Procaryote Cell Structure and Function

I.  Procaryote Cell Structure

II. Procaryote Anatomy

    A. Internal Structures

        1. Plasma membrane

                Functions of plasma membrane

                    a)  semi-permeable

                    b)  active transport

                    c)  metabolic activity
 

        2. Mesosomes
 

        3. Cytoplasmic matrix

           a)  inclusion bodies (granules)
 

           b)  ribosomes
 

        4. Nucleoid

              nuclear region

              single circular DNA molecule
 

        5. Plasmids

             extrachromosomal circular DNA
 

    B. Cell Wall

         1. Gram-positive

             peptidogylcan (murein)

             teichoic acid

             small periplasmic space

         2. Gram-negative

             outer membrane (envelope)

             thin peptidogylcan layer

             Braun's protein

             porin proteins

             lipopolysaccharide (LPS)
 

    C. External Structures

          1. Capsules

                 mucoid outer layers

                 generally polysaccharide

               a) capsules:  well organized, not easily removed from cell
 

               b) slime layers:  diffuse, unorganized
 

               c) glycolyx:  network of polysaccharide extending from cell surface
 

               d) S- layers:  patterned layer of protein or glycoprotein
 

        2. Pili/fimbriae

               a) attachment

               b) sex pili

               c) bacteriophage
 

        3. Flagella

             long, thread-like protein appendages

            a) orientation

                  monotrichous, peritrichous, amphitrichous, lophotrichous
 

            b) ultrastructure

                1) filament

                2) basal body

                3) hook

            c) chemotaxis

    D. Bacterial Endospores

Last updated June 11, 2007.