance between cell growth and proliferation.…
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Mass Spectrometry (MS) Technique
The article discusses the principles, techniques, and applications of Mass Spectrometry (MS) from a biophysics perspective. It explains how MS is used to study the structure, dynamics, and interactions of biomolecules and how it can be applied to a wide range of biomolecules, including proteins, nucleic acids, lipids, and small molecules. The article also discusses…
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Random Amplified Polymorphic DNA (RAPD)
Introduction: Principles of RAPD: Procedure: RAPD analysis involves the following steps: Applications: Limitations: Conclusion:
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Centrosomes Structure and Function
Centrosomes are vital organelles in eukaryotic cells that play an essential role in the organization of the cell’s microtubule cytoskeleton and the proper distribution of genetic material during cell division. Composed of two cylindrical centrioles surrounded by pericentriolar material, these organelles act as nucleation sites for the formation of microtubules, which are crucial for cell…
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The p53 gene
The p53 gene is a crucial gene in the human body that plays a critical role in regulating cell growth and division. The gene encodes a protein called p53, which acts as a checkpoint protein to monitor the integrity of the genome and respond to DNA damage. When DNA damage is detected, p53 can activate…
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Functional Magnetic Resonance Imaging
Functional Magnetic Resonance Imaging (fMRI) is a powerful medical imaging technique used to study brain function. It measures changes in blood flow in the brain using MRI technology, which can be used to infer changes in neural activity. fMRI is commonly used in neuroscience, psychology, and psychiatry to investigate a wide range of questions related…
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Apoptosis – Molecular Basis
Apoptosis, also known as programmed cell death, is a crucial process in multicellular organisms that plays a key role in maintaining tissue homeostasis and responding to cellular stress and damage. Dysregulation of apoptosis can lead to various diseases, including cancer and autoimmunity. The molecular basis of apoptosis involves two main pathways: the extrinsic pathway, which…
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Chromatin Packaging
Chromatin packaging is a crucial process for the proper functioning of cells. It allows the genetic material to be compacted and organized within the nucleus, which is essential for the efficient use of space and the proper regulation of gene expression. Without proper chromatin packaging, cells can experience a range of problems, including aberrant gene…
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Retinoblastoma
Retinoblastoma is a rare type of cancer that affects the retina of the eye and is caused by mutations in the retinoblastoma (RB) gene. The RB gene plays a critical role in the regulation of cell growth and division, acting as a tumor suppressor by inhibiting the activity of other proteins that are important for…
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CT Scan Technique
CT (Computed Tomography) scan is a widely used medical imaging technique that produces detailed, cross-sectional images of the body using x-rays and computer technology. The technique uses x-ray detectors, reconstruction algorithms and dose management techniques to minimize the radiation dose to the patient while producing high-quality images. Specialized CT scans such as CT angiography, CT…
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Apoptotic pathways
Apoptosis is a crucial physiological process that plays a key role in the development and maintenance of tissue homeostasis, as well as in the response to cellular stress and damage. The process of apoptosis is regulated by a complex network of molecular pathways, including the extrinsic and intrinsic pathways. In the extrinsic pathway, signals from…
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Nucleus – Ultra structure
The nucleus is a vital organelle found in eukaryotic cells, which contains the genetic material of the cell in the form of DNA. It plays a significant role in the regulation of cell growth, division, and gene expression. The ultrastructure of the nucleus includes the nuclear envelope, nucleoplasm, and chromatin. The nuclear envelope surrounds the…
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The APC gene
APC genes are a group of tumor suppressor genes that play a crucial role in preventing the development of colon cancer. Mutations in APC genes can lead to the accumulation of beta-catenin in the cell, which can activate the Wnt signaling pathway and lead to uncontrolled cell growth and the development of tumors. Understanding the…
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Cryo Electron Microscopy (Cryo-EM)
Cryo-EM is a cutting-edge imaging technique used for studying the structure of biological macromolecules such as proteins and nucleic acids. By using a cryogenic electron microscope, researchers can capture high-resolution images of frozen, hydrated samples, preserving their native state and avoiding radiation damage. The sample preparation is a crucial step that involves rapid freezing of…
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Regulation of the Cell Cycle
he cell cycle is a crucial process in the growth and development of multicellular organisms, and its regulation is essential for maintaining proper cell function. Dysregulation of the cell cycle can lead to various diseases, including cancer, where cells divide uncontrollably. The regulation of the cell cycle is a complex process that involves a delicate…
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Cell Cycle and Its Regulation
The cell cycle is a fundamental process that is essential for the growth, development, and maintenance of all living organisms. It is a series of events that a cell undergoes to replicate and divide into two daughter cells. The cell cycle can be divided into two main stages: interphase and mitosis. Interphase is the period…
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The RAS gene
This text describes the significance of RAS gene mutations in the development and treatment of cancer. RAS genes play a vital role in regulating cell growth, and mutations in these genes can lead to the development of various cancers, including colorectal, lung, and pancreatic cancer. The three main isoforms of the RAS gene – KRAS,…
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Molecular Events of Amphibian Fertilization
Fertilization in amphibians is a fascinating process that involves a unique set of molecular events governing the successful fusion of male and female gametes. Unlike mammals, amphibians employ external fertilization, where the male releases sperm into the surrounding water, and the female lays her eggs. This process requires intricate cellular interactions, starting with chemotaxis and…
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Patch Clamp Technique
The patch clamp technique is a widely used electrophysiological method for studying ion channels in cell membranes. This technique involves using a micropipette to form a gigaohm seal with a cell membrane, allowing for the manipulation of the electrical potential across the membrane. There are four main types of patch clamp, each with their own…
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Micro and macro molecules
Micro and macro molecules are the building blocks of all living organisms. Micro molecules are small and simple in structure, while macro molecules are large and complex. They play crucial roles in metabolic processes, structural organization, and cellular processes. Understanding the properties and functions of these molecules is essential for understanding the complex processes that…
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Mitosis: Cell Division
Mitosis cell division is essential for the growth and repair of an organism. Mitosis involves four main stages: prophase, metaphase, anaphase, and telophase, followed by cytokinesis, the final stage where the cell physically divides into two identical daughter cells. The proper execution of mitosis is critical for the accurate replication and segregation of DNA and…
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Oncogenes and Tumor suppressor genes
The molecular genetics of cancer involves the study of the genetic and molecular changes that occur in cells as they become cancerous. This field of study has led to the identification of two important classes of genes involved in the development of cancer: oncogenes and tumor suppressor genes. Oncogenes promote cell growth and proliferation, while…
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