Bacteria Flashcards
(30 cards)
List the 6 features of Bacteria
- Unicellular prokaryotes
- No nucleus
- DNA floats in the cytoplasm
- Reproduce via Binary Fission
- No mitochondria Rigid
- Presence of a cell wall
What is the Bacteria cell wall made of?
Layers of Peptidoglycan
How are bacteria classified?
- Gram staining
- Food source
- Energy Source
What is the name of Bacteria that gets food from an outside source? Explain how they get there energy and give an example.
Heterotrophs - These bacteria get energy from breaking down organic compounds.
Saprobes.
Used for classification, what are the two energy classifications?
Phototrophs & Chemotrophs
What are the names for the 3 ways in which bacteria has a relationship with Oxygen?
- Obligate Aerobes
- Obligate Anaerobes
- Facultative Anaerobes
What does Aerobic mean?
This is a class of bacteria that uses oxygen for respiration. Without it the bacteria would die.
What does Anaerobic mean?
This is the class of bacteria that in the presence of oxygen would die, using anaerobic respiration instead.
What does Facultative Anaerobes mean and give an example?
This is where a bacterium in primarily Aerobic but in the absence of Oxygen, can switch to Anaerobic respiration.
Coliform Bacteria
What are the 5 shapes of Bacteria?
- Spherical - Cocci
- Rob - Bacilli
- Spiral - Spirilla
- Comma - Vibrios
- Corkscrew - Spirochaetes
What are the names given to the 6 arrangements of Cocci?
- Coccus
- Diplicocci
- Staphylococci
- Streptococci
- Sarcina
- Tetrad
Give and example of a condition caused by Vibro bacteria
Septicemia
What are the 7 major structures of a bacteria cell?
- Capsule/ Slime layer
- Cell wall
- Ribosomes
- Nucleoid
- Flagella
- Pilli
- Cytoplasm
What is the function of the capsule/slime layer and what is its proper name?
The slime layer is to enable the bacteria to stick to surfaces.
The capsule is to protect the bacteria.
The bacteria cell with not have both capsule & slime layer.
Glycocalax
What do Ribosomes do?
Create proteins
what are plasmids?
Circular - non coding- DNA, separate from the main nucleoid
What is gram staining?
It is where Crystal violet stain is used to identity which group of bacteria a specimen belongs to.
What is gram positive bacteria?
This is where the bacteria does not have a double membrane allowing the crystal violet stain to stain the cell wall.
What is gram negative bacteria?
This is where the bacteria does have a double membrane thus preventing the crystal violet staining from reaching the cell wall.
How do bacteria reproduce?
Asexually and divides through Binary Fission.
What are the 4 stages in the bacteria reproduction cycle?
- Lag phase - slow start
- Exponential growth - where reproduction is very fast
- Stationary phase - Where there is a flat line, all nutrients used or build up of waster
- Death phase - Bacteria start to die due to starvation.
How are bacteria counted?
A haemocytometer is a grid of microscopic chambers each with a know area and depth
Name the 3 method used by bacteria to transfer plasmids/genetic material?
Transformation - it just picks up floating DNA
Conjugation - Pilli - Sex
Transduction - virus infects one and then infects another.
What is Conjugation?
Where the exporting bacterium grow a tube called a pillus. This inserts into the receiving bacterium. A strand of the DNA uncoils from the plasmid and travels down the pillus into the receiving bacterium.
