Genetics:Cell

• Cell history:

  • 1600s: Anton Van Leeuwenhoek and Robert Hooke made significant contributions
  • 1800s: Robert Brown discovered the nucleus
  • Cell Theory:

  1. All living things are made of cells

  • Schleiden: all plants are made of cells
  • Schwann: all animals are made of cells

  2. Cells are the basic (smallest) unit of life and carry out the 8 life functions

  3. Cells can only come from preexisting cells (Virchow)
• Viruses:

  • Have no organelles
  • Contain DNA or RNA in a protein head
  • Use host cell’s machinery for replication
  • Can't replicate without a host cell
• Cell Types:

  • Prokaryotic Type:
  • Simple structure
  • Ancient (3 billion years old)
  • Bacteria only
  • Eukaryotic Type:
  • Complex structure
  • Relatively recent (1.3 billion years old)
  • Found in plants and animals
• Eukaryotic Cells:

  • Animal Cell Structure:
  • Nucleus: cellular control center
  • Rough Endoplasmic Reticulum: network of channels for protein transport
  • Ribosomes: synthesis proteins
  • Mitochondria: powerhouse of the cell, performs cellular respiration
  • Lysosome: cellular digestion function
• Cytoskeleton:

  • Microtubules, Intermediate Filaments, Microfilaments
  • Provide cell shape, organelle anchors, and molecular motors
  • Involved in cellular contraction and movement
• Plastids:

  • Found only in photosynthetic cells
  • Types include Leucoplasts, Chromoplasts, and Chloroplasts
  • Site of photosynthesis and have own DNA
• Cilia and Flagella:

  • Cilia: short, numerous, involved in cell movement
  • Flagella: long, usually 1 or 2 per cell, involved in cell movement
• Plasma (cell) membrane:

  • Selectively permeable
  • Components include phospholipids, cholesterol, proteins, and carbohydrates
• Endomembrane System:

  • Includes the Endoplasmic Reticulum, Golgi Apparatus, and transport vesicles
• Cell Junctions:

  • Tight Junctions: fused membranes for material transport
  • Gap Junctions: cytoplasm of cells connected through channels
• Active Transport:

  • Requires energy (ATP)
  • Moves materials against a concentration gradient
• Cells and Living Creatures:

  • Unicellular creatures: Protozoa, Bacteria, Algae
  • Colonial organisms: individual cells loosely connected
  • True multicellular organisms: many cells performing specialized functions
• Mitochondria are responsible for energy production through cellular respiration.
• The nucleus is the largest organelle, containing DNA.
• Ribosomes synthesize proteins using information from mRNA.
• Chloroplasts contain chlorophyll and are involved in photosynthesis.
• Lysosomes contain digestive enzymes that break down waste products within the cell.
• Ribosomes synthesize proteins using information from DNA or RNA.
• Ribosomes synthesize proteins using mRNA as a template.
• Lysosomes break down waste products within the cell.
• Lysosomes contain digestive enzymes that break down waste products.
• Chloroplasts produce food by photosynthesis in plants.
• Vacuoles store water, nutrients, or wastes within plant cells.
• Lysosomes break down food particles and worn-out parts of the cell.
• Golgi apparatus modifies and packages proteins and lipids.
• Cytoskeleton provides structure to the cell and helps with movement.
• Plasma membrane regulates what enters and exits the cell.
• Golgi apparatus modifies and packages proteins for transport to other parts of the cell.
• Chloroplasts convert light into chemical energy during photosynthesis.
• Mitochondria produce energy through aerobic respiration.
• Nucleus contains genetic material (DNA) that controls cell activities.
• Ribosomes synthesize proteins using instructions from DNA.
• Centrosome organizes microtubules during mitosis.
• Ribosomes are responsible for protein synthesis.
• The cytoplasm contains organelles such as ribosomes, mitochondria, lysosomes, chloroplasts, vacuoles, and cytoskeleton.
• The nucleus is the control center of the cell where DNA is stored.
• Mitochondria are responsible for producing energy through respiration.
• Endoplasmic reticulum is involved in protein production and transport.
• Mitochondria produce ATP through aerobic respiration.
• Lysosomes contain digestive enzymes that break down waste materials within cells.