Lecture 2 Cell Structure and Functions

• What is the scientific study of aging called?

  Gerontology
• What happens to the body's homeostatic responses during aging?

  They undergo progressive alterations
• What observable changes occur in cells as they age?

  Changes in structure and function
• How do aging cells differ in their ability to divide?

  They become less able to divide
• What accumulates inside aging cells?

  Pigments and fatty substances
• What happens to the plasma membrane as cells age?

  It has increased fatty acids
• How does aging affect the fluidity of the plasma membrane?

  It decreases the fluidity
• What is reduced due to changes in the plasma membrane?

  Transportation of ions and nutrients
• What forms between sulfur atoms on DNA as cells age?

  Cross-linkages
• How does DNA condensation affect RNA synthesis?

  It decreases RNA synthesis
• What happens to the cytoplasm volume as cells age?

  The volume increases
• Where do enzymes that synthesize DNA move as cells age?

  From the nucleus to the cytoplasm
• What happens to ribosomal RNA as cells age?

  It decreases in amount
• What is the effect of decreased ribosomal RNA on protein synthesis?

  It decreases protein synthesis
• How does the number of mitochondria change as cells age?

  It decreases
• What is the consequence of fewer mitochondria in aging cells?

  Reduced energy production
• How do lysosomes change as cells age?

  They become less able to break down waste
• What is the result of lysosomal changes in aging cells?

  Build-up of waste within the cell