be less efficient. Cells in highly oxidative organs have the most damaged, then the functioning of the whole cell is impaired and it
becomes susceptible to Apoptosis.
DNA that is repaired is considered a deviation countering mechanism for aging.
What can damage DNA? UV light, chemical, oxidation, etc…
The 4 things that repair DNA: Base excision repair, nucleotide excision repair, mismatch repair and repair of strands
Sometimes error can be missed and it’s ok, it’s not that severe, but if it’s really severe this can lead to apoptosis.
Molecular/cellular theories of aging.
Oxidation : Free radicals is also known as reactive oxygen species (ROS).
• it’s a molecule that is created during the oxidative process in cells.
• why are they dangerous: they have an unpaired electron and they are unstable and highly chemically reactive and they
could interfere with other functions of other molecules in the cell like DNA replication, protein synthesis, etc…
•can cause proteins to unfold and also interferes with DNA and its transcription process.
But the cells also produce antioxidants like superoxide dismutase (SOD)
The concentration of free radicals (cell damage) increases with age because : more free radicals in aging cells, decrease
ability for cell to create antioxidents, and repair mechanisms in cells are less efficient.
SOD IS HIGHER IN CELLS OF CENTENARIANS.
Lipofuscin : when cells that are aging produces waste.
• A dark mixture.
•disposed through Liposomal enzymes , but in older people, this processes is impaired (damaged)
•increases with ages, can be found in many cell types
•reduce caloric restriction appears to decrease the rate of production of lipofusion
Heat Shock protein (HSP)s: a cellular repair mechanism=aging decelerator
•First identified in plant cells undergoing heat-related stress. That’s why they are called this
•protect cells from STERSSORS (radiation, oxidation, infection)
•Found in every organism and cells (bacteria and humans)
• promotes healthy cell growth and proliferation.
•Also called MOLECULAR CHAPERONS (assist in protein synthesis and repair)
Different types of HSP’s that has different functions.
Small HSP’s: protect cells from stress
other refold damaged proteins