Metabolism in bacteria Flashcards
Uses carbon dioxide as the sole source of carbon, with only water and inorganic salts required in addition.
Autotrophs
Requires an organic source of carbon, such as glucose, and obtain energy by oxidizing or fermenting organic substances.
Heterotrophs
For making cellular constituents.
[sources]
source of carbon.
For making proteins.
[sources]
source of nitrogen.
Adenosine triphosphate [ATP], for performing cellular functions.
[sources]
source of energy
Forms part of the structure of several coenzymes and is found in the cysteinyl and methionyl side chains of proteins.
Sulfur
It is always assimilated as free inorganic phosphate (Pi).
Phosphate
It is a consequence of growth.
Cell multiplication
Time required for one cell to divide into two cells is called.
generation time or doubling time
Four phase of Growth.
- lag phase
- log phase
- stationary phase
- death phase
Bacteria are preparing to divide and adapt to their new environment.
[phase]
Lag phase
Bacteria numbers increase logarithmically.
[phase]
Log phase
Nutrients are becoming limited and the numbers of bacteria remain constant.
[phase]
Stationary phase
When the number of nonviable bacterial cells exceeds the number of viable cells.
[phase]
Death phase
[3] Determination of cell numbers.
- Direct counting under the microscope.
- Direct plate count
- Density measurement.
pH: neutral
- neutralophiles
- acidophiles
- alkaphiles
7.0 to 7.5
[pH: neutral]
neuralophiles
<6.5 to 3.0 up to 1.0
[pH: neutral]
acidophiles
> 8.0 to 10.5
[pH: neutral]
alkaphiles
[4] Temperatures
- psychrophilic
- mesophilic
- thermophilic
- hyperthermophilic
15–20 °C
[temp]
psychropilic
30–37 °C
[temp]
mesophilic
50–60 °C
[temp]
thermophilic
> 100 °C
[temp]
hyperthermophilic
The killing of cells by rapid cooling.
Cold shock
Require oxygen for growth.
Obligate aerobes
Can survive in the presence of oxygen but do not use oxygen in metabolism.
Aerotolerant anaerobes
Cannot grow in the presence of oxygen.
Obligate anaerobes
Can grow either with or without oxygen.
Facultative anaerobes
Organisms grow best when the atmosphere is enriched with extra carbon dioxide (5% to 10%).
Capnophilic
Bacteria require a reduced level of oxygen to
grow.
Microaerophilic
Organisms requiring high salt concentrations.
Halophilic
Requiring high osmotic pressures are called?
Osmophilic
During the loss of water, the cytoplasmic membrane collapses away from the cell wall, which is called?
Plasmolysis
Consists of the biochemical reactions bacteria use to break down organic compounds and the reactions they use to synthesize new bacterial parts from the resulting carbon skeletons.
Microbial metabolism
An efficient energy generating process in which molecular oxygen is the final electron acceptor.
Respiration
They carry out aerobic respiration, in which oxygen is the final electron acceptor.
Obligate aerobes
