Podcast
Questions and Answers
What is a key factor that influences the functioning and fate of cells?
What is a key factor that influences the functioning and fate of cells?
- Signaling molecules (correct)
- Nutritional intake
- Genetic mutations
- Physical exercise
Cellular senescence results in improved regenerative capacity of the cell.
Cellular senescence results in improved regenerative capacity of the cell.
False (B)
What accumulates as a result of ER stress and contributes to aging?
What accumulates as a result of ER stress and contributes to aging?
oxidized, misfolded, cross-linked, or aggregated proteins
A network of molecular, cellular, and physiological maintenance creates a __________ capacity against damage.
A network of molecular, cellular, and physiological maintenance creates a __________ capacity against damage.
Match the following components of the immune system with their descriptions:
Match the following components of the immune system with their descriptions:
What happens when the load of senescent cells exceeds a certain threshold?
What happens when the load of senescent cells exceeds a certain threshold?
Aging leads to an increase in the buffering capacity against cellular damage.
Aging leads to an increase in the buffering capacity against cellular damage.
What is a consequence of the accumulation of damaged proteins in a cell?
What is a consequence of the accumulation of damaged proteins in a cell?
A combination of damaging processes can lead to __________, which is a state of malfunctioning cells.
A combination of damaging processes can lead to __________, which is a state of malfunctioning cells.
Which of the following processes is exacerbated by aging?
Which of the following processes is exacerbated by aging?
Flashcards
Cellular Aging
Cellular Aging
The process by which cells accumulate damage over time, leading to a decline in function. This damage can be caused by various factors, including oxidative stress, DNA damage, and telomere shortening.
Cellular Senescence
Cellular Senescence
A state in which cells stop dividing and enter a state of permanent growth arrest. This occurs due to damage accumulation and is characterized by changes in cellular function and morphology.
Senescence-Associated Secretory Phenotype (SASP)
Senescence-Associated Secretory Phenotype (SASP)
A group of secreted factors released by senescent cells that can influence the behavior of neighboring cells. These factors often contribute to inflammation and tissue dysfunction.
Threshold Theory of Senescent Cell Accumulation
Threshold Theory of Senescent Cell Accumulation
Signup and view all the flashcards
Innate Immune System
Innate Immune System
Signup and view all the flashcards
Adaptive Immune System
Adaptive Immune System
Signup and view all the flashcards
Homeostasis
Homeostasis
Signup and view all the flashcards
Reduced Stress Tolerance
Reduced Stress Tolerance
Signup and view all the flashcards
Maintenance and Repair Systems
Maintenance and Repair Systems
Signup and view all the flashcards
Stress Tolerance
Stress Tolerance
Signup and view all the flashcards
Study Notes
Cell Aging
- Aging is a biological process causing a decline in physical function due to accumulated cellular damage.
- Cell cultures show changes in cell appearance as they age.
- Cellular function and fate are influenced by neighboring cells and signaling molecules.
Organelles and their Functions
- Endoplasmic Reticulum (ER): Responsible for protein synthesis and folding, as well as membrane production.
- During aging, the ER loses its oxidative power, leading to faulty protein maturation (unfolded/misfolded proteins).
- ER homeostasis (balance of synthesis and breakdown of proteins) is disrupted during aging. ER stress results from an excess of unfolded/misfolded proteins.
- Factors contributing to ER stress can include genetic or environmental factors.
Lysosomes
- Lysosomes are important for cellular recycling by digesting waste materials.
- Autophagy is a recycling process where the ER isolates "garbage" into a bubble (autophagosome), which then fuses with a lysosome for degradation.
- Impaired lysosome function leads to the accumulation of faulty proteins, resulting in age-related neurodegenerative disorders like Alzheimer's and Parkinson's disease.
- Caloric restriction and Rapamycin treatment can maintain lysosome function.
Mitochondria
- Mitochondria are responsible for energy production via the conversion of oxygen and nutrients to ATP.
- Mitochondrial DNA (mtDNA) inherited maternally, is less protected from damage compared to nuclear DNA.
- Aging is associated with damage to mitochondria, causing mtDNA mutations, defective proteins, and increased free radical production which can worsen aging.
Cellular Senescence
- Senescence is a process where cells stop dividing due to stress in order to avoid damage and abnormal cell growth.
- Tumor suppressor proteins (p16, p53, p21) initiate the process to give time for DNA repair.
- Senescent cells produce the SASP which has both beneficial and detrimental actions. Healthy signaling allows cells to stop dividing once the cellular damage exceeds the threshold.
- Chronic senescent cell accumulation can lead to diseases and a decreased lifespan.
Immune System Aging
- The immune system has two major components: innate and adaptive.
- Innate immunity involves physical barriers and non-specialized cells, while adaptive immunity includes specialized cells (B and T cells).
- Aging affects both. Innate immune system shows decreased cell function.
- Adaptive immune system shows a decline in naïve T-cell and B-cell numbers, increased memory cells, reduced diversity of T-cell receptors and shrinkage of the thymus.
- Reduced immune function with age raises vulnerability to infections, and hinders vaccine efficacy.
- CMV (cytomegalovirus) has a chronic effect on the immune system with aging, which leads to reduced immune function.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
