Microbial Metabolism Flashcards
What did Pasteur discover?
That aerobic growth conditions produced more yeast when compared to anaerobic growth conditions
Does aerobic respiration produce a high or low ATP yield?
High
Following glycolysis, pyruvate is oxidised to form acetyl CoA which begins the Krebs cycle.
The products are ATP and CO2
Does anaerobic respiration produce a high or low ATP yield?
Low
Following glycolysis, pyruvate is reduced to form lactate (which goes on to form lactic acid) or is converted to acetaldehyde and then to alcohol (fermentation)
What is fermentation?
The method by which anaerobes grow
There is no/ limited oxygen availability
Bacteria and yeast ferment carbohydrates
We can use the byproducts of fermentation for wine and vinegar
Why do microbes require energy?
To grow, move, reproduce, maintain cell structures and for defence against threats
Which three pathways are used by microbes to absorb nutrients?
Diffusion
Facilitated diffusion
Active transport
Define autotroph
An organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide.
They acquire carbon via CO2
Define heterotroph
An organism deriving its nutritional requirements from complex organic substances.
They acquire carbon from amino acids, sugars, fatty acids, organic acids, aromatic compounds and nitrogenous bases
Define photoautotrophic
Photoautotroph are organisms that carry out photosynthesis. Using energy from sunlight, carbon dioxide and water are converted into organic materials to be used in cellular functions such as biosynthesis and respiration
An example is rhodospirillium rubric
Define photoheterotrophic
Photoheterotrophs are heterotrophic phototrophs – that is, they are organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source
An example is Rhodobacter sphaeroides
Define chemoautotrophic
An organism, typically a bacterium, which derives energy from the oxidation of inorganic compounds.
An example is Thiomicrospira denitrificans
Define chemoheterotrophic
Chemoheterotrophs are chemotrophs that are heterotrophic organisms. They are not capable of fixing carbon to form their own organic compounds. Most chemoheterotrophs obtain energy by ingesting organic molecules like glucose
An example is lactobacillus acidophilus
Give an example of how essential nutrients are used
Phosphorus- phospholipids, nucleic acids
Sulphur- amino acids, vitamins, enzymes
Potassium- enzymes for protein synthesis
Give an example of how non-essential nutrients are used
Calcium- stabilises cell walls
Give an example of how trace elements are used
Colbalt- enzyme production
Selenium- amino acid synthesis
Tungsten- amino acid synthesis
