Cell Structure and Anatomy

• Cells are the basic structural and functional units of life
• Anatomy refers to the study of the structure and organization of living organisms
• Cell structure includes various components, each with specific functions

Cell Membrane

• Encloses the cell, separating its contents from the external environment
• Composed of a phospholipid bilayer with embedded proteins
• Regulates the passage of substances in and out of the cell (selective permeability)
• Involved in cell signaling and cell-to-cell interactions

Cytoplasm

• Gel-like substance within the cell membrane, excluding the nucleus
• Contains water, ions, enzymes, nutrients, and various organelles
• Site of many metabolic reactions

Nucleus

• Control center of the cell, containing the genetic material (DNA)
• Surrounded by a nuclear envelope, a double membrane structure with pores
• Houses the nucleolus, responsible for ribosome synthesis
• DNA is organized into chromosomes during cell division

Endoplasmic Reticulum (ER)

• Network of interconnected membranes extending throughout the cytoplasm
• Two types: Rough ER (RER) and Smooth ER (SER)
• RER has ribosomes attached and is involved in protein synthesis and modification
• SER lacks ribosomes and is involved in lipid synthesis, detoxification, and calcium storage

Ribosomes

• Site of protein synthesis
• Found freely floating in the cytoplasm or attached to the RER
• Composed of ribosomal RNA (rRNA) and proteins

Golgi Apparatus

• Stack of flattened membrane-bound sacs (cisternae)
• Modifies, sorts, and packages proteins and lipids synthesized in the ER
• Forms vesicles that transport molecules to other organelles or the cell membrane

Mitochondria

• Powerhouse of the cell, responsible for ATP production through cellular respiration
• Double-membraned organelle with an inner membrane folded into cristae
• Contains its own DNA and ribosomes

Lysosomes

• Membrane-bound organelles containing digestive enzymes
• Involved in intracellular digestion, breaking down cellular waste and debris
• Play a role in apoptosis (programmed cell death)

Peroxisomes

• Small, membrane-bound organelles involved in detoxification
• Contain enzymes that break down fatty acids and produce hydrogen peroxide (H2O2)
• Catalase enzyme converts H2O2 into water and oxygen

Cytoskeleton

• Network of protein fibers providing structural support and shape to the cell
• Three main types: microfilaments, intermediate filaments, and microtubules
• Involved in cell movement, cell division, and intracellular transport

Centrioles

• Cylindrical structures composed of microtubules
• Involved in cell division, specifically in the formation of the mitotic spindle

Cell Structures and Functions Summary

• Cell Membrane: Encloses the cell, regulates transport, and facilitates cell interactions
• Cytoplasm: Gel-like matrix containing organelles and facilitating metabolic reactions
• Nucleus: Contains DNA and controls cell activities
• Endoplasmic Reticulum: Involved in protein and lipid synthesis
• Ribosomes: Site of protein synthesis
• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids
• Mitochondria: Generates ATP through cellular respiration
• Lysosomes: Intracellular digestion and waste removal
• Peroxisomes: Detoxification and breakdown of fatty acids
• Cytoskeleton: Provides structural support and facilitates cell movement
• Centrioles: Involved in cell division

Cells are fundamental units of life, with each component having specialized functions. Key components include the cell membrane, cytoplasm and nucleus. The cell membrane regulates substance passage, the cytoplasm hosts metabolic reactions, and the nucleus controls the cell.