bio 134 chapter 18 bacteria and viruses - sps186.org 134 chapter 18 bacteria...what do eubacteria...
Post on 06-Apr-2019
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Main idea
! Bacteria are prokaryotic cells
Prokaryotic – no nucleus Eukaryotic – DNA contained in a nucleus
Archaebacteria Diversity:
! Halophiles – live in very salty environments
! Methanogens – cannot live in presence of oxygen
What is a capsule?
! A layer of polysaccharide around a cell wall Helps cell from drying out Protects cell
What is the pili?
! Hair-like structures that are made of protein Help bacterial cells attach to surfaces
What are the three different shapes of bacterial cells?
! Cocci – spherical or round ! Bacillus – rod-shaped ! Spirilli – spiral shaped
What do flagella do?
! Help prokaryotes move toward light, oxygen, or chemicals they need to survive
How do chemoautotrophs obtain nutrients?
! They break down inorganic compounds such as ammonia and hydrogen sulfide
What are three important uses of bacteria?
1. Nutrient cycling and nitrogen fixation 2. Normal flora 3. Foods and medicines
Normal Flora
! Bacteria that live in or on you Most are HARMLESS Type of E. coli that live in your intestines
that help break down food
What foods and medicines are made from bacteria?
! Cheese ! Yogurt ! Buttermilk ! Pickles ! vitamins
Name 3 diseases caused by bacteria:
! Strep throat ! Pneumonia ! Types of food poisoning ! Bacterial meningitis ! Lyme disease
Main idea
! Viruses are smaller and less complex than bacteria – they invade cells and can alter functions
What is the lysogenic cycle?
! The viral DNA enters the nucleus of the host cell and becomes a part of the host cells DNA
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