Chapter 8- Respiration Flashcards
What do green plants, some protoctists and some prokaryotes use light for
They use it as a source of energy to drive the formation of ATP and redNADP (P is used to indicated that it is used for photosynthesis) that provide energy to fix carbon dioxide and form complex carbon compounds. The organisms that first used light as a source of energy were most likely similar to the cyanobacteria that are found today in stromatolites.
What is another source of energy that organisms use and give me an example
They use chemicals. For example, several individuals of a species use hydrogen gas as a source of energy. These hydrogen-oxidising bacteria have hydrogenase enzymes In the cell membrane and the cytoplasm that breakdown hydrogen to form electrons and protons. In the membranes, electrons pass to electron carriers to provide energy for proton pumping and ATP synthesis. The electrons are used to reduce NADP. So, indirectly hydrogenase provide ATP and reduced NADP to drive carbon fixation in the Calvin Cycle in these bacteria. Many other bacteria and archaens use other sources of chemical energy in the same way.
What do autotrophic organisms affect carbon
It fixes carbon as complex organic molecules which they can use as a source of energy and store for use in the dark or when the conditions are unfavourable.
Inorganic molecules of carbo would be carbon dioxide for example and autotrophic molecules such as plants would convert it to glucose (which is an organic molecule).
They can also use these organic molecules to build cellular structures(e.g cellulose made from beta glucose).
Why do plants need respiration
They cannot rely on photosynthesis as an energy source all the time and so need the energy that is stored in molecules, such as carbohydrates, proteins and fats, to be released and made available for cells. This is achieved by the chemical process of respiration.
How do heterotrophs gain their supply of energy
These organisms cannot fix carbon dioxide rely directly or indirectly on organic compounds made by autotrophs. They eat plants or other organisms that ultimately derived their energy from autotrophs.
Relationship between respiration and photosynthesis
These are complementary. Green plants do both during the day. However, they cannot photosynthesis during the night due to the lack of light.
How does the energy flow (interrelationships between photosynthesis and respiration)
Photosynthesis
This is where light-dependent stage occurs which produces ATP and RedNADP. This enables the light-independent stage to occur
This whole process produces oxygen which is a reactant in aerobic respiration. Respiration produces carbon dioxide and water which are reactants in photosynthesis.
Respiration gives off heat and also ATP.
Why is respiration necessary
Plants, animals and microorganisms respire to transfer energy from carbon compounds to ATP, the ‘energy currency’ of cells.
