Graduate
  1. Physical Chemistry  1.1. Thermodynamics  1.1.1. Laws of Thermodynamics  1.1.2. Enthalpy and heat capacity  1.1.3. Entropy and free energy  1.1.4. Phase Equilibrium  1.1.5. Statistical thermodynamics  1.1.6. Thermodynamic cycle  1.1.7. Fugacity and activity  1.2. Quantum Chemistry  1.2.1. Principles of quantum mechanics  1.2.2. Schrödinger Equation  1.2.3. Particle in a box  1.2.4. Operators and eigenvalues  1.2.5. Atomic orbitals  1.2.6. Molecular orbital theory  1.2.7. Perturbation theory  1.2.8. Valence bond theory  1.2.9. Hybridization and chemical bonding  1.3. Chemical kinetics  1.3.1. Rate laws and reaction mechanisms  1.3.2. Collision theory  1.3.3. Transition state theory  1.3.4. Enzyme Kinetics  1.3.5. Chain Reactions and Polymerization  1.3.6. Photochemical reactions  1.4. Statistical mechanics  1.4.1. Partitioning functions  1.4.2. Molecular distribution functions  1.4.3. Boltzmann Distribution  1.4.4. Bose–Einstein and Fermi–Dirac statistics  1.5. Spectroscopy  1.5.1. Rotational Spectroscopy  1.5.2. Vibrational Spectroscopy  1.5.3. Electronic Spectroscopy  1.5.4. Nuclear magnetic resonance spectroscopy  1.5.5. Mass Spectrometry  1.5.6. Raman Spectroscopy  1.5.7. Electron paramagnetic resonance spectroscopy  1.6. Surface and colloidal chemistry  1.6.1. Absorption isotherm  1.6.2. Surface tension and wetting  1.6.3. Colloidal Stability  1.6.4. Catalysis  1.6.5. Emulsions and micelles  1.7. Electrochemistry  1.7.1. Nernst equation  1.7.2. Electrochemical cells  1.7.3. Conductivity and mobility  1.7.4. War  1.7.5. Fuel cells  1.7.6. Electrolysis
  2. Organic chemistry  2.1. Reaction mechanism  2.1.1. Nucleophilic substitution reactions  2.1.2. Electrophilic addition reactions  2.1.3. Elimination reactions  2.1.4. Rearrangement reactions  2.1.5. Radical reactions  2.1.6. Pericyclic reactions  2.2. Spectroscopy and structural determination  2.2.1. UV-Vis Spectroscopy  2.2.2. IR Spectroscopy  2.2.3. NMR Spectroscopy  2.2.4. Mass Spectrometry  2.2.5. X-ray crystallography  2.3. Stereoscopic  2.3.1. Chirality and optical activity  2.3.2. Structural analysis  2.3.3. Geometrical isomerism  2.3.4. Dynamic Stereochemistry  2.4. Organometallic Chemistry  2.4.1. Organolithium and organomagnesium reagents  2.4.2. Palladium-catalyzed cross-coupling reactions  2.4.3. Transition Metal Complexes  2.4.4. Metal–carbon bond  2.5. Polymer chemistry  2.5.1. Polymerization mechanism  2.5.2. Polymer Characteristics  2.5.3. Biodegradable Polymer  2.5.4. Conducting polymer  2.5.5. Supramolecular polymers  2.6. Medicinal chemistry  2.6.1. Drug design and development  2.6.2. Pharmacokinetics and pharmacodynamics  2.6.3. Structure-activity relationships  2.6.4. Molecular docking and drug screening
  3. Inorganic chemistry  3.1. Coordination chemistry  3.1.1. Crystal field theory  3.1.2. Ligand field theory  3.1.3. Spectrochemical Series  3.1.4. Chelation and stability  3.2. Organometallic Chemistry  3.2.1. Metal Carbonyls  3.2.2. Catalysis by organometallic complexes  3.2.3. Metallocenes  3.3. Bio-inorganic chemistry  3.3.1. Metalloproteins and enzymes  3.3.2. The role of metals in biological systems  3.3.3. Metal ion transport and storage  3.4. Solid state chemistry  3.4.1. Crystal Structures  3.4.2. Band theory of solids  3.4.3. Superconductors  3.4.4. Defects in the crystal  3.5. Lanthanides and Actinides  3.5.1. Electronic configuration in lanthanides and actinides  3.5.2. Coordination chemistry of the lanthanides  3.5.3. Magnetic Properties of Lanthanides
  4. Analytical chemistry  4.1. Chromatography  4.1.1. Gas Chromatography  4.1.2. High Performance Liquid Chromatography  4.1.3. Thin Layer Chromatography  4.2. Spectroscopic Techniques  4.2.1. Atomic absorption spectroscopy  4.2.2. X-ray diffraction  4.2.3. Inductively coupled plasma spectroscopy  4.3. Electroanalytical methods  4.3.1. Potentiometry  4.3.2. Voltammetry  4.3.3. Colometry  4.4. Mass Spectrometry  4.4.1. Ionization Technique  4.4.2. Fragmentation Pattern  4.5. Chemometrics  4.5.1. Multidisciplinary analysis  4.5.2. Machine Learning in Chemistry
  5. Theoretical and Computational Chemistry  5.1. Molecular dynamics simulation  5.1.1. Force fields and energy minimization  5.1.2. Monte Carlo simulation in molecular dynamics simulations  5.2. Quantum chemical methods  5.2.1. Hartree–Fock theory  5.2.2. Density functional theory  5.2.3. Semi-empirical methods  5.3. Computational drug design  5.3.1. Molecular Docking  5.3.2. QSAR Modeling  5.3.3. Virtual Screening
  6. Biochemistry  6.1. Enzyme Kinetics  6.1.1. Michaelis-Menten kinetics  6.1.2. Inhibition mechanism  6.2. Metabolism and Bioenergetics  6.2.1. Glycolysis  6.2.2. Citric acid cycle  6.2.3. Electron transport chain  6.3. molecular Biology  6.3.1. DNA replication and repair  6.3.2. Protein synthesis  6.3.3. Gene Regulation  6.4. Structural Biochemistry  6.4.1. Protein Folding  6.4.2. Membrane Biophysics
  7. Environmental Chemistry  7.1. Atmospheric Chemistry  7.1.1. Greenhouse gases  7.1.2. Ozone depletion  7.1.3. Air pollutants and smoke  7.2. Water Chemistry  7.2.1. pH and water hardness  7.2.2. Wastewater treatment  7.2.3. Aquatic Chemistry  7.3. Soil Chemistry  7.3.1. Heavy metal contamination  7.3.2. Soil pH and Buffering  7.3.3. Nutrient cycling  7.4. Toxicology and Chemical Safety  7.4.1. Toxicokinetics  7.4.2. Risk Assessment in Toxicology and Chemical Safety in Environmental Chemistry  7.4.3. Effects of pollutants on the environment

Graduate → Biochemistry ↓


molecular Biology


Molecular biology is a branch of science concerned with biological activities at the molecular level. The field overlaps with other areas of biology and chemistry, especially genetics and biochemistry. Molecular biology focuses primarily on understanding the interactions between the various systems of a cell, including the interactions between DNA , RNA, and protein synthesis , as well as learning how these interactions are regulated.

Understanding DNA structure

At the core of molecular biology is understanding and identifying how different biological molecules affect cell pathways. DNA, or deoxyribonucleic acid, is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses. Here is a very simplified model of the structure of DNA:

5' end 3' end Yes C A Tea

In the diagram above, the blue and red lines represent two strands of DNA. The lines connecting the strands represent hydrogen bonds between complementary bases: guanine (G) pairs with cytosine (C), and adenine (A) pairs with thymine (T). These pairs are known as base pairs.

The DNA structure forms a double helix, as discovered by Watson and Crick in 1953. The importance of the double helix is that it makes DNA incredibly stable, while also being compact enough to fit into the cell nucleus.

Replication: duplication of DNA

DNA replication is the biological process by which a cell copies its DNA, which is necessary for cell division. This process ensures that each new cell receives a copy of the DNA. Here is an example using a simple DNA sequence:

Original DNA strand: 5'-GCTAGC-3'
    Complementary strand: 3'-CGATCG-5'

During DNA replication, enzymes called helicases unwind the double helix at the origin of replication, making each strand available to serve as a template for a new strand. Another enzyme, DNA polymerase, then synthesizes the complementary DNA strand by adding nucleotides to the growing chain. The result is two DNA molecules identical to the original DNA molecule.

Transcription and RNA

Transcription is the process through which a segment of DNA is copied into RNA (ribonucleic acid) by the enzyme RNA polymerase. During this process, the DNA sequence of a gene is transcribed to form an RNA molecule. This mRNA (messenger RNA) will later serve as a template for protein synthesis.

DNA template strand mRNA Strand 5'-OGQA-3' 3'-TACGAT-5'

In the diagram, the top blue strand represents the DNA template strand, while the dashed green line represents the mRNA strand synthesized from it. Note that in RNA, thymine (T) is replaced by uracil (U).

Translation and protein synthesis

Translation is the process in which cellular ribosomes make proteins using mRNA produced during transcription. The mRNA is decoded by the ribosomes to form a specific polypeptide, or chain of amino acids.

mRNA: 5'-AUGCUAGCU-3'
    Polypeptide: methionine-leucine-alanine

In this code, each triplet of nucleotides is called a codon, and each codon corresponds to a specific amino acid as directed by the genetic code. For example, the mRNA sequence `AUG` codes for methionine, which is often the starting codon for translation.

Gene expression and regulation

Gene expression is a tightly regulated process that allows a cell to respond dynamically to its environment. This regulation occurs at many levels, from transcriptional control to post-translational modification of proteins. Understanding the regulation of gene expression is important for studying molecular biology.

Complex networks of genes are regulated by signaling pathways that allow cells to interpret and respond to various environmental stimuli. For example, hormonal signals can activate proteins that bind to DNA and affect the rate of transcription for specific genes, affecting the amount of protein produced.

Mutations and genetic variability

Mutations are changes in the genetic material and can affect the structure and amount of proteins produced. They can be caused by errors during DNA replication or by environmental factors such as UV radiation and chemical exposure. The outcome of mutations varies, with potential results ranging from benign to harmful effects.

For example, genetic disorders such as cystic fibrosis are caused by harmful mutations in specific genes, while mutations can also be beneficial, leading to increased survival and reproduction in a given environment.

Research techniques in molecular biology

Research in molecular biology uses many techniques to study cellular structures and functions. Here are some common techniques:

  • Polymerase chain reaction (PCR): A method for amplifying DNA sequences, making it easier to study small samples.
  • Gel electrophoresis: A technique used to separate DNA fragments by size by applying an electric field to a gel matrix.
  • CRISPR-Cas9: a revolutionary gene-editing tool that allows precise modifications to DNA.
  • DNA sequencing: Techniques such as Sanger sequencing and next-generation sequencing reveal the sequence of nucleotides in DNA.

Applications of molecular biology

Molecular biology has wide implications and applications in medicine, agriculture, biotechnology, and other fields. It allows the development of genetic therapies that target diseases at the DNA level, the production of recombinant proteins, and advances in personalized medicine.

In agriculture, genetic modification can produce crops with improved properties, such as drought resistance, pest resistance, or greater nutritional value.

The impact of molecular biology on science and everyday life is profound and continues to grow as technology advances and our understanding of molecular processes deepens.

Conclusion

Molecular biology, as a fundamental aspect of modern biology and chemistry, provides insights into the essence of life. It enables scientists to analyze cellular processes at the molecular level and develop interventions for a range of applications from disease treatment to increasing agricultural production. As research progresses, integration between molecular biology and fields such as synthetic biology and genomics will likely lead to even more exciting developments and technologies.


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molecular Biology

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