Key Concepts from the Lecture on Cell Functions and Virus Interaction

Overview

• This lecture discusses how cells interact with viruses, focusing on the process when a virus enters a human cell and how the cell responds to this invasion.

Structure of Cells

• Cell Membrane:
  • Flexible layer made of fats and proteins.
  • Semipermeable, allowing selective passage of substances.
  • Contains projections for adherence and nutrient binding.
• Cell Wall:
  • Only found in plant cells.
  • Made of rigid cellulose for structural support.

Virus Invasion and Cell Response

• Entry of Virus:
  • Virus attaches to cell membrane projection and is brought inside the cell.
• Recognition and Defense:
  • Special enzymes inside the cell chop the virus into pieces.
  • A piece is sent back to the membrane to warn neighboring cells.

Antibody Production

• Nucleus:

  • Contains DNA with instructions for making antibodies.
  • Enzymes create messenger RNA (mRNA) from DNA instructions.

• Ribosomes and Endoplasmic Reticulum:

  • Ribosomes read mRNA and link amino acids to form antibodies.

• Golgi Apparatus:

  • Packages antibodies for delivery outside the cell.
  • Fuses with cell membrane to eject antibodies.

Energy Production

• Mitochondria:
  • Converts oxygen and food electrons into water molecules and ATP, the cell's energy source.
• Plant Cells and Chloroplasts:
  • Use photosynthesis to create oxygen and sugar from carbon dioxide, water, and sunlight.

Summary

• The cooperation of all cell parts is essential for survival.
• Approximately 37 trillion cells exist in the human body, all working together to maintain bodily functions.