Exam 1: Bacterial Nutrition and Growth Flashcards
(53 cards)
Why do we care about bacterial nutrition?
It affects how we grow bacteria in the lab
It affects how we differentiate type of bacteria
It is the underlying fundamental reason for bacterial infection
What do all cells, including bacteria, require to grow?
A source of carbon and energy Nitrogen Phosphorus Sulfur Sodium Potassium Iron Magnesium Manganese Traces of other minerals
How do bacteria adapt to their surrounding environment?
Maximize their reproductive capability by minimizing the amount of energy they have to invest in synthesizing all the nutrients they need to live
What are the 3 major nutritional categories of bacteria?
Photosynthetic
Autotrophic
Heterotrophic
Describe photosynthetic bacteria
Can use light as the sole source of energy for growth and carbon fixation from carbon dioxide
No pathogens
Describe autotrophic bacteria
Can use inorganic molecules as the sole energy source and may use carbon dioxide or other organic molecules as a carbon source
No pathogens
Describe heterotrophic bacteria
Cannot use inorganic molecules as the sole source of energy and cannot use CO2 as the sole source of carbon
Use organic molecule as a source of carbon and energy
How are all the complex molecules require for life for heterotrophic bacteria obtained?
By either synthesis from simpler molecules or salvage from the environment
Which takes less energy, salvaging nutrients or synthesizing them?
Salvaging nutrients
What is the basic carbon source used to synthesize biomolecules?
Glucose
What can some heterotrophs grow on?
Glucose, ammonium, and phosphate ions with trace minerals
What does glucose serve as for heterotrophs?
As the energy source and the carbon source for the synthesis of nucleic acids, proteins, lipids, and carbohydrates
What do fastidious microorganisms require?
Preformed nutrients in the growth medium
Why do most bacterial species require other nutrients besides glucose?
They are missing enzymes in one or more biosynthetic pathways
What can some bacteria do when glucose is not available?
Utilize other biomolecules as energy/carbon sources by converting them into glucose
What is always going to be the preferred energy/carbon source? Why?
Glucose
It costs energy to convert other molecules into glucose
What is commonly used to taxonomically identify bacterial species?
The alternative energy sources bacteria can use that is conserved within species
What are essential nutrients required for?
Cell growth
What are the essential nutrients required by all heterotrophic bacteria?
Carbon source (glucose or an alternative if glucose is absent)
Nitrogen source
Other minerals
What are the nutrient requirements specific for each species based on?
What they are not capable of synthesizing
What do nonessential nutrients require?
Any molecules that a bacteria is capable of synthesizing, but will salvage if available
What are the types of heterotrophic bacteria?
Saprophytic
Parasitic (obligate parasites)
Both (facultative parasites)
What do saprophytic bacteria do?
Utilize dead or decaying organic material for carbon/energy sources
What do parasitic bacteria do?
Obtain nutrients directly from other living organisms
