1What are nutritional classifications based on?
An organism's energy source and carbon source.
2What does an organism's energy source tell us?
How it obtains energy to make ATP.
3What does an organism's carbon source tell us?
Where it obtains the carbon used to build organic molecules.
4What is an autotroph?
An organism that obtains carbon from inorganic sources such as carbon dioxide.
5What is a heterotroph?
An organism that obtains carbon from organic compounds made by other organisms.
6What is a phototroph?
An organism that uses light as its energy source.
7What is a chemotroph?
An organism that obtains energy from chemicals.
8What is a photoautotroph?
An organism that uses light for energy and carbon dioxide as its carbon source.
9What are examples of photoautotrophs?
Plants, algae, and cyanobacteria.
10What is a chemoheterotroph?
An organism that obtains energy from chemicals and carbon from organic compounds.
11What organisms are commonly chemoheterotrophs?
Animals, fungi, protozoa, and many bacteria.
12Can animals carry out anaerobic respiration?
No. The lecture distinguishes animal fermentation from anaerobic respiration.
13Which groups can carry out anaerobic respiration?
Bacteria and archaea, and potentially some yeasts.
14What is the difference between aerobic and anaerobic respiration?
They use different final electron acceptors; aerobic respiration uses oxygen.
15What is fermentation used for?
It allows cells to continue generating ATP without using an electron transport chain as in respiration.
16What is a culture medium?
A nutrient preparation used to grow microorganisms.
17What is a broth?
A liquid culture medium.
18How is solid culture medium made?
A liquid medium is combined with a solidifying agent such as agar or gelatin.
19Why is solid medium useful?
It allows individual microbial colonies to grow and be isolated.
20What is colony morphology?
The visible appearance of microbial colonies growing on solid medium.
21What is a defined medium?
A medium with a precisely known chemical composition.
22What is another name for a defined medium?
Synthetic medium.
23What is a complex medium?
A medium whose exact chemical composition is not known.
24Why are yeast extract and protein digests used in complex media?
They contain mixtures of compounds whose exact composition is not fully known.
25What is an enriched medium?
A medium supplemented with a particular nutrient needed by a microorganism.
26What is a fastidious microorganism?
A microorganism that is difficult to grow and may require special nutrients.
27How does a defined medium differ from a complex medium?
A defined medium has a precisely known composition; a complex medium does not.
28Can a medium with many ingredients still be defined?
Yes, if the exact chemical composition and amounts are known.
29Can a medium with only a few ingredients be complex?
Yes, if one or more ingredients have an unknown chemical composition.
30What is the purpose of adding a special nutrient to an enriched medium?
To support the growth of a fastidious microorganism.