Cell Structure

Cell Biology

Cell Structure

• Plasma membrane: semi-permeable membrane that separates the cell from its environment
• Cytoplasm: jelly-like substance inside the cell where metabolic processes occur
• Nucleus: contains DNA, the genetic material of the cell
• Mitochondria: responsible for generating energy for the cell through cellular respiration
• Endoplasmic reticulum (ER): involved in protein synthesis and transport
• Ribosomes: responsible for protein synthesis
• Lysosomes: contain digestive enzymes that break down and recycle cellular waste
• Golgi apparatus: involved in protein modification and transport

Cellular Processes

• Cell division: process by which a cell becomes two daughter cells
  • Mitosis: process of cell division that results in two identical daughter cells
  • Meiosis: process of cell division that results in four non-identical daughter cells (gametes)
• Cell signaling: process by which cells communicate with each other
  • Receptors: proteins that bind to signaling molecules
  • Signaling pathways: series of molecular interactions that transmit signals
• Cellular transport: movement of molecules into and out of the cell
  • Passive transport: diffusion, osmosis, and facilitated diffusion
  • Active transport: energy-dependent transport of molecules

Cell Types

• Prokaryotic cells: lack a true nucleus and are typically small and simple
  • Bacteria: examples of prokaryotic cells
• Eukaryotic cells: have a true nucleus and are typically larger and more complex
  • Animal cells: examples of eukaryotic cells
  • Plant cells: examples of eukaryotic cells with cell walls and chloroplasts

Cell Cycle

• Interphase: stage of the cell cycle where the cell grows and prepares for cell division
• Mitotic phase: stage of the cell cycle where cell division occurs
• G1 phase: stage of interphase where the cell grows and prepares for DNA replication
• S phase: stage of interphase where DNA replication occurs
• G2 phase: stage of interphase where the cell prepares for cell division

Cell Biology

Cell Structure

• Plasma membrane: a semi-permeable membrane that separates the cell from its environment and regulates what enters and leaves the cell.
• Cytoplasm: a jelly-like substance inside the cell where metabolic processes such as glycolysis, protein synthesis, and cell signaling occur.
• Nucleus: a membrane-bound organelle that contains DNA, the genetic material of the cell, and is responsible for controlling cell growth and reproduction.
• Mitochondria: organelles responsible for generating energy for the cell through cellular respiration, converting glucose into ATP.
• Endoplasmic reticulum (ER): a network of membranous tubules and cisternae involved in protein synthesis, transport, and storage.
• Ribosomes: small organelles found throughout the cytoplasm, responsible for protein synthesis by translating messenger RNA into amino acid sequences.
• Lysosomes: membrane-bound organelles that contain digestive enzymes and break down and recycle cellular waste and foreign substances.
• Golgi apparatus: a complex of flattened sacs and tubules that modify and transport proteins and lipids synthesized by the ER.

Cellular Processes

• Cell division: the process by which a cell becomes two daughter cells, essential for growth, development, and reproduction.
• Mitosis: a type of cell division that results in two identical daughter cells, characteristic of somatic cells.
• Meiosis: a type of cell division that results in four non-identical daughter cells, characteristic of gametes.
• Cell signaling: the process by which cells communicate with each other through signaling molecules, such as hormones and neurotransmitters.
• Cellular transport: the movement of molecules into and out of the cell, including passive transport (diffusion, osmosis, and facilitated diffusion) and active transport.

Cell Types

• Prokaryotic cells: lack a true nucleus and are typically small and simple, with a single circular chromosome.
• Bacteria: examples of prokaryotic cells, such as E. coli and Staphylococcus aureus.
• Eukaryotic cells: have a true nucleus and are typically larger and more complex, with linear chromosomes.
• Animal cells: examples of eukaryotic cells, lacking cell walls and chloroplasts.
• Plant cells: examples of eukaryotic cells, with cell walls and chloroplasts, responsible for photosynthesis.

Cell Cycle

• Interphase: the stage of the cell cycle where the cell grows and prepares for cell division, including DNA replication.
• Mitotic phase: the stage of the cell cycle where cell division occurs, including mitosis and cytokinesis.
• G1 phase: the stage of interphase where the cell grows and prepares for DNA replication, characterized by cell growth and protein synthesis.
• S phase: the stage of interphase where DNA replication occurs, resulting in two identical copies of the DNA.
• G2 phase: the stage of interphase where the cell prepares for cell division, characterized by organelle duplication and preparation for mitosis.