Cell Structure of Archaea and Bacteria

Domains of Life

Archaea Cell Structure

• Cell wall: Pseudopeptidoglycan (peptidoglycan without D-amino acids) or S-layer (protein layer)
• Cell membrane: Ether lipids (instead of ester lipids found in Bacteria and Eukarya)
• Flagella: Archaeal flagella are composed of archaeal flagellin proteins
• Genetic material: Circular chromosome and multiple small circular plasmids

Bacteria Cell Membrane

• Phospholipid bilayer: Composed of ester lipids
• Fluid mosaic model: Proteins and lipids are embedded in the membrane
• Semipermeable: Allows certain substances to pass through
• Functions: Regulates what enters and leaves the cell, involved in cell signaling and metabolism

Eukaryotic Cell Organelles

• Nucleus: Contains genetic material, surrounded by a double membrane
• Mitochondria: Site of cellular respiration, generates energy for the cell
• Endoplasmic reticulum (ER): Involved in protein synthesis, transportation, and lipid synthesis
• Golgi apparatus: Modifies and packages proteins and lipids for transport
• Lysosomes: Contains digestive enzymes, involved in cellular digestion and recycling
• Ribosomes: Site of protein synthesis

Plant Cell Walls

• Cellulose: Main component, provides structural support and rigidity
• Hemicellulose: Cross-links cellulose fibers, adds strength and flexibility
• Pectin: Found in the middle lamella, helps hold cells together
• Lignin: Found in woody plants, adds strength and rigidity
• Functions: Provides support, protection, and maintenance of cell shape

Animal Tissue Types

• Epithelial tissue: Forms the lining of organs and glands, protects and absorbs
• Connective tissue: Provides support and structure, connects organs and tissues
• Muscle tissue: Enables movement and contraction
• Nervous tissue: Transmits and processes information
• Functions: Each tissue type has specific functions that contribute to the overall functioning of the organism

Domains of Life

Archaea Cell Structure

• Unique cell wall: Composed of pseudopeptidoglycan (lacking D-amino acids) or a protein layer (S-layer)
• Ether lipids in membrane: Instead of ester lipids found in Bacteria and Eukarya
• Archaeal flagella: Composed of archaeal flagellin proteins
• Genetic material: Circular chromosome and multiple small circular plasmids

Bacteria Cell Membrane

• Phospholipid bilayer: Composed of ester lipids, differing from Archaea
• Fluid mosaic model: Proteins and lipids embedded in the membrane, allowing selective permeability
• Semipermeable membrane: Regulates what enters and leaves the cell
• Cell signaling and metabolism: Involved in these processes

Eukaryotic Cell Organelles

• Nucleus: Contains genetic material, surrounded by a double membrane
• Mitochondria: Site of cellular respiration, generating energy for the cell
• Endoplasmic reticulum (ER): Involved in protein synthesis, transportation, and lipid synthesis
• Golgi apparatus: Modifies and packages proteins and lipids for transport
• Lysosomes: Contains digestive enzymes, involved in cellular digestion and recycling
• Ribosomes: Site of protein synthesis

Plant Cell Walls

• Cellulose: Main component, providing structural support and rigidity
• Hemicellulose: Cross-links cellulose fibers, adding strength and flexibility
• Pectin: Found in the middle lamella, holding cells together
• Lignin: Found in woody plants, adding strength and rigidity
• Cell wall functions: Provides support, protection, and maintenance of cell shape

Animal Tissue Types

• Epithelial tissue: Forms the lining of organs and glands, protecting and absorbing
• Connective tissue: Provides support and structure, connecting organs and tissues
• Muscle tissue: Enables movement and contraction
• Nervous tissue: Transmits and processes information
• Tissue functions: Each type has specific functions contributing to the overall functioning of the organism