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.

Learn about the different components of a cell, including the plasma membrane, cytoplasm, nucleus, mitochondria, and endoplasmic reticulum.