Lecturer: Pn Aslizah Bt Mohd Aris 06-4832168 / 016-7377621 Diploma in Microbiology MIC102 CHAPTER 1 Cell Theory- Structure and Function (PROKARYOTE) Lecturer: Pn Aslizah Bt Mohd Aris 06-4832168 / 016-7377621

What is Cell Biology? is an academic discipline which studies the physiological properties of cells, as well as their behaviours, interactions, and environment this is done both on a microscopic and molecular level. researches both single-celled organisms like bacteria and specialized cells in multicellular organisms like humans. 2

SYLLABUS CONTENT Cell Theory- Structure and Function Chap 1 Cell Theory- Structure and Function - Prokaryotic cell - Eukaryotic cell- Cell membrane Chap 2 Movement In And Out Of Cell - Diffusion, Osmosis, Active Transport, Endocytosis, Phagocytosis, Pinocytosis, Excocytosis Chap 3 Reproduction of Prokaryotic cell- -Binary fission and conjugation Chap 4 Reproduction of eukaryotic cell / Cell division - Chromosome morphology and function, The cell cycle and mitosis, Meiosis and gametogenesis

Overview: The Fundamental Units of Life The cell is the simplest collection of matter that can live. All organisms are made of cell. Cell structure is correlated to cellular function. All cells are related by their descent from earlier cells. For the Discovery Video Cells, go to Animation and Video Files. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

How do cellular components cooperate to help the cell function? Figure 6.1 How do cellular components cooperate to help the cell function?

What is a Cell? Basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals. General characteristic of cells is their microscopic size. Typical size-Eukaryotic cell: 10-100 µm in diameter -Prokaryotic cell: 1-10 µm in diameter

Cell Theory 1665: Robert Hooke, 1st observed cells, naming the shapes as “cork cellulae” (Latin= “small rooms”). Anton van Leeuwenhoek, 1st observed live cells, which he termed as “tiny animalcules”. 1839: Theodor Schwann reported that all animal tissues also consist of individual cells. Thus was born “CELL THEORY”

Cell Theory: The Principle Three (3) principles involves: All organisms are composed of one or more cells, and the life processes of metabolism and heredity occur within these cells. Cells are the smallest living things, the basic units of organization of all organisms. Cell arises only by division of previously existing cell.

Basic Cellular Architectures: Prokaryotic cells; refer to the presence Eukaryotic cells. @ absence of the cell structures. DOMAIN KINGDOM Prokaryotic cells Archaea Bacteria Eukaryotic cells Plantae Fungi Animalia Protista

Prokaryotic Cells Bacteria and archaea are prokaryotes. The figure (right) reviews the structure of a typical prokaryotic cell. Bacterium (plural, bacteria): single-celled organism with no nucleus and little or no intracellular compartmentalization; a prokaryote. Eubacterium (plural, eubacteria): member of one of the two main groups of prokaryotes, the other being archaebacteria; includes most present-day bacteria and cyanobacteria. Cyanobacterium (plural, cyanobacteria): bacteria that have chlorophyll and can carry out photosynthesis; considered by the endosymbiont theory to be the progenitor of eukaryotic chloroplats. 10

The Structure of a Prokaryotic Cell

simplest organisms. small, consisting of cytoplasm surrounded by a plasma membrane and encased within a rigid cell wall, lack complex interior organization. nucleoid is visible as a dense central region segregated from the cytoplasm. do contain complex structures, like ribosome to carry out protein synthesis. cell membrane carries out some of the function s organelles perform in eukaryotic cells.

The Cell Wall Strength of the cell comes primarily from its rigid cell wall, protects the cell, maintain its shape & prevent excessive uptake and loss of water. Prevents osmotic lysis Made of peptidoglycan (in bacteria) Figure 4.6

Peptidoglycan Polymer of disaccharide: N-acetylglucosamine (NAG) N-acetylmuramic acid (NAM) Figure 4.12

Peptidoglycan in Gram-Positive Bacteria Linked by polypeptides Figure 4.13a

Gram-Positive Bacterial Cell Wall Figure 4.13b

Gram-Negative Bacterial Cell Wall Figure 4.13c

Gram-positive Cell Wall Gram-negative Cell Wall Thick peptidoglycan Teichoic acids Thin peptidoglycan Outer membrane Periplasmic space Figure 4.13b–c

The Plasma Membrane Figure 4.14a

The Plasma Membrane Phospholipid bilayer Peripheral proteins Integral proteins Transmembrane Proteins Figure 4.14b

The Plasma Membrane Selective permeability allows passage of some molecules Enzymes for ATP production Photosynthetic pigments on foldings called chromatophores or thylakoids

Cytoplasm The substance inside the plasma membrane Figure 4.6

The Nucleoid Bacterial chromosome Contains genetic information Figure 4.6

Ribosomes Sites of protein synthesis Figure 4.6

The Prokaryotic Ribosome Protein synthesis 70S 50S + 30S subunits Figure 4.19

Inclusions Phosphate reserves Metachromatic granules (volutin) Energy reserves Ribulose 1,5- diphosphate carboxylase for CO2 fixation Protein-covered cylinders Iron oxide (destroys H2O2) Metachromatic granules (volutin) Polysaccharide granules Lipid inclusions Sulfur granules Carboxysomes Gas vacuoles Magnetosomes

Other characteristics most have no membrane bounded organelles, which characterize the eukaryotes. lack of the elaborate cytoskeleton found in eukaryotes. The DNA, enzymes, and other cytoplasmic constituents have access to all parts of the cell. cell contain no membrane bounded organelles; whole prokaryotes operate as a single unit rxns, not compartmentalized as in eukaryotes. “one room cabin in which eating, sleeping and watching TV is all occur”.

External Structures to the Cell Wall Glycocalyx. Flagella Axial filaments Fimbriae and pili.

Glycocalyx Outside cell wall Slime layer: unorganized and loose Usually sticky Capsule: neatly organized Slime layer: unorganized and loose Extracellular polysaccharide allows cell to attach Capsules prevent phagocytosis Figure 24.12

The Structure of a Prokaryotic Flagellum outside cell wall made of chains of flagellin attached to a protein hook anchored to the wall and membrane by the basal body Figure 4.8b

Arrangements of Bacterial Flagella

Axial Filaments Also called endoflagella In spirochetes Anchored at one end of a cell Rotation causes cell to move Figure 4.10a

Fimbriae and Pili Fimbriae allow attachment Figure 4.11

Fimbriae and Pili may have hairlike growth (called pili) on the outside of the cell). Facilitate transfer of DNA from one cell to another Gliding motility Twitching motility

LETS WATCH MOVIE !!! Prokaryotic Cell Structure and Function

ACTIVITY example: In pair discuss the function of bacteria/prokaryote structure and try to produce 1 table consist of the function of each structure STRUCTURES FUNCTIONS Flagellum Movement… 2. Pilus

See u tomorrow..thank you….