Cell Theory and Microscope Basics

Cell Theory

• All living organisms are made of one or more cells.
• The cell is the fundamental unit of life.
• All cells originate from pre-existing cells.

Microscope Parts

• Eyepiece (Ocular Lens): Magnifies the image.
• Objective Lenses: Provide varying magnifications (e.g., low, medium, high).
• Stage: Supports the slide.
• Stage Clips: Secure the slide in place.
• Light Source: Illuminates the specimen.
• Condenser: Focuses light onto the specimen.
• Coarse Adjustment Knob: Moves the stage for rough focusing.
• Fine Adjustment Knob: Fine-tunes the focus.

Microscope Magnification

• The total magnification is calculated by multiplying the eyepiece magnification by the objective magnification.

Monocular vs. Stereo Microscopes

• Monocular Microscope:
  • It has a single eyepiece.
  • It provides higher magnification.
  • It's used for viewing thin specimens.
• Stereo Microscope:
  • It has two eyepieces.
  • It provides lower magnification.
  • It offers a 3D view.
  • It's used for larger or opaque specimens.

Light vs. Electron Microscopes

• Light Microscope:
  • Uses light to magnify specimens.
  • Can be used to observe live cells.
  • Offers lower magnification (up to 1000x).
• Electron Microscope:
  • Uses electrons to magnify specimens.
  • Provides much higher magnification (up to 2 million x).
  • Can only be used to observe dead specimens.

Unicellular vs. Multicellular Organisms

• Unicellular Organisms: Consists of a single cell (e.g., bacteria, amoeba).
• Multicellular Organisms: Comprised of multiple cells (e.g., humans, plants).

Generalized Plant and Animal Cells

• Nucleus: Controls cellular activities.
• Cytoplasm: Site of metabolic reactions.
• Cell Membrane: Regulates the entry and exit of substances.
• Cell Wall (plant): Provides structural support.
• Chloroplasts (plant): Site of photosynthesis.
• Mitochondria: Site of cellular respiration.
• Vacuoles: Store nutrients and waste.

Venn Diagram of Plant and Animal Cells

• Similarities: Both have cell membranes, cytoplasm, and organelles (like mitochondria).
• Differences: Plant cells have cell walls and chloroplasts; animal cells do not.

Cellular Respiration and Photosynthesis

• Cellular Respiration: Converts glucose and oxygen into energy (ATP), carbon dioxide, and water.
• Photosynthesis: Converts sunlight, carbon dioxide, and water into glucose and oxygen.

Word Equations

• Cellular Respiration:
  • Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)
• Photosynthesis:
  • Carbon Dioxide + Water + Light → Glucose + Oxygen

Mitochondria and Cellular Respiration

• Mitochondria are known as the powerhouse of the cell.
• They are responsible for producing energy (ATP) through cellular respiration.

Energy Requirements and Respiration Rate

• Increased energy demands (e.g., muscle cells during exercise) result in an increased rate of cellular respiration.

Specialized Cells

• Red Blood Cells: Transport oxygen.
• Nerve Cells: Transmit signals.
• Muscle Cells: Enable movement.

Stem Cells in Medicine

• Stem cells possess the potential to develop into various cell types.
• They offer promising possibilities for regenerative medicine and disease treatments.

Skin Diagram

• Epidermis: Outer layer of the skin.
• Dermis: Middle layer containing blood vessels and nerves.
• Hypodermis: Innermost layer connecting the skin to underlying tissues.