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CoRR Hypothesis
The CoRR hypothesis states that the location of genetic information in cytoplasmic organelles permits regulation of its expression by the reduction-oxidation ("redox") state of its gene products. CoRR is short for "co-location for redox regulation", itself a shortened form of "co-location (of gene and gene product) for (evolutionary) continuity of redox regulation of gene expression". CoRR was put forward explicitly in 1993 in a paper in the '' Journal of Theoretical Biology'' with the title "Control of gene expression by redox potential and the requirement for chloroplast and mitochondrial genomes". The central concept had been outlined in a review of 1992. The term CoRR was introduced in 2003 in a paper in '' Philosophical Transactions of the Royal Society'' entitled "The function of genomes in bioenergetic organelles". The problem Chloroplasts and mitochondria Chloroplasts and mitochondria are energy-converting organelles in the cytoplasm of eukaryotic cells. Chloropla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Information
A nucleic acid sequence is a succession of Nucleobase, bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nucleotides. By convention, sequences are usually presented from the Directionality (molecular biology), 5' end to the 3' end. For DNA, with its double helix, there are two possible directions for the notated sequence; of these two, the Sense (molecular biology), sense strand is used. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the Biomolecular structure#Primary structure, primary structure. The sequence represents genetic information. Biological deoxyribonucleic acid represents the information which directs the functions of an organism. Nucleic acids also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioenergetics
Bioenergetics is a field in biochemistry and cell biology that concerns energy flow through living systems. This is an active area of biological research that includes the study of the transformation of energy in living organisms and the study of thousands of different cellular processes such as cellular respiration and the many other metabolic and enzymatic processes that lead to production and utilization of energy in forms such as adenosine triphosphate (ATP) molecules. Nelson, David L., Cox, Michael M. ''Lehninger: Principles of Biochemistry.'' New York: W.H. Freeman and Company, 2013. Sixth ed., pg. 27. That is, the goal of bioenergetics is to describe how living organisms acquire and transform energy in order to perform biological work. Nelson, David L., Cox, Michael M. ''Lehninger: Principles of Biochemistry.'' New York: W.H. Freeman and Company, 2013. Sixth ed., pg. 24. The study of metabolic pathways is thus essential to bioenergetics. Overview Bioenergetics is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Selection
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with selective breeding, artificial selection, which is intentional, whereas natural selection is not. Genetic diversity, Variation of traits, both Genotype, genotypic and phenotypic, exists within all populations of organisms. However, some traits are more likely to facilitate survival and reproductive success. Thus, these traits are passed the next generation. These traits can also become more Allele frequency, common within a population if the environment that favours these traits remains fixed. If new traits become more favoured due to changes in a specific Ecological niche, niche, microevolution occurs. If new traits become more favoured due to changes in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up quark, up and down quark, down quarks. Electrons are extremely lightweight particles that orbit the positively charged atomic nucleus, nucleus of atoms. Their negative charge is balanced by the positive charge of protons in the nucleus, giving atoms their overall electric charge#Charge neutrality, neutral charge. Ordinary matter is composed of atoms, each consisting of a positively charged nucleus surrounded by a number of orbiting electrons equal to the number of protons. The configuration and energy levels of these orbiting electrons determine the chemical properties of an atom. Electrons are bound to the nucleus to different degrees. The outermost or valence electron, valence electrons are the least tightly bound and are responsible for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genes
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Nucleus
The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, no nuclei, and a few others including osteoclasts have Multinucleate, many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long strands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are Nuclear organization, structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosymbiont
An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualism (biology), mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside Coral reef, reef-building corals, and bacterial endosymbionts that provide essential nutrients to insects. Endosymbiosis played key roles in the development of eukaryotes and plants. Roughly 2.2 billion years ago an archaeon absorbed a bacterium through phagocytosis, that eventually became the mitochondria that provide energy to almost all living Eukaryote, eukaryotic cells. Approximately 1 billion years ago, some of those cells absorbed cyanobacteria that eventually became chloroplasts, organelles that produce energy from sunlight. Approximately 100 million years ago, a lineage of amoeba in the genus ''Paulinella'' independently engulfed a cyanobacterium that evolved to be f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. The process of evolution has given rise to biodiversity at every level of biological organisation. The scientific theory of evolution by natural selection was conceived independently by two British naturalists, Charles Darwin and Alfred Russel Wallace, in the mid-19th century as an explanation for why organisms are adapted to their physical and biological environments. The theory was first set out in detail in Darwin's book ''On the Origin of Species''. Evolution by natural selection is established by observable facts about living organisms: (1) more offspring are often produced than can possibly survive; (2) phenotypic variatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maternal Inheritance
Non-Mendelian inheritance is any pattern in which traits do not segregate in accordance with Mendel's laws. These laws describe the inheritance of traits linked to single genes on chromosomes in the nucleus. In Mendelian inheritance, each parent contributes one of two possible alleles for a trait. If the genotypes of both parents in a genetic cross are known, Mendel's laws can be used to determine the distribution of phenotypes expected for the population of offspring. There are several situations in which the proportions of phenotypes observed in the progeny do not match the predicted values. Certain inherited diseases and their presentation display non-Mendelian patterns, complicating making predictions from family history. Types Incomplete dominance, codominance, multiple alleles, and polygenic traits follow Mendel's laws, display Mendelian inheritance, and are explained as extensions of Mendel's laws. Incomplete dominance In cases of intermediate inheritance due to inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendelian
Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularized by William Bateson. These principles were initially controversial. When Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics. Ronald Fisher combined these ideas with the theory of natural selection in his 1930 book '' The Genetical Theory of Natural Selection'', putting evolution onto a mathematical footing and forming the basis for population genetics within the modern evolutionary synthesis. History The principles of Mendelian inheritance were named for and first derived by Gregor Johann Mendel, a nineteenth-century Moravian monk who formulated his ideas after conducting simple hybridization experiments with pea plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosol
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells ( intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into many compartments. In the eukaryotic cell, the cytosol is surrounded by the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles. In prokaryotes, most of the chemical reactions of metabolism take place in the cytosol, while a few take place in membranes or in the periplasmic space. In eukaryotes, while many metabolic pathways still occur in the cytosol, others take place within organelles. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and proper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosomes
A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most important of these proteins are the histones. Aided by chaperone proteins, the histones bind to and condense the DNA molecule to maintain its integrity. These eukaryotic chromosomes display a complex three-dimensional structure that has a significant role in transcriptional regulation. Normally, chromosomes are visible under a light microscope only during the metaphase of cell division, where all chromosomes are aligned in the center of the cell in their condensed form. Before this stage occurs, each chromosome is duplicated ( S phase), and the two copies are joined by a centromere—resulting in either an X-shaped structure if the centromere is located equatorially, or a two-armed structure if the centromere is located distally; the joined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
