Pathogens: An organism that causes disease. (Chp. 18/chp.39) see p.550
Types of Diseases Contagious…if it spreads quickly
• Non-communicable Disease: cannot be transmitted from one person to another
• Heart attach• Depression• Stroke• Hypertension/hypo.
• Cancer• Genetic disorders (only
to their children)
• Communicable Disease: can spread from one person to another
• Diarrhea• Pneumonia• Tuberculosis (TB)• Sexually transmitted
diseases (STD’s)
Bacteria• Unicellular and everywhere• Some damage cells and tissues
• Others release Toxins: poisons that travel through the body and may cause diseases
• There are environmental toxins: Lead and Mercury
Other toxins:Botulism> improperly prepare food
Disease Bacterium Effect on Body
Strep Throat Streptococcus Fever, sore throat swollen neck glands
Tuberculosis Mycobacterium Fatigue, weight loss, mild fever, chronic cough
Tetanus Clostridium tenani Muscle spasms, paralysis, death
Lyme Disease Borrelia burgdorferi Rash at site of tick bite, fever, chills
Bacterial Meningitis Neisseria meningitidis
High fever, headache, stiff neck, nausea
Diphtheria Corynebacterium diphtheria
Sore throat, low-grade fever
Diseases Caused by Bacteria
Viruses: Nonliving..Must have a LivingHost
• Consist of genetic material enclosed in a protein coat (Capsid [head], nucleic acid, Sheath, Tail)
• Bacteriophage (phage): a virus that infects a bacterium. The virus will attach its legs to a cell and then inject its genetic material into it. The virus takes control of the bacterial cell and directs it to produce viral material. A single infected cell may replicate thousands of viruses.
A typical Bacteriophage, a type of virus
Attaches to a cell
Protein coat
Viruses Cause….
• HIV• Influenza• Chickenpox• Colds• Measles• Rabies
Viral Replication Cycles p. 478/479
• (1)Lytic Cycle: immediately takes over killing the host cell
• (2) Lysogenic Cycle: does not kill host cell immediately integrates its genetic material with the host cell…creates a provirus…..sits dormant….then one day takes over the host
Viral Replication Cycles
Top Related