Cell Signaling: Cellular Communication

Cellular Processes

Cell Signaling

• The process by which cells communicate with each other and respond to their environment
• Involves signal transduction pathways, which allow cells to respond to stimuli
• Types of cell signaling:
  • Autocrine signaling: signals that affect the same cell that produced them
  • Paracrine signaling: signals that affect nearby cells
  • Endocrine signaling: signals that affect cells distant from the signaling cell
  • Direct signaling: signals that directly affect adjacent cells

Cellular Transport

• The movement of molecules into, out of, and within cells
• Types of cellular transport:
  • Passive transport: movement of molecules down their concentration gradient
    • Diffusion: random movement of molecules from high to low concentration
    • Osmosis: movement of water molecules from high to low concentration
  • Active transport: movement of molecules against their concentration gradient
    • Requires energy input
    • Examples: pumps, carriers, and vesicle transport

Cell Division

• The process by which a cell divides into two daughter cells
• Types of cell division:
  • Mitosis: division of somatic cells, resulting in two genetically identical daughter cells
  • Meiosis: division of gametes (sperm or egg cells), resulting in four genetically unique daughter cells

Photosynthesis

• The process by which cells convert light energy into chemical energy
• Occurs in chloroplasts of plant cells and some algae
• Equation: 6 CO2 + 6 H2O + light energy → C6H12O6 (glucose) + 6 O2

Cellular Respiration

• The process by which cells convert glucose into energy (ATP)
• Occurs in mitochondria of cells
• Equation: C6H12O6 (glucose) + 6 O2 → 6 CO2 + 6 H2O + ATP (energy)

Protein Synthesis

• The process by which cells create proteins
• Involves transcription of DNA to RNA, and translation of RNA to protein
• Steps:
  1. Transcription: DNA → RNA
  2. Translation: RNA → protein
  3. Post-translational modification: protein folding and modification

Cellular Processes

Cell Signaling

• Cell signaling involves signal transduction pathways, allowing cells to respond to stimuli
• Types of cell signaling:
  • Autocrine signaling: signals that affect the same cell that produced them
  • Paracrine signaling: signals that affect nearby cells
  • Endocrine signaling: signals that affect cells distant from the signaling cell
  • Direct signaling: signals that directly affect adjacent cells

Cellular Transport

• Cellular transport is the movement of molecules into, out of, and within cells
• Passive transport: movement of molecules down their concentration gradient
  • Diffusion: random movement of molecules from high to low concentration
  • Osmosis: movement of water molecules from high to low concentration
• Active transport: movement of molecules against their concentration gradient, requiring energy input
  • Examples: pumps, carriers, and vesicle transport

Cell Division

• Cell division is the process by which a cell divides into two daughter cells
• Types of cell division:
  • Mitosis: division of somatic cells, resulting in two genetically identical daughter cells
  • Meiosis: division of gametes (sperm or egg cells), resulting in four genetically unique daughter cells

Photosynthesis

• Photosynthesis converts light energy into chemical energy
• Occurs in chloroplasts of plant cells and some algae
• Equation: 6 CO2 + 6 H2O + light energy → C6H12O6 (glucose) + 6 O2

Cellular Respiration

• Cellular respiration converts glucose into energy (ATP)
• Occurs in mitochondria of cells
• Equation: C6H12O6 (glucose) + 6 O2 → 6 CO2 + 6 H2O + ATP (energy)

Protein Synthesis

• Protein synthesis involves transcription of DNA to RNA, and translation of RNA to protein
• Steps:
  • Transcription: DNA → RNA
  • Translation: RNA → protein
  • Post-translational modification: protein folding and modification