Premed - Lecture 8. Bacterial Genetics

Front 1

Pairing of Generic Information
List the 2 pairs

Back 1

Adenine - Thymine
(2 hydrogen bond)

Guanine - Cystosine
(Hydrogen bond)

Front 2

What is the smallest bacteria called?

Back 2

Mycoplasma (475 potential genes)

Front 3

A typical Bacteria is:

Back 3

Escherichia Coli
(4288 potential genes)

Front 4

Why are bacteria highly adaptable (3 things)

Back 4

1. Mutation
2. Genetic material exchange
3. Transposons

Front 5

Define: Mutation:

Back 5

Is a change in the base sequence of DNA
Results in a change of codon leading to amino acid sequence change in encoded protein.
Reproduce fast, some divide within 20 minutes
Change can be because of loss/ gain of DNA segment (addition or loss of a single base)

Front 6

Where does genetic material exchange take place (between what?)

Back 6

Between bacterial cells.

Front 7

Define Transposons:

Back 7

Jumping genes.

Front 8

What is the most common way / fastest way to exchange and transfer?

Back 8

Genetic Material Exchange.

Front 9

What are 2 causes of mutation?

Back 9

1. spontaneous (enzyme errors)
2. induced (mutagens)

Front 10

What are the three ways of DNA transfer?

Back 10

1. Transformation
2. Transduction
3. Conjugation

Front 11

Donor give a part of its DNA to the ___

Back 11

recipient

Front 12

Unidirectional means when the Donor give

Back 12

To the Recipient

Front 13

Define: Transformation

Back 13

- thorough or dramatic change in form or appearance.
- follwoing death of bacterium, free DNA is released into the environment. close bacteria may take up some of the DNA, may have a double crossover and incorporate new DNA to replace the original chromosomal DNA

Front 14

Define: Transduction

Back 14

the process of transfering genetic material from one cell to another by a plasmid or bacteriophage, virus that infect bacteria
(from a donor to a recipeint)

Front 15

Define: Conjugation

Back 15

Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells....
- Transfer of plasmid into the chromosomal structure in the recipient

Front 16

Gene transfer in plasmids from a donor to a recipient by direct physical contact between cells is know as:

Back 16

Conjugation

Front 17

Mating types in bacteria through sex pili (recipient) lacks

Back 17

an F- factor

Front 18

Mating types in bacteria through sex pili (donor) has

Back 18

F factor (fertility F+) incorporated with its chromosome.

Front 19

The Donor in (sex pili) has a transmissible plasmid that -

Back 19

carries genes such as antibiotic resistance or virulence genes.

Front 20

When there are a lot of F+ together, they secrete products that are:

Back 20

transcription

Front 21

HFR plasmid means:

Back 21

High Frequency Plasmid

Front 22

The two types of transduction are:

Back 22

1. Generalized
2. Specific

Front 23

Basic Structure of Bacteriophage, parts and functions:

Back 23

Head (ischohedral structure containing phage DNA).
Neck + Collar
Body (sheath surrounding tubular core)
Long legs (long tail fibers)
Baseplate
Short Legs (short tail fibers)

Neck body compresses and the DNA gets squirted into the cell and reporduce in the cytoplasm of the cell

Front 24

What is the Process of generalized transduction:

Back 24

- random fragments of host DNA infect accidentially (take up virus)
- virus kills cell, enters another, carries new gene, new host survives, phage is defective

Front 25

Why is the phage deficient in generalized transduction:

Back 25

does not pick up bacterial host DNA (has to leave DNA behind).
cell does not die, but is defective

Front 26

In generalized transduction, A lytic bacteriophage adsorbs to a:

Back 26

susceptible bacterium

Front 27

In generalized transduction, bacteriophage genome enters the bacterium. The genome directs the bacterium's metabolic machinery to:

Back 27

manufacture bacteriophage components and enzymes.

Front 28

In generalized transduction, sometimes during maturation, a bacteriophage head or capsid assembles:

Back 28

around a part of donor bacterium's nucleoid or around a plasmid instead of a phage genome.
By mistake.

Front 29

Describe what happens in Specialized Transduction:

Back 29

- phage DNA enters bacterial DNA in a special spot.
- takes some host genes and leaves some of it own.
Other normal phage kill host, all viruses leave
- defective phage can transfer host gene to new bacterium

Front 30

Steps in Specialized Transduction:

Back 30

1.A temperate bacteriophage adsorbs to susceptible bacterium and injects its genome.
2. The bacteriophage inserts its genome into the bacterium's nucleoid to become a prophage.

Front 31

What happens as the bacteriophage replicataes in specialized transduction?

Back 31

The segment of bacterial DNA replicates as part of the phage's genome. Every phage now carries that segment of bacterial DNA.
- The new bacteriophage adsorbs to a recipient bacterium and injects its genome.

Front 32

What are transposons?
Define + list 4 key points.

Back 32

Transposons are sequences of DNA that can move or transpose themselves to new positions within the genome of a single cell.
- small fragments of DNA large enough to hold genes for their replication and replication of others.
- can integrate and excise and take their gene to another place while leaving itself behind
- can move to adn from any DNA (phage, plasmid, bacterial genomes, and can move key genes like anitmicrobial resitance)
- smallest transposons have only self genes and are called insertion sequences.