do not possess a true nucleus and membrane bound organelles (e.g., bacteria)

• those that possess a true nucleus and membrane bound organelles. • multicellular organisms • plants, animals, fungi, parasites, and algae.

• are acellular organisms that possess only DNA OR RNA • They are dependent on host cells for their replication and are considered as obligate intracellular parasites

PROKARYOTIC VS. EUKARYOTIC Genetic Material - Not enclosed within a membrane; not associated with histones; usually circular

PROKARYOTIC VS. EUKARYOTIC Genetic Material - Enclosed within a membrane; associated with histones; usually linear

PROKARYOTIC VS. EUKARYOTIC Size - Smaller (1-2 um by 1-4 µm or less)

PROKARYOTIC VS. EUKARYOTIC Size - Greater than 5 µm in diameter

PROKARYOTIC VS. EUKARYOTIC Cell Type - Mostly unicellular

PROKARYOTIC VS. EUKARYOTIC Cell Type - Mostly multicellular

PROKARYOTIC VS. EUKARYOTIC Nucleus - No true nucleus and nuclear membrane; called nucleoid

PROKARYOTIC VS. EUKARYOTIC Nucleus - With true nucleus enclosed by nuclear membrane

PROKARYOTIC VS. EUKARYOTIC Cell Wall - Simple

PROKARYOTIC VS. EUKARYOTIC Cell Wall - Complex

PROKARYOTIC VS. EUKARYOTIC Cell Division - Budding or binary fission

PROKARYOTIC VS. EUKARYOTIC Cell Division - Mitosis

PROKARYOTIC VS. EUKARYOTIC Sexual Reproduction - No meiosis; transfer of DNA only

PROKARYOTIC VS. EUKARYOTIC Sexual Reproduction - Mitosis

PROKARYOTIC VS. EUKARYOTIC Cytoskeleton - Absent

PROKARYOTIC VS. EUKARYOTIC Cytoskeleton - Present

PROKARYOTIC VS. EUKARYOTIC Mesosome - Functions as mitochondria and Golgi complex

PROKARYOTIC VS. EUKARYOTIC Mesosome - Absent

PROKARYOTIC VS. EUKARYOTIC Ribosomes - 705; located in cytoplasm

PROKARYOTIC VS. EUKARYOTIC Ribosomes - 80S; located in membranes such as in the endoplasmic reticulum 70S; found in organelles such as mitochondria or chloroplast

PROKARYOTIC VS. EUKARYOTIC Membrane-bound organelles - absent

PROKARYOTIC VS. EUKARYOTIC Membrane-bound organelles - present

PROKARYOTIC VS. EUKARYOTIC Extrachromosomal plasmid - Present

PROKARYOTIC VS. EUKARYOTIC Extrachromosomal plasmid - Absent

PROKARYOTIC VS. EUKARYOTIC Duration of cycle - short (20-60 minutes)

PROKARYOTIC VS. EUKARYOTIC Duration of cycle - Long (12-24 hours)

• acellular organisms • outer surface is called capsid, which is composed of • repeating sub units called CAPSOMERES • possess only a single nucleic acid, either DNA or RNA, but NEVER BOTH • lack the necessary cellular parts that can allow them to • replicate independent of the host cell • lack the genes and enzymes that are necessary for energy production • rely on the cellular machinery of the host cell for protein and energy production • are considered obligate intracellular parasites.

• special type of viruses that primarily infect bacteria • Similar to other viruses in that • (1) they are obligate intracellular parasites • (2) they are similarly shaped like other viruses • (3) they may also be classified based on the type of nucleic acid they possess. • They play a role in the acquisition of virulence factors of certain bacteria - e.g., diphtheria toxin of Corynebacterium diphtheriae • as well as in the transfer of genetic material from one bacterium to another - as in transduction

• are prokaryotic cells • majority having an outer covering called the CELL WALL - composed mainly of PEPTIDOGLYCAN. • they possess both DNA and RNA. • Unlike eukaryotic organisms - possess a NUCLEOID instead of a true nucleus - smaller ribosomes - lack mitochondria • Based on their physical characteristics, bacteria may be broadly categorized into

• Eukaryotic • with an outer surface composed mainly of CHITIN. • cell membrane is made up mostly of ergosterol • fungi possess BOTH DNA AND RNA. • they possess a true nucleus that is enclosed by a nuclear membrane and mitochondria that function for ATP production • Fungal ribosomes are also larger than bacterial ribosomes (80 Svedberg units)

• eukaryotic organisms • outer surface consists primarily of CELLULOSE • described as PLANT like organisms • most of them have CHLOROPHYLL • capable of photosynthesis • vary in size from the single celled PHYTOPLANKTONS to the large seaweeds found in the ocean floor. • do not produce significant disease in humans. • Most are beneficial in that they are important sources of food, iodine, and other minerals • They may also be used as fertilizers, emulsifiers for puddings, and stabilizers for ice cream and salad dressings

• are the representatives for PARASITES • eukaryotic cells • have an outer surface called a PELLICLE • UNICELLULAR organisms that usually divide through binary fission • Majority exist in two morphologic forms • cysts and trophozoites • infective stage • pathogenic stage • Trophozoite • possess BOTH DNA and RNA as well as other cellular features seen in typical eukaryotic cells.

• are unicellular algae that inhabit both fresh and saltwater • cell wall contains silicone dioxide - may be utilized in filtration systems, insulation, and as abrasives • Dinoflagellates - are also unicellular algae that are important members of the phytoplankton group - contribute greatly to the oxygen in the atmosphere - serve as important links in the food chain - they are also responsible for what is known as “red tide.” - produce a powerful neurotoxin - when ingested in significant amounts - responsible for the potentially fatal. disease called paralytic shellfish poisoning.

CAPSID, CAPSOMERES

INFECT BACTERIA

CELL WALL, PEPTIDOGLYCAN

CHITIN, ERGOSTEROL

PARASITES, PELLICLE

CELLULOSE, CHLOROPHYLL

SILICONE DIOXIDE

RED TIDE, NEUROTOXIN