Topic 3: Bacteria Flashcards
What does it mean when we say Bacteria can be pathogenic?
means that bacteria can cause disease
How does pathogenic bacteria make us sick?
By producing toxins and damaging tissues that lead to you feeling sick.
How do bacteria reproduce? How many cells does it require?
Binary Fission. Requires 1 cell.
How often does binary fission happen?
Every 20 minutes.
How does the cell split in Binary Fission?
They copy their DNA and then the chromosome attatches to the cell membrane that creates a new cell wall plate, splitting the cell into two - each with its own DNA.
What is a gram stain?
A gram stain identifies different types of bacteria. It identifies the thickness of the cell wall (amount of peptidoglycan) by the different colours of pink and purple.
What does a gram stain show about bacteria?
- Bacteria is positive or negative
- The cell wall structure. (+) = thick peptidoglycan (-) = thinner peptidoglycan
- The shape and arrangement of bacteria
- Type of Bacteria present
Gram Positive (+)
- DARK PURPLE
- large amount of peptidoglycan (thick cell wall)
Gram Negative (-)
- LIGHT PINK
- less amount of peptidoglycan (thin cell wall)
List 3 reasons why bacteria grows so fast on agar plates?
- It is full of nutrients that provide essential growth for bacteria. Sugars, proteins and water as a food source.
- Kept at a suitable temperature of 37 degrees that promotes bacterial growth
- It has a large surface area for bacteria colonies to grow.
How are bacteria infections treated?
Antibiotics that target specific bacteria. Some work on Gram P, some work on Gram N.
What do antibiotics do to bacteria specifically?
- Target bacterial structures such as cell walls blocking cell wall synthesis or rupturing the cell wall
- stop bacterial enzymes working, slowing down bacterial reactions
- bind to the surface of thr bacterial cell alerting it as foreign
Give 2 examples of Antibiotics
- Penicillin
- Ampicillin
Why is antibiotic-resistant bacteria a big threat to our health?
- Are not controlled, are fast spreading
- We can’t develop antibiotics fast enough to deal with these emerging superbugs that are killing many patients.
How do bacteria resist antibiotics?
- They have a pump to remove the antibiotic
- Produce an enzyme to breakdown the antibiotic
- Produce a thicker cell wall making it hard for the antibiotic to enter.