Metabolic pathways

metabolic pathways

may be useful in classification

1. autotrophs

2. heterotrophs

3. phototrophs

4. chemotrophs

heterotrophs

other feeders

phototrophs

energy from sun

chemotrophs

oxidizes inorganic or organic chemicals

photoautotrophs

plants and cyanobacteria are classified as

obligate aerobes

require O2 for ATP generation in cellular respiration

facultative anaerobes

can live either with or without O2

1. uses fermentation to generate ATP

2. ex. E. coli, samonella

obligate anaerobes

O2 is toxic to them therefore they live in environments that lack it

1. Use fermentation to generate ATP

3 domains

Molecular data reveals evolutionary relationships. The DNA sequence encoding ribosomal RNA (rRNA) suggest that there are how many domains?

vertical gene transfer

prokaryotes transfer DNA generation to generation

1. binary fission reproduction

horizontal gene transfer

complicates classification

1. prokaryotes can obtain new DNA through this rather than from an ancestor

2. Happens in three ways

   1. transformation

   2. transduction

   3. conjugation

transformation

A dying cell may release it’s genetic material as it bursts

1. { } occurs when a cell absorbs stray pieces of DNA

transduction

Virus mistakingly packages host cell DNA along with their own

1. { } occurs when a virus transfers this combined DNA to a bacterial cell

conjugation

{ } occurs when one cell receives DNA via direct contact with another cell

1. sex pilus

sex pilus

an appendage through which DNA passes from donor to recipient