Biology PAP – October 23, 2017 Human Immune System Warm-up: Define the following words in your notebook (pgs. Unit 2.5 in textbook) Human Immune System Nonspecific defenses (pg. 169) Autotrophs (pg. 158) Specific immunity (pg. 169) Chemosynthesis (pg. 158) Cellular immunity (pg. 169) Binary fission (pg. 159) Antibody immunity (pg. 170) Conjugation (pg. 160) Plasmid (pg. 157) Endospore (pg. 160) Pili (pg. 158) Capsid (pg. 164) Flagella (pg. 158) Bacteriophage (pg. 164)

Bacteria

BACTERIA Prokaryotic Cell wall, cell membrane, cytoplasm DNA = in cytoplasm or as a plasmid (circular piece of DNA) Smallest form of life Found everywhere

Shapes of Bacteria

Bacteria can obtain their energy in different ways: Autotrophs - Make own food Chemotrophs - Make food from inorganic compounds Heterotrophs - Obtain food from other organisms Decomposers - Feed on dead materials Bacteria live in a variety of conditions: Obligate Anaerobes - Do not require oxygen Obligate Aerobes - Require oxygen to live Facultative Anaerobes - Can exist with or without O2

Bacterial Reproduction In favorable conditions, bacteria can grow and divide every 10-20 mins Bacteria divide into two bacteria cells = binary fission Some bacteria can exchange genetic material = conjugation Video = Youtube

Nitrogen Bacteria in soil that can convert nitrogen gas into ammonia for plants to use = nitrogen fixation Anaerobic bacteria in soil eventually return nitrogen back to the atmosphere = nitrogen cycle

Probiotics vs. Antibiotics Some bacteria are good and others are bad... E. coli that lives in your intestinal tract, is needed to help digest food Probiotics help promote the growth of bacteria Antibiotics are chemicals that kill bacterial cells or slow down growth

Viruses

Structure = protein capsid, genetic material, tail fibers, tail sheath VIRUS Non-living Structure = protein capsid, genetic material, tail fibers, tail sheath "Lock and key" attachment = fits with the host cell Two reproductive cycles: Lytic or Lysogenic Both require a living host

Lytic Cycle Virus injects DNA into the cell & takes over the cell to make more viral DNA Lysogenic Cycle Virus injects DNA into cell which then fuses with cells DNA

Immune System

HUMAN IMMUNE SYSTEM 1st Line of Defense Integumentary system (skin, sweat, oils, tears, mucus) 2nd Line of Defense Inflammatory response (and fever) Specific Immunity Recognize cells as healthy / unhealthy Antigens trigger immune response Cellular Immunity - T-cells (helper, killer & memory) [WBC] Antibody Immunity - B-cells (memory and antibodies) HIV - attacks T cells Vaccines - acquired immunity

Immunity Innate immunity = born with Acquired immunity = once exposed to a pathogen, the body learns Immune system works with the integumentary system & circulatory system to block & prevent invaders from harming the body Fevers causes WBCs to mature faster & creates an unfavorable environment for invaders Vaccinations = prevent disease / jump start to the immune system