Biology Topic 5 : Microorganisms in mineral cycling

What is the tole of micoorganisms in ecosystems?

They recycle chemical elements like nitrogen and phosphorus

What are two key groups involved in mineral cycling?

Saprobionts and mycorrhizae

What are saprobionts?

Microorganisms (bacteria/fungi) that decompose dead and waste organic matter

How do saprobionts digest material?

They secrete enzymes and carry out extracellular digestion

What happens after extracellular digestion?

saprobionts absorb nutrients, but leave mineral ions in the soil

What mineral ions do sapprobions release?

Nitrates and phosphates

What is the role of saprobions in the nitrogen cycle?

They carry out ammonification (organic nitrogen to ammonia)

What are mycorrhizae?

Symbiotic relationship between fungi and plant roots

What do fungal hyphae (threat like structures that make up fungi) do?

Increase the surface area of plant roots

What does increased surface provided by hyphae area help with?

Better absorption of water and mineral ions

what do fungi recive from the plant?

Carbon compounds such as glucose

What is the role of saprobionts?

Decompose organic matter and release inorganic ions into soil

What is the role of nitrogen fixing bactera?

Converts nitrogen gas into ammonia

What is the role of nitrifying bacteria ?

Convert ammonium into nitrites and thn nitrites into nitrates

What is the role of denitrifying bacteria?

Convert nitrates into nitrogen gas in anaerobic conditions

What is the role of mycorrhizal fungi?

Help plants absorb water and mineral ions more efficiently