Prokaryotic and Eukaryotic Cells Structure and Function In general microbes or microorganisms may be either prokaryotic (bacteria) or eukaryotic (protists, fungi, and some animals). However, there are some microbial organisms that appear to be intermediates between prokaryotes and eukaryotes (they possess a nucleus but do not have mitochondria or chloroplasts, an example is Giardia intestinalis. Prokaryotes differ from eukaryotes in several ways including but not limited to: Characteristics Prokaryotic Eukaryotic Types bacteria (monerans) protists, fungi, plants, and animals Organization unicellular usually multicellular (exception some protists) Cell size small (0.1-10um) larger (10-100um) Membrane-bound organelles absent present Reproduction asexual asexual and sexual DNA circular linear Proteins assoc. with DNA Basic Histone Plasma membrane No sterols Sterols Ribosomes 70S 80S Cytoskeleton Absent present PROKARYOTIC CELLS [...]... are dormant structures produced by some species of Bacillus and Clostridium Shapes and arrangements of bacteria There are six common shapes of bacteria: coccus, bacillus, coccobacillus, vibrio, spirochete, and spirullum and there are several arrangements of these cells: single, chains (strepto-), clusters (staphylo-), pairs (diplo-) etc Eukaryotic Cell Cell Membrane Cell membrane Structure Components... and synthetic processes The following are found within the protoplasm of the prokaryotic cell: chromatin body or the bacterial chromosome nucleoid or nuclear region of the cell that is associated with the chromatin body plasmids are tiny circular extrachromosomal strands of DNA ribosomes are small structures consisting of RNA and proteins that are involved in protein synthesis inclusions or granules... and active transport) Recognition (e.g., self vs non-self) Reception (for protein hormones) Adhesion Nucleus Structure and Function – membrane similar to cell membrane (similar function) – Nucleolus (formation of ribosomes) – Chromosomes (gene expression) – Nucleoplasm (matrix) Ribosomes • Structure – rRNA – Proteins • Function – Site of protein formation (translation) • Found in both prokaryotes and. .. primary dye) and Gram - bacteria stain pink (the color of the counterstain or second dye) The Gram stain is a differential staining technique because different species of bacteria stain differently The difference is a result of the composition of the cell wall The protoplasm or cytoplasm is the dense gelatinous solution within the cell membrane that is the primary site for the cell’s biochemical and synthetic... layer (outermost layer) differs greatly in thickness, organization and chemical composition depending on the bacterial species T Beneath the outer layer lies the cell wall The cell membrane is a thin flexible sheet that surrounds the contents of the bacterial cell Its functions include: transport, energy extraction, nutrient processing, and synthesis The Gram Stain An important tool in the identification... structurally) Endoplasmic Reticulum • Structure membranous system of tunnels and sacs – Rough – with ribosomes on surface – Smooth- no ribosomes on surface • Function – Rough – protein synthesis – Smooth- lipid synthesis Golgi Apparatus • Structure also membranous, kind of like a stack of pancakes • Function processing of lipids and proteins Lysosomes • Structure membrane bound sac containing hydrolytic... Energy transfer by ATP synthesis Chloroplast • Structure – Also cigar or spindle shaped, double membrane-bound, green • Function – Site of photosynthesis OTHER STUCTURES • • • • Cell walls, not in animal cells Vacoules Cytoskeleton Cytoplasm