Topic 4.4 Flashcards
What do autotrophs absorb
Carbon dioxide
What is the mean CO2 concentration in the atmosphere?
0.0039%
Where in the world is the carbon concentration lower?
In regions below the equator where there is an abundance of plants, therefore more absorption of CO2 through photosynthesis
In what two ways is CO2 soluble in water?
It can dissolve as a gas, or combine to form carbonic acid (H2CO3)
What do dissolved CO2 and ions absorbed by aquatic autotrophs make?
carbon compounds
How is the internal concentration of CO2 in autotrophs increased?
Because they use carbon dioxide in the production of carbon compounds. This increases the concentration of CO2 in autotrophs and creates a concentration gradient between cells in autotrophs and surrounding air and water. Therefore, CO2 diffuses from air and water into autotrophs
CO2 is a waste product of what in autotrophs, saprotrophs and animal cells?
aerobic cell respiration
Where does CO2 diffuse from and into when plants perform cell respiration
from the plant cells into surrounding air and water
What three types of anaerobic prokaryotes are involved in methanogenesis?
- bacteria that convert organic matter into a mixture of organic acids, alcohol, hydrogen and CO2.
- bacteria that use the organic acids and alcohol to produce acetate, CO2 and hydrogen
- ARCHAEANS that produce methane from CO2, hydrogen and acetate
In what kind of environment do archaeans carry out methanogenesis?
Anaerobic
- mud along shores and in beds of lakes
- Swamps, wetlands
- Landfill site
How long does methane stay in the atmosphere?
12 years
How does methane oxidise?
In the stratosphere by monatomic oxygen or hydroxyl radicals. It oxidises into water and carbon dioxide.
How does peat form?
When water is unable to drain out of soil and the environment becomes anaerobic and waterlogged. Saprotrophs don’t get enough oxygen and therefore organic matter isn’t fully decomposed. Thus peat is formed.
What is coal formed from?
Partially decomposed matter (peat) from past geological eras that have been compressed and heated over time to form coal.
What remains stable and unchanged over long periods of time?
Carbon
