nutrition Flashcards
What is nutrition to organisms?
It is the way an organism gets its food
How does bacteria get its food?
It gets it in four different ways.
How are the four methods in which bacteria gets their food divided?
The four methods are grouped in pairs, under the headings of autotrophic and heterotrophic .
Define autotrophic
It means an organism makes its own food
What sources of energy are needed for an organism to make its own food?
sunlight (photosynthesis) or energy released from chemical reactions (chemosynthesis)
What do photosynthetic bacteria often have?
They often have chlorophyll on membranes within the cell (i.e. not in the chloroplasts) and use the same type of light as plants.
How do some photosynthetic bacteria differ from plants?
They can have different pigments than plants and use mostly red light. .
Some do not use water, but live on hydrogen sulfide gas. These are called purple sulfur bacteria.
Some photosynthetic bacteria do not use water but live on hydrogen sulfide gas. What is this bacteria known as?
Purple sulfur bacteria
Define chemosynthesis
It is the production of food using energy released from chemical reactions
What do chemosynthetic bacteria use to make food?
They make food using energy from reactions involving ammonia, sulfur compounds and iron compounds.
Give an example of chemosynthetic bacteria
nitrifying bacteria in the nitrogen cycle
Define heterotrophic
It means an organism takes in food made by other organisms
Define saprophytes
They are organisms that take in food from dead organic matter
What are bacteria mostly in terms of the four methods of obtaining their food?
Most bacteria are heterotrophic
What do heterotrophic bacteria do in their environment?
They secrete enzymes into their environment and absorb the digested food
