Kingdom Bacteria Flashcards
(19 cards)
What are bacteria the most
Heterotrophs
1.Obligate aerobe=
2.Obligate anaerobic=
3.Facultative aerobes=
- Need oxygen
- Can’t survive in the presence of oxygen
- Can live with or without oxygen
Characteristics of bacteria
Gram positive and gram negative
Gram positive
A thick and spongy protein layer that turns purple when stained.
Gram negative
Thin protein layer that stains pink
Bacterial shapes
Coccus
Spirillum
Bacillus
Bacterial reproduction
Asexual reproduction by binary fission
Binary fission
A parent cell splits into two new cells, and each gets an exact copy of the parent’s DNA.
Sexual reproduction
Bacteria connect using tiny structures called pili and share genetic information.
Transformation
A cell takes in a piece of DNA from its surroundings and uses it.
Some bacteria go into a resting phase during bad conditions, called an
Endospore
Endospore
A tough structure forms around the chromosomes to protect them from extreme conditions.
They wait to reproduce until conditions are good.
Roles of bacteria
Decomposition
Pathogens
Mutualism
Decomposition
They break down materials in ecosystems and help recycle important elements like carbon and nitrogen.
Pathogens
Bacteria are tiny living things that can make people, plants, and animals sick. They can create harmful substances called toxins that can cause illness.
Mutualism
Roles with humans
(Bacteria in large intestine produce vitamin k and b12)
Bacteria and antibiotics
Antibiotics are like medicines that fight against bacteria. They work by stopping the bacteria from growing and making more of themselves. This helps to prevent the bacteria from building their cells or creating DNA or RNA.
Bacterial growth rate
-Bacteria reproduce via binary fission
-Under favourable conditions they can divide every 20 min
-this is called exponential growth
Antibiotics resistance
-Bacteria reproduce fast, which can cause changes in their genes.
-These changes can make antibiotics less effective. To deal with this, we need to: change where the drug works, change the drug’s structure
-some plasmids have genes for antibiotic resistance.
