Bacteria
A Typical Bacterium usually consists of
A cytoplasmic membrane surrounded by a peptidoglycan cell wall and maybe an outer membrane a fluid cytoplasm containing a nuclear region (nucleoid) and numerous ribosomes; and often various external structures such as a glycocalyx, flagella, and pili.
Bacterial Reproduction Stage # 1
Bacterial Chromosomes replicates and cell enlarges
Transformation Step # 2
Bacterial enzymes cut the DNA into smaller fragments.
Bacterial Reproduction
Binary fission
Fertiliity Factors
Carry several genes that required for conjugation and also may carry genes that confer growth advantage
Reproduction Stage # 4
Cell division is completed.
Stage # 2 (Reproduction)
Cells begin to divide
Resistance plasmids (R factors)
Confer resistance against antibiotics and other types of toxins
Bacterial Ribosomes
Consist of RNA plus protein Sites of protein synthesis
Transformation
DNA released from a dead bacterium into the environment is taken up by another bacteria
Conjugation
Direct physical interaction transfers genetic material from donor to recipient cell
Galactamase
Enables bacteria to become resistant to antibiotics.
Bacterial Chromosomes
Molecules of double-stranded DNA Usually Circular Tend to be shorter Contains a few thousands of genes Mostly structural genes Single origin of replication
Transduction Step # 3
New phages are made. Occasionally a phage carries a piece of the host cell chromosome, such as the his+ gene
Transformation Step # 3
One strand is degraded, and a single strand is imported into the cell by a DNA uptake system.
Transduction Step # 1
Phage P1 infects a bacterial cell, which is his+.
The Bacterial Cell Wall
Protection from osmotic lysis Provides shape to the bacteria, which endows cells to be cullus, spiral, and causus. In direct contact with the environment Pathogenesis Cell wall contain peptidoglycans cross-linked by polypeptides.
Conjugation Step # 2
Proteins of the donor cell transfer the separated DNA strand to the recipient cell.
Quorum Sensing
The ability of bacteria to sense the presence of other bacteria via secreted chemical signals.
Transduction Step # 2
The host DNA is hydrolyzed into pieces
Transformation Step # 4
The imported DNA is incorporated into the bacterial chromosome, and the complementary strand is made.
Conjugation Step # 1
The sex pilus shortens and draws cells closer together. A conjugation bridge is formed that provides a passageway between the two cells. One strand of the F factor DNA is cut by an enzyme at the origin of transfer and begins separating from the other strand.
Transduction Step # 5
The transduced DNA is recombined into the chromosome of the recipient cell, thereby introducing the his+ gene into the chromosome.
Transduction Step # 4
The transducing phage injects its DNA into a new recipient cell, which is his-.
Bioremediation
The use of living organisms to detoxify and restore polluted and degraded ecosystems.
Single origin of replication
There is a DNA Sequence needed to create a copy of the bacteria. Mostly bi-directional. Eukaryotes have multiple origins of replication since their cells are huge.
Bacterial Chromosomes usually
Transcribe and translate at the same time
Plasmids may replicate independently
True
Transduction
Viruses that infect bacteria can transfer bacterial genes from one bacterium to another
F-Pillus is attached to the F-Minus so
a bridge can form and that one strand of the DNA is transformed into the f- strain.
Only about 5% of E. coli strains found in nature can
act as donor strains
Virulence plasmids
carry genes that cause disease
Degradative plasmids
carry genes that enable the bacterium to digest and utilize an unusual substance
One of the first things needed to be chopped up is
chromosomal DNA since they need viral DNA
Competent Cells
competent factors are capable of transformation
Donor Strains
contain a fertility factor ( F-Factor) that can be transferred to recipient strains
2 Strept Ammonia would lead to
death
Col-plasmids
encode colicins that can kill neighboring bacteria
Some strains are hTF
for high frequency of recombination
Vertical Gene Transfer
genes are passed from one generation to the next among individuals of the same species.
Bacteria can secrete hormones that can increase cell number, telling the bacteria
having the molecule talking to them, and letting all the bacteria to turn on light.
Sex Pili
made by F+ cells that bind specifically to F- cells
Spiral Bacteria
motile bacteria having a helical or spiral shape
Photoheterotroph
organism that is photosynthetic but needs organic compounds as a carbon source
Chemoheterotroph
organism that must take in organic molecules for both energy and carbon
Photoautotroph
organism that uses energy from sunlight to convert carbon dioxide and water to carbon compounds
Cell Wall is made of?
peptidoglycan
Episome
plasmid that can integrate into bacterial chromosome
Obligate anaerobes
poisoned by O2 and use fermentation or anaerobic respiration.
Onbligate aerotes
require O2 for cellular respiration
Baracilli
rod-shaped bacteria
Plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome. Occur naturally in many strains of bacteria and in a few types of eukaryotic cells, such as yeast Own origin of replication that allows it to replicated independently of the bacterial chromosomes Not usually necessary for survival but can provided growth advantages.
Bacteria can also interact with other proteins that are either
specific( Intraspecific) or have other proteins that can bind to other chemicals( Interspecific).
Facultative Anaerobes
survive with or without o2.
When injecting rough ammonia into the gene
the mouse survived.
When the mice died, they found a colony of smooth strpt and rough trept ammonia. Basically,
the rough strept become the smooth strept ammonia.
How many species of bacteria can be found on Earth?
thousands of bacteria, where they are abundant of size.
Transformation Step # 1
A DNA fragment containing the tetR gene binds surface receptoto a cell r.
Reproduction Stage # 3
A cell wall is formed between 2 cells
17% of genes in E. coli and Salmonella typhimurium have been acquired
Horozontal gene transfer
biofilms
In some prokaryotic species, metabolic cooperation occurs in surface-coating colonies
Heterocysts
In the cyanobacterium Anabaena, photosynthetic cells and nitrogen-fixing cells
Conjugation Step # 3
In the donor cell, the remaining F factor DNA strand is used as a template to synthesize a complementary strand. In the recipient cell, an enzyme joins the ends of the transferred DNA strand, and the complementary strand is made. Each cell now has a double-stranded circular F factor.
Chemeoautotrph
Inorganic chemicals as their energy source.
Transformation
Living bacterial cell imports a strand of DNA that another bacterium released into the environment when it died
One F+ and one F-, leading to
2F +
Coccus
A spherical bacterium.
Transduction
A virus transfers genetic information from one bacterium to another
Fertility plasmids (F factors)
Allow bacteria to mate with each other
Genetic Properties of Bacteria
Genes of bacteria are found in bacterial chromosomes Usually a single type of chromosome May have more than one copy of that chromosome Number of copies depends on the bacterial species and on growth conditions Typically 1-4 identical chromosomes Nucleoid - region where tightly packed bacterial chromosome found
2 Types of Strept Ammonia
Smooth and Rough
Grand Stain
Stain where they come with an infection. Determines if its grand positive or negative.
