This preview shows page 1. Sign up to view the full content.
Unformatted text preview: es and eukaryotes
(1) Lack compartmentalization by internal membranes
nothing inside cells (2) Many have infolded regions of the plasma membrane
increase surface area for chemical reactions to take place (invagination) (3) Smaller simpler genomes ~1/1000 as much DNA
double-stranded circular DNA nucliod single, circular DNA have smaller rings of DNA - plasmids
needed for special contingencies
genes for antibiotic resistance
metabolize organic material-some sort of sugar?
can be transferred between partners
take bacteria-place into plasmids-able to transfer (4) Ribosomes smaller & differ in protein
content can be selectively targeted because they differ
expressing proteins-assembled on ribosome Certain antibiotics such as erythromycin and bind to prokaryotic ribosomes and
block protein synthesis. Reproduction
Reproduce asexually by binary fission
no mitosis or meiosis grows and splits in half NOT ACTUAL SIZE Growth- refers to increase in population size
With unlimited resources growth is geometric
Generation times:1-3 hours; some double every 20 min.
Can reach incredible densities - 100x109/ mL in human
colon VERY successful because of diversity Mutation is major source of genetic variation
Short generation times and large populations - favorable
mutation can propagate rapidly
depends of mutation rates Very rapid adaptation to environmental change
Horizontal Gene Transfer - Bringing together DNA
from different individuals transfer between different prokaryotes
- facilitates rapid evolution
Prokaryotes have 3 mechanisms that can function to
transfer genes between individuals. (1) Transformation - cell takes up genes from
surrounding environment (one strain transformed into another)
relationship between DNA and genetic material; showed strep bacteria- one dead
and one alive; can transfer the dead one to alive one and picks up bacteria (2) Conjugation - direct transfer of genes from one
prokaryote to another usually between same species
(3) Transduction - viruses transfer genes from one
prokaryote to another
viruses that affect only bacteria - bacteria fages?
virus transfer via one bacteria to another Prokaryotes can withstand harsh conditions
Some form resistant cells – endospores, when
essential nutrient in environment is lacking.
Endospores can withstand boiling water and can
everything dies but endospore and can stay in
remain dormant for centuries. condition for hund...
View Full Document
This document was uploaded on 03/02/2014 for the course BIO 109 at University of Missouri-Kansas City .
- Spring '12