Accumulating evidence now indicates that the sum of the deleterious free radical reactions going on con- tinuously throughout the cells and tissues constitutes the aging process or is a major contributor to it. In mammalian systems the free radical reactions are largely those involving oxygen..
What are the 3 biochemical triggers that contribute to aging?
For many of the changes taking place in the body during aging, three factors are important: inflammation, immune aging and senescence (cellular aging, biological aging). Senescence is an irreversible form of long-term cell-cycle arrest, caused by excessive intracellular or extracellular stress or damage..
What are the biochemical markers of aging?
The main mechanisms identified as potential biomarkers of aging are DNA methylation, loss of histones, and histone modification. The uses for biomarkers of aging are ubiquitous and identifying a physical parameter of biological aging would allow humans to determine our true age, mortality, and morbidity..
What biochemical changes occur in aging?
The most important one is mTORC1 that becomes hyperactive in cells that undergo aging. Other significant changes with age are lysosome accumulation, impaired autophagy, and mitophagy..
What causes aging biochemistry?
Oxidative damage. One major theory sees our metabolism as the cause of our aging. According to this theory, aging is a by-product of normal metabolism; no mutations are required. About 2–3% of the oxygen atoms taken up by the mitochondria are reduced insufficiently to reactive oxygen species (ROS)..
What is aging in biochemistry?
aging, progressive physiological changes in an organism that lead to senescence, or a decline of biological functions and of the organism's ability to adapt to metabolic stress..
What is the biochemical basis of aging?
Aging is the result of random events from environment, not genetically programmed. Superoxide anion (O2-) is primarily form of oxidant by products produced in the body as a consequence of normal aerobic metabolism. (Pamplona R, Barja G, 2000)..
What is the biochemical phenomenon of ageing?
The mitochondrial theory of aging was based on the idea that there exists within mitochondria a vicious oxidation cycle, in which the mutation of mitochondrial DNA impairs the function of proteins in the organelle's respiration machinery, thereby enhancing the production of DNA-damaging oxygen radicals..
What is the biochemistry of aging?
Cellular and organ metabolism affects organismal lifespan. Aging is characterized by increased risks for metabolic disorders, with age-associated degenerative diseases exhibiting varying degrees of mitochondrial dysfunction..
Biological aging is characterized by progressive age-changes in metabolism and physicochemical properties of cells, leading to impaired self-regulation, regeneration, and to structural changes and functional tissues and organs.
For many diseases, the most important risk factor is biological age, meaning that if your cells are older, they are more susceptible to a variety of diseases, such as: Lung disease.
For many of the changes taking place in the body during aging, three factors are important: inflammation, immune aging and senescence (cellular aging, biological aging). Senescence is an irreversible form of long-term cell-cycle arrest, caused by excessive intracellular or extracellular stress or damage.
There is much debate among researchers about the mechanisms that contribute to the ageing process. However, it is widely accepted that damage to genetic material, cells and tissues that accumulates with age and cannot be repaired by the body is the cause of the loss of function associated with ageing.
Aging is the consequence of the accumulation of damage by deleterious oxidation in bimolecular caused by the high reactivity of the ROS produced in cells as a result of the necessary use of oxygen. Genetic theory: Aging is the result of a purposeful program driven by the genes.
Although philosophers and scientists have long been interested in the aging process, general interest in this fascinating and highly important topic was
The biochemistry of agingAuthorAffiliation. 1 Department of Pathology, University of Utah School of Medicine, Salt Lake City, USA.
Biological theories of aging
Aging has many facets. Hence, there are a number of theories, each of which may explain one or more aspects of aging. There is, however, no single theory that explains all of the phenomena of aging.
Overview
aging, progressive physiological changes in an organism that lead to senescence, or a decline of biological functions and of the organism’s ability to adapt to metabolic stress.
Biochemistry of aging
Type of biomarkers
Biomarkers of aging are biomarkers that could predict functional capacity at some later age better than chronological age. Stated another way, biomarkers of aging would give the true biological age, which may be different from the chronological age.
Hypothesis that aging is caused by accumulated DNA damage
The DNA damage theory of aging proposes that aging is a consequence of unrepaired accumulation of naturally occurring DNA damage. Damage in this context is a DNA alteration that has an abnormal structure. Although both mitochondrial and nuclear DNA damage can contribute to aging, nuclear DNA is the main subject of this analysis. Nuclear DNA damage can contribute to aging either indirectly or directly.
Study of the evolutionary development of ageing processes
Enquiry into the evolution of ageing, or aging, aims to explain why a detrimental process such as ageing would evolve, and why there is so much variability in the lifespans of organisms. The classical theories of evolution suggest that environmental factors, such as predation, accidents, disease, and/or starvation, ensure that most organisms living in natural settings will not live until old age, and so there will be very little pressure to conserve genetic changes that increase longevity. Natural selection will instead strongly favor genes which ensure early maturation and rapid reproduction, and the selection for genetic traits which promote molecular and cellular self-maintenance will decline with age for most organisms.
Free-radical aging theory
The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. A free radical is any atom or molecule that has a single unpaired electron in an outer shell. While a few free radicals such as melanin are not chemically reactive, most biologically relevant free radicals are highly reactive. For most biological structures, free radical damage is closely associated with oxidative damage. Antioxidants are reducing agents, and limit oxidative damage to biological structures by passivating them from free radicals.
Biomarkers of aging are biomarkers that could predict functional
Type of biomarkers
Biomarkers of aging are biomarkers that could predict functional capacity at some later age better than chronological age. Stated another way, biomarkers of aging would give the true biological age, which may be different from the chronological age.
Hypothesis that aging is caused by accumulated DNA damage
The DNA damage theory of aging proposes that aging is a consequence of unrepaired accumulation of naturally occurring DNA damage. Damage in this context is a DNA alteration that has an abnormal structure. Although both mitochondrial and nuclear DNA damage can contribute to aging, nuclear DNA is the main subject of this analysis. Nuclear DNA damage can contribute to aging either indirectly or directly.
Study of the evolutionary development of ageing processes
Enquiry into the evolution of ageing, or aging, aims to explain why a detrimental process such as ageing would evolve, and why there is so much variability in the lifespans of organisms. The classical theories of evolution suggest that environmental factors, such as predation, accidents, disease, and/or starvation, ensure that most organisms living in natural settings will not live until old age, and so there will be very little pressure to conserve genetic changes that increase longevity. Natural selection will instead strongly favor genes which ensure early maturation and rapid reproduction, and the selection for genetic traits which promote molecular and cellular self-maintenance will decline with age for most organisms.
Free-radical aging theory
The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. A free radical is any atom or molecule that has a single unpaired electron in an outer shell. While a few free radicals such as melanin are not chemically reactive, most biologically relevant free radicals are highly reactive. For most biological structures, free radical damage is closely associated with oxidative damage. Antioxidants are reducing agents, and limit oxidative damage to biological structures by passivating them from free radicals.
