Macromolecule Very large molecule, such as a protein A macromolecule is a very large molecule important to biological processes, such as a protein or nucleic acid. It is composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers. The most common macromolecules in biochemistry are biopolymers (nucleic acids, proteins, and carbohydrates) and large non-polymeric molecules such as lipids, nanogels and macrocycles.[1] Synthetic fibers and experimental materials such as carbon nanotubes[2][3] are also examples of macromolecules. Definition[edit] MacromoleculeLarge moleculeA molecule of high relative molecular mass, the structure of which essentiallycomprises the multiple repetition of units derived, actually or conceptually, frommolecules of low relative molecular mass. Usage of the term to describe large molecules varies among the disciplines. Because of their size, macromolecules are not conveniently described in terms of stoichiometry alone.
Biophysics Study of biological systems using methods from the physical sciences Molecular biophysics typically addresses biological questions similar to those in biochemistry and molecular biology, seeking to find the physical underpinnings of biomolecular phenomena. Scientists in this field conduct research concerned with understanding the interactions between the various systems of a cell, including the interactions between DNA, RNA and protein biosynthesis, as well as how these interactions are regulated. A great variety of techniques are used to answer these questions. Fluorescent imaging techniques, as well as electron microscopy, x-ray crystallography, NMR spectroscopy, atomic force microscopy (AFM) and small-angle scattering (SAS) both with X-rays and neutrons (SAXS/SANS) are often used to visualize structures of biological significance. Medical physics, a branch of biophysics, is any application of physics to medicine or healthcare, ranging from radiology to microscopy and nanomedicine.
Biochemistry Study of chemical processes in living organisms Much of biochemistry deals with the structures, bonding, functions, and interactions of biological macromolecules such as proteins, nucleic acids, carbohydrates, and lipids. They provide the structure of cells and perform many of the functions associated with life.[6] The chemistry of the cell also depends upon the reactions of small molecules and ions. These can be inorganic (for example, water and metal ions) or organic (for example, the amino acids, which are used to synthesize proteins).[7] The mechanisms used by cells to harness energy from their environment via chemical reactions are known as metabolism. History[edit] At its most comprehensive definition, biochemistry can be seen as a study of the components and composition of living things and how they come together to become life. Another significant historic event in biochemistry is the discovery of the gene, and its role in the transfer of information in the cell. Lipids[edit]
DNA Molecule that carries genetic information Deoxyribonucleic acid (;[1] DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids. The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides.[2][3] Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group. Within eukaryotic cells, DNA is organized into long structures called chromosomes. Properties DNA does not usually exist as a single strand, but instead as a pair of strands that are held tightly together.[9][12] These two long strands coil around each other, in the shape of a double helix. Nucleobase classification Grooves
Structural biology Study of molecular structures in biology Structural biology is a field that is many centuries old which, as defined by the Journal of Structural Biology, deals with structural analysis of living material (formed, composed of, and/or maintained and refined by living cells) at every level of organization. Early structural biologists throughout the 19th and early 20th centuries were primarily only able to study structures to the limit of the naked eye's visual acuity and through magnifying glasses and light microscopes. In the 20th century, a variety of experimental techniques were developed to examine the 3D structures of biological molecules. History[edit] In 1990, Richard Henderson produced the first three-dimensional, high resolution image of bacteriorhodopsin using cryogenic electron microscopy (cryo-EM).[15] Since then, cryo-EM has emerged as an increasingly popular technique to determine three-dimensional, high resolution structures of biological images.[16] Techniques[edit]
Protein Biomolecule consisting of chains of amino acid residues Once formed, proteins only exist for a certain period and are then degraded and recycled by the cell's machinery through the process of protein turnover. A protein's lifespan is measured in terms of its half-life and covers a wide range. They can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. History and etymology Proteins were recognized as a distinct class of biological molecules in the eighteenth century by Antoine Fourcroy and others, distinguished by the molecules' ability to coagulate or flocculate under treatments with heat or acid.[1] Noted examples at the time included albumin from egg whites, blood serum albumin, fibrin, and wheat gluten. The difficulty in purifying proteins in large quantities made them very difficult for early protein biochemists to study. The first protein to be sequenced was insulin, by Frederick Sanger, in 1949. Number of proteins encoded in genomes Classification
Amino acid Organic compounds containing amine and carboxylic groups Amino acids are organic compounds that contain both amino and carboxylic acid functional groups.[1] Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins.[2] Only these 22 appear in the genetic code of all life.[3][4] Amino acids are formally named by the IUPAC-IUBMB Joint Commission on Biochemical Nomenclature in terms of the fictitious "neutral" structure shown in the illustration. For example, the systematic name of alanine is 2-aminopropanoic acid, based on the formula CH3−CH(NH2)−COOH. The systematic names and formulas given refer to hypothetical forms in which amino groups are unprotonated and carboxyl groups are undissociated. History[edit] General structure[edit] Amino acids are known as 2-, alpha-, or α-amino acids..[20] They have the generic formula H2NCHRCOOH in most cases,[b] where R is an organic substituent known as a "side chain".[21] Chirality[edit]
Cell biology Scientific discipline that studies cells History[edit] Techniques[edit] Modern-day cell biology research looks at different ways to culture and manipulate cells outside of a living body to further research in human anatomy and physiology, and to derive medications. The techniques by which cells are studied have evolved. Cell culture: Utilizes rapidly growing cells on media which allows for a large amount of a specific cell type and an efficient way to study cells.[6]Fluorescence microscopy: Fluorescent markers such as GFP, are used to label a specific component of the cell. Cell classification and composition[edit] There are two fundamental classifications of cells: prokaryotic and eukaryotic. Prokaryotic cells[edit] A typical prokaryote cell. Flagella: A tail-like structure that helps the cell to move.[10]Ribosomes: Used for translation of RNA to protein.[10]Nucleoid: Area designated to hold all the genetic material in a circular structure.[10] Eukaryotic cells[edit] Processes[edit] [edit]
Nucleic acid Class of large biomolecules essential to all known life Nucleic acids RNA (left) and DNA (right). Nucleic acids are biopolymers, macromolecules, essential to all known forms of life.[1] They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. Nucleic acids are naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells and make up the genetic material. Strings of nucleotides are bonded to form helical backbones—typically, one for RNA, two for DNA—and assembled into chains of base-pairs selected from the five primary, or canonical, nucleobases, which are: adenine, cytosine, guanine, thymine, and uracil. History[edit] Nucleic acid was first discovered by Friedrich Miescher in 1869 at the University of Tübingen, Germany. Occurrence and nomenclature[edit] Molecular composition and size[edit] Nucleic acids are generally very large molecules. Topology[edit] Types[edit]
Histology Study of the microscopic anatomy of cells and tissues of plants and animals Biological tissues[edit] Animal tissue classification[edit] There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, and epithelial tissue.[5][9] All animal tissues are considered to be subtypes of these four principal tissue types (for example, blood is classified as connective tissue, since the blood cells are suspended in an extracellular matrix, the plasma).[9] Plant tissue classification[edit] For plants, the study of their tissues falls under the field of plant anatomy, with the following four main types: Medical histology[edit] Occupations[edit] The field of histology that includes the preparation of tissues for microscopic examination is known as histotechnology. Sample preparation[edit] Most histological samples need preparation before microscopic observation; these methods depend on the specimen and method of observation.[9] Fixation[edit] Selection and trimming[edit]