Cell Structure and Organelles

Cell Structure

• Plasma membrane: a thin layer of lipid and protein molecules that surrounds the cell
• Cytoplasm: a jelly-like substance inside the cell membrane where metabolic processes take place
• Nucleus: the control center of the cell where DNA is stored
• Mitochondria: organelles responsible for generating energy for the cell through cellular respiration
• Endoplasmic reticulum (ER): a network of membranous tubules and cisternae involved in protein synthesis and transport
• Ribosomes: small organelles found throughout the cytoplasm where protein synthesis occurs
• Lysosomes: membrane-bound sacs containing digestive enzymes that break down and recycle cellular waste
• Golgi apparatus: a complex of flattened sacs and tubes involved in protein modification and secretion

Cell Functions

• Metabolism: the process of energy conversion and molecular transformation within the cell
• Protein synthesis: the process of building proteins from amino acids
• Cell signaling: the process of sending and receiving signals between cells
• Cell division: the process of cell growth and reproduction
• Cell death: the process of programmed cell death (apoptosis) or unprogrammed cell death (necrosis)

Cell Transport

• Passive transport: movement of molecules from high to low concentration without energy input (diffusion, osmosis, facilitated diffusion)
• Active transport: movement of molecules from low to high concentration with energy input (carrier proteins, pumps)

Cell Cycle

• Interphase: the longest stage of the cell cycle where growth, replication, and preparation for cell division occur
• Mitosis: the stage of cell division where the replicated DNA is separated into two identical daughter cells
• Cytokinesis: the stage of cell division where the cytoplasm divides and the cell splits into two daughter cells

Cell Specialization

• Differentiation: the process of cells becoming specialized for specific functions
• Stem cells: undifferentiated cells capable of differentiating into various cell types
• Cellular differentiation: the process of cells becoming specialized for specific functions (e.g., nerve cells, muscle cells, epithelial cells)

Cell Structure

• The plasma membrane is a thin layer of lipid and protein molecules that surrounds the cell, regulating what enters and leaves.
• Cytoplasm is a jelly-like substance inside the cell membrane where metabolic processes, such as protein synthesis and cell signaling, take place.
• The nucleus is the control center of the cell where DNA is stored, and it regulates cell growth and division.
• Mitochondria are organelles responsible for generating energy for the cell through cellular respiration, producing ATP.
• The endoplasmic reticulum (ER) is a network of membranous tubules and cisternae involved in protein synthesis, transport, and lipid synthesis.
• Ribosomes are small organelles found throughout the cytoplasm where protein synthesis occurs, translating mRNA into amino acid sequences.
• Lysosomes are membrane-bound sacs containing digestive enzymes that break down and recycle cellular waste, maintaining cellular homeostasis.
• The Golgi apparatus is a complex of flattened sacs and tubes involved in protein modification, sorting, and secretion.

Cell Functions

• Metabolism involves the process of energy conversion and molecular transformation within the cell, including anabolic and catabolic reactions.
• Protein synthesis is the process of building proteins from amino acids, involving transcription and translation.
• Cell signaling is the process of sending and receiving signals between cells, allowing for communication and coordination.
• Cell division is the process of cell growth and reproduction, involving the cell cycle and mitosis.
• Cell death can occur through programmed cell death (apoptosis) or unprogrammed cell death (necrosis), both playing crucial roles in development and disease.

Cell Transport

• Passive transport is the movement of molecules from high to low concentration without energy input, including diffusion, osmosis, and facilitated diffusion.
• Active transport is the movement of molecules from low to high concentration with energy input, using carrier proteins and pumps.

Cell Cycle

• Interphase is the longest stage of the cell cycle where growth, replication, and preparation for cell division occur, involving G1, S, and G2 phases.
• Mitosis is the stage of cell division where the replicated DNA is separated into two identical daughter cells, involving prophase, metaphase, anaphase, and telophase.
• Cytokinesis is the stage of cell division where the cytoplasm divides and the cell splits into two daughter cells, resulting in two identical cells.

Cell Specialization

• Differentiation is the process of cells becoming specialized for specific functions, involving the expression of specific genes and proteins.
• Stem cells are undifferentiated cells capable of differentiating into various cell types, playing a crucial role in development and tissue repair.
• Cellular differentiation is the process of cells becoming specialized for specific functions, such as nerve cells, muscle cells, and epithelial cells, each with unique structures and functions.