BACTERIAL MORPHOLOGY CON’T Plasma (cytoplasmic) membrane

Phospholipid bilayer (Self- assembly) Two fatty acid tails (hydrophobic) Glycerol-Phosphate head (hydrophilic)

Fatty acids (hydrophobic) Glycerol and phosphate (hydrophilic)

Phospholipid arrangement in water

Phospholipid self- arrangement

Proteins Integral proteins Integral proteins –Transport Peripheral proteins Peripheral proteins –Enzymes

Integral protein Peripheral protein

Plasma membrane functions (BET) Barrier Barrier Energy production Energy production Transport Transport

Plasma membrane Target for chemotherapy and disinfection Target for chemotherapy and disinfection – Damage to the membrane by alcohols, quaternary ammonium (detergents) and polymyxin antibiotics causes leakage of cell contents. Disruption of phospholipids Disruption of phospholipids Selective permeability allows passage of some molecules Selective permeability allows passage of some molecules Enzymes for ATP production Enzymes for ATP production Photosynthetic pigments on foldings called chromatophores or thylakoids Photosynthetic pigments on foldings called chromatophores or thylakoids

Transport across membranes Simple diffusion: Movement of a solute from an area of high concentration to an area of low concentration (often known as passive transport) Simple diffusion: Movement of a solute from an area of high concentration to an area of low concentration (often known as passive transport) Facilitative diffusion: Solute combines with a transporter protein in the membrane Facilitative diffusion: Solute combines with a transporter protein in the membrane

Transport across membranes Active (requires energy, usually from lower to higher concentration) Active (requires energy, usually from lower to higher concentration)

Passive transport across membranes Simple diffusion Simple diffusion Facilitated diffusion (permeases) Facilitated diffusion (permeases) Osmosis Osmosis

Higher concentration Lower concentration Facilitated diffusion No energy used !!

Osmosis Sugar or salt molecules (solute) Semi-permeable membrane (only water flows) Liquids flow towards higher solute Liquids flow towards higher solute concentration (lower liquid concentration)

Active transport across membranes Group translocation Group translocation – Substance is altered during transport (metabolism-glucose-6-PO 3 ) sugars are phosphorylated Carrier proteins Carrier proteins – Similar to facilitated diffusion, but needs energy Group translocation of substances requires a transporter protein and PEP (phosphoenolpyruvate) Group translocation of substances requires a transporter protein and PEP (phosphoenolpyruvate) Active transport of substances requires a transporter protein and ATP Active transport of substances requires a transporter protein and ATP

Energy is used! Higher concentration Lower concentration Group translocation Glucose Phosphate

phosphoenolpyruvate

Microbial Nutrition Acquisition

Cytoplasm contents –Water, proteins, carbohydrates, lipids, inorganic ions, DNA, RNA and inclusions

Nuclear area No nuclear membrane No nuclear membrane Chromosome Chromosome Plasmid Plasmid

Bacterial chromosome One only double stranded (ds) DNA Attached to plasma membrane

Bacterial plasmid Extrachromosomal genetic material Replicate independently Not crucial for survival (resistance, enzymes, etc)

Ribosomes Protein synthesis Protein synthesis Two subunits 30 and 50 S = 70 S (rRNA) Two subunits 30 and 50 S = 70 S (rRNA) Target for antibiotic action Target for antibiotic action

Inclusions Reserve deposits Reserve deposits – lipids, sulfur, carboxysomes – Metachromatic granules – Polysaccharide granules – Gas

Inclusions

Endospores –Only Gram-positives Bacillus spp. Bacillus spp. Clostridium spp. Clostridium spp. –Highly resistant –Spore coat has a form of dipicolinic acid and Ca + ions in it

Spores

The eucaryotic cell Algae Algae Protozoa Protozoa Plants Plants Animals Animals

The eucaryotic cell (cont.) Larger and more complex than procaryotes Larger and more complex than procaryotes 10 to 100  m 10 to 100  m Membrane-bounded organelles Membrane-bounded organelles

Flagella and Cilia Locomotion Locomotion Flagella, few and long Flagella, few and long Cilia, numerous and short Cilia, numerous and short

Movement of eukaryotic flagella and cilia Respiratory system Respiratory system Digestive system Digestive system Locomotion Locomotion

Cell wall of eucaryotes Not present in all eucaryotes (alga, plants, some fungi) Not present in all eucaryotes (alga, plants, some fungi) No peptidoglycan No peptidoglycan Simpler than procaryotes Simpler than procaryotes

Cell wall of eucaryotes (cont.) Cellulose Cellulose – Glucose polymer Chitin (most fungi, some protozoans) Chitin (most fungi, some protozoans) – N-acetylglucosamine polymer

Cell wall of eucaryotes (cont.) Polysaccharides (yeast) Polysaccharides (yeast) –Glucan –Mannan

Glycocalyx functions Strengthens the cell surface Strengthens the cell surface Helps attach cells together Helps attach cells together Cell to cell recognition Cell to cell recognition Sticky carbohydrates Sticky carbohydrates

Eucaryotes plasma (cytoplasmic) membrane Similar to procaryotes Similar to procaryotes –Receptor sites (carbohydrates) cell to cell recognition

Eucaryotes plasma (cytoplasmic) membrane (cont.) –Attachment sites for bacteria –Sterols (rigidity) –transport (passive and active)

Eucaryotes passive transport Diffusion Diffusion Facilitated diffusion Facilitated diffusion Osmosis Osmosis

Eucaryotes active transport (endocytosis) Phagocytosis (macrophages – cells are “eating”) Phagocytosis (macrophages – cells are “eating”) Pinocytosis (extracellular fluid into the cell—cells are “drinking”) Pinocytosis (extracellular fluid into the cell—cells are “drinking”)

Cytoplasm Cytoskeleton Cytoskeleton –Microfilaments –Intermediate filaments –Microtubules

Cytoplasm (cont.) Cytoskeleton functions Cytoskeleton functions –Shape –Movement Entire cell Entire cell Substances within the cell Substances within the cell

Nucleus Spherical to ovalSpherical to oval Contains DNAContains DNA combined with histonescombined with histones and nonhistonesand nonhistones

Nucleus (cont.) Chromatin (threadlike) Chromatin (threadlike) –Non-reproducing cells Chromosomes (rodlike structure) Chromosomes (rodlike structure) –Reproducing cells

Endoplasmic reticulum (ER) Network of sacs Network of sacs Synthesis and storage of lipids and proteins Synthesis and storage of lipids and proteins

Endoplasmic reticulum (ER) (cont.) Rough ER Rough ER – numerous ribosomes, protein synthesis Smooth ER Smooth ER – Lipid synthesis

Golgi Complex Similar to ER Similar to ER Receives ER products Receives ER products –Sorts –packages –delivers (secretory vesicles)

Mitochondria Double membrane Double membrane –Multy-folded inner membrane

Mitochondria (cont.) Provides a large surface for proteins involved in cellular respiration (ATP synthesis) Provides a large surface for proteins involved in cellular respiration (ATP synthesis) Multiply on their own Multiply on their own

Chloroplast Algae and green plants Algae and green plants Chlorophyll Chlorophyll Photosynthesis enzymes Photosynthesis enzymes Multiply on their own Multiply on their own

Lysosomes Derived from Golgi complex Derived from Golgi complex Free spheres in cytoplasm Free spheres in cytoplasm Contain powerful digestive enzymes Contain powerful digestive enzymes Numerous in white blood cells Numerous in white blood cells

Vacuoles Storage of nutrients Storage of nutrients Metabolic wastes Metabolic wastes Water Water