Cell Structure and Function: Prokaryotes and Eukaryotes

Page 1

• Overview of cell structure and function

• Focus on prokaryotic and eukaryotic cells

Page 2: Cell Theory

• Key Principles:

  • The cell is the smallest unit of life.

  • All living things are composed of cells.

  • All cells arise from pre-existing cells.

Page 3: All Cells Contain

• Essential Components:

  • Plasma Membrane: separates living cell from non-living environment.

  • Cytoplasm: jelly-like substance within the cell.

  • Ribosomes: sites of protein synthesis.

  • DNA: genetic material.

Page 4: Main Types of Cells

• Prokaryotic Cells:

  • Lack a membrane-bound nucleus.

• Eukaryotic Cells:

  • Have a true nucleus.

Page 5: Structure of a Prokaryotic Cell

• DNA Location:

  • Found in the nucleoid region.

• DNA Characteristics:

  • One large circular piece, "naked" with few proteins.

Page 6: Prokaryotic Cell Features

• Organelles:

  • No membrane-bound organelles or complex internal membranes.

• Ribosomes:

  • Small 60S ribosomes.

• Cell Wall:

  • Most prokaryotes have a cell wall.

Page 7: Reproduction in Prokaryotic Cells

• Reproduction Method:

  • Asexual reproduction by fission.

• Genetic Recombination:

  • Rare occurrence.

Page 8: Kingdom Monera

• Domains:

  • Domain Bacteria: Eubacteria and Cyanobacteria (photosynthetic).

  • Domain Archae: Archaebacteria (e.g., halophiles, thermophiles).

Page 9: Structure of a Eukaryotic Cell

• Nucleus:

  • Contains a true nucleus with double membrane.

• DNA:

  • Linear DNA organized in chromosomes.

Page 10: Eukaryotic Cell Features

• Organelles:

  • Contains many membrane-bound organelles.

• Ribosomes:

  • Large 80S ribosomes.

Page 11: Eukaryotic Reproduction

• Fission/Asexual Reproduction:

  • Little to no genetic recombination.

• Sexual Reproduction:

  • Significant genetic recombination.

Page 12: Domain Eukarya

• Kingdoms:

  • Protista, Fungi, Plantae, Animalia.

Page 13: Organelles Overview

• Introduction to various organelles in cells.

Page 14-15: Organelles in Animal and Plant Cells

• Animal Cell Organelles:

  • Nucleus, nuclear membrane, nuclear pore.

• Plant Cell Organelles:

  • Similar structures with additional components.

Page 16: Plasma Membrane

• Structure:

  • Phospholipid bilayer with embedded proteins.

• Function:

  • Regulates entry and exit of substances.

Page 17: Organelles with Double Membranes

• Examples:

  • Nucleus, mitochondrion, chloroplast.

Page 18: Nucleus

• Structure:

  • Double membrane, nuclear pore, nucleolus.

• Function:

  • Stores DNA, DNA replication, RNA synthesis.

Page 19-20: Mitochondrion

• Function:

  • Cellular respiration and ATP production.

• Structure:

  • Cristae (folded inner membrane) and matrix.

Page 21-23: Mitochondrion and Chloroplast

• Semiautonomous Organelles:

  • Contain circular DNA and 60S ribosomes.

Page 24-26: Endosymbiont Theory

• Concept:

  • Mitochondria and chloroplasts originated from engulfed bacteria.

• Evidence:

  • Similar sizes, circular DNA, prokaryotic ribosomes.

Page 27-28: Evolution of Organelles

• Mitochondria:

  • Originated from purple nonsulfur bacteria.

• Chloroplasts:

  • Originated from cyanobacteria.

Page 30-31: Organelles with Single Membranes

• Examples:

  • Vacuoles, peroxisomes, lysosomes.

Page 32: Lysosome

• Function:

  • Breaks down macromolecules using digestive enzymes.

Page 33: Ribosomes

• Structure:

  • Composed of rRNA and protein, no membrane.

• Function:

  • Protein synthesis.

Page 34-40: Endomembrane System

• Components:

  • Smooth and rough endoplasmic reticulum, Golgi apparatus, vesicles.

Page 41-44: Golgi Apparatus

• Function:

  • Modifies, sorts, and packages proteins for transport.

Page 45-49: Protein Transport

• Process:

  • Proteins synthesized in RER are sent to Golgi for modification and sorting.

Page 50-51: Cytoskeleton

• Components:

  • Actin microfilaments, intermediate filaments, microtubules.

• Function:

  • Provides structure and facilitates intracellular transport.

Page 52-55: Cytoskeleton Components

• Actin Microfilaments:

  • Involved in cell shape and movement.

• Intermediate Filaments:

  • Provide structural support.

• Microtubules:

  • Involved in intracellular movement and cell motility.

Page 58-60: Cilia and Flagella

• Structure:

  • Composed of microtubules, used for movement.

Page 61-62: Cell Wall and Extracellular Matrix

• Cell Wall:

  • Provides structure, found in plants, fungi, and bacteria.

• Extracellular Matrix:

  • Composed of proteins and carbohydrates, found in animal cells.

Page 66-70: Comparison of Plant and Animal Cells

• Similarities:

  • Both are eukaryotic.

• Differences:

  • Plant cells have cell walls, chloroplasts, and large central vacuoles.

Page 71: Review

• Summary of prokaryotic and eukaryotic cell structures and organelles.