bacteria and viruses

Bacteria and Viruses

What is a prokaryote? Microscopic Usually ____________ celled Usually have a cell wall, but no

membrane bound organelles

Prokaryote vs. Eukaryote Cells

Archaea Bacteria “Ancient” bacteria Cell walls are chemically different than

other bacteria Found in extreme conditions ex. Yellow

stone national park hot springs.

Characteristics of Bacteria Single celled Can be producers, consumers, and

decomposers. Live everywhere ie. Ubiquitous

Bacteria Shapes Three Shapes

1. Rod- ___________2. _______ -coccus3. Spiral- spirallus

Reproduction Binary fission- divides in half producing

two ___________ “daughter cells”

How do bacteria exchange DNA? Three ways1. Transformation – takes in DNA from the

environment2. Transduction- happens when a virus

injects DNA into a bacterium 3. Conjugation- DNA is transferred from

one bacterium to another when two bacteria are joined together

Bacteria Structure and FunctionOverview 1. Cytoplasm 2. Chromosome 3. Ribosome 4. Cell Wall 5. Gelatin Capsule 6. Flagellum

cytoplasm Gelatin-like, flows inside cell

Contains everything cell needs to carry out life

chromosome (genetic material)

Directs cell activities

Provides directions for all cell processes

ribosome Makes protein

cell membrane

Controls what goes in and out of the cell

Separates cell from its environment

cell wall Supports and

protects the cell

gelatin like capsule Protects cell Allows bacteria to

stick to surfaces

Prevents bacteria from drying out

flagellum (plural: flagella)

Whip-like tail that helps cell to move

Virus Basics Virus are typically composed of a core of

_____ or _______ surrounded by a ____________

Can reproduce only by infecting _______________

Controversial- living or nonliving

Structure

________ -protein coat includes proteins that enable viruses to enter the host cell Bacteriophages- viruses that infect

bacteria ________ -viral DNA embedded into host’s DNA

Virus Structure Cont

Viral Infections

Living or DeadLiving Evidence Dead EvidenceObtain and use _____________ Missing many characteristics

common to life ie. cell structure, does not respond to stimuli.

Contains _______________ and proteins.

Cannot survive or reproduce without a host cell

Does not perform life functions