Cell Biology: Structure and Functions

Cell Structure

• Plasma membrane: semi-permeable, regulates what enters and leaves the cell
• Cytoplasm: jelly-like substance inside cell membrane, site of metabolic reactions
• Nucleus: contains DNA, controls cell growth and reproduction
• Mitochondria: generates energy for cell through cellular respiration
• Endoplasmic reticulum (ER): transports and modifies proteins, lipids
• Ribosomes: site of protein synthesis
• Lysosomes: contains digestive enzymes, breaks down and recycles cellular waste
• Golgi apparatus: modifies, packages, and transports proteins and lipids

Cell Membrane Structure and Function

• Phospholipid bilayer: arrangement of phospholipid molecules with hydrophilic heads and hydrophobic tails
• Selective permeability: allows certain substances to pass through while keeping others out
• Passive transport: movement of molecules from high to low concentration (diffusion, osmosis)
• Active transport: movement of molecules from low to high concentration using energy

Cellular Organelles and Their Functions

• Chloroplasts: site of photosynthesis, converts light energy into chemical energy
• Cilia and flagella: structures involved in movement and sensing the environment
• Peroxisomes: contains enzymes that break down fatty acids and amino acids
• Centrioles: involved in formation of cilia, flagella, and spindle fibers
• Vacuoles: stores water, salts, and nutrients, helps maintain cellular turgor pressure

Cell Division

• Mitosis: process of cell division resulting in two daughter cells genetically identical to parent cell
  • Interphase: cell grows, replicates DNA, and prepares for cell division
  • Prophase: chromatin condenses, nuclear envelope breaks down
  • Metaphase: chromosomes line up at center of cell
  • Anaphase: sister chromatids separate
  • Telophase: nuclear envelope reforms, chromatin uncoils
• Meiosis: process of cell division resulting in four non-identical daughter cells with half the number of chromosomes as parent cell
  • Important for gamete formation and genetic variation

Cell Structure

• Plasma membrane is semi-permeable, regulating what enters and leaves the cell
• Cytoplasm is a jelly-like substance inside the cell membrane, where metabolic reactions take place
• The nucleus contains DNA and controls cell growth and reproduction
• Mitochondria generate energy for the cell through cellular respiration
• Endoplasmic reticulum (ER) transports and modifies proteins and lipids
• Ribosomes are the site of protein synthesis
• Lysosomes contain digestive enzymes, breaking down and recycling cellular waste
• Golgi apparatus modifies, packages, and transports proteins and lipids

Cell Membrane Structure and Function

• Phospholipid bilayer is an arrangement of phospholipid molecules with hydrophilic heads and hydrophobic tails
• The cell membrane has selective permeability, allowing certain substances to pass through while keeping others out
• Passive transport occurs through diffusion and osmosis, moving molecules from high to low concentration
• Active transport moves molecules from low to high concentration using energy

Cellular Organelles and Their Functions

• Chloroplasts are the site of photosynthesis, converting light energy into chemical energy
• Cilia and flagella are structures involved in movement and sensing the environment
• Peroxisomes contain enzymes that break down fatty acids and amino acids
• Centrioles are involved in the formation of cilia, flagella, and spindle fibers
• Vacuoles store water, salts, and nutrients, helping maintain cellular turgor pressure

Cell Division

• Mitosis is the process of cell division resulting in two daughter cells genetically identical to the parent cell
• Mitosis consists of:
  • Interphase: cell growth, DNA replication, and preparation for cell division
  • Prophase: chromatin condenses, and the nuclear envelope breaks down
  • Metaphase: chromosomes line up at the center of the cell
  • Anaphase: sister chromatids separate
  • Telophase: nuclear envelope reforms, and chromatin uncoils
• Meiosis is the process of cell division resulting in four non-identical daughter cells with half the number of chromosomes as the parent cell
• Meiosis is important for gamete formation and genetic variation

Learn about the different components of a cell, their functions and roles in maintaining cellular processes. From the plasma membrane to lysosomes, this quiz covers the essential structures of a cell.