Biogeochemical cycles

What are the three ways of generating ATP?

1. Substrate level phosphorylation

2. Oxidative phosphorylation

3. Photosynthetic phosphorylation

Does each step in the oxidative phosphorylation yield ATP?

No. only the steps that pump protons in the electron transport chain contribute.
ATP is produced only at ATP synthase, which uses the proton gradient.

What is the purpose of reversed electron transport?

• In some cases, electrons are directly going to oxygen

• In this process, NADH is not produced —> a problem for the synthesis of cell material

• This is solves by reversed electron transport. In this case, electrons flow against the gradient, which costs ATP.

What is the difference between oxygenic and anoxygenic photosynthesis? T

he difference is whether oxygen is produced during photosynthesis.

• Oxygenic photosynthesis: uses H2O as electron donor and produces O2 as a by product.
  » Happens in plants, algae and cyanobacteria.

• Anoxygenic photosynthesis uses H2S as an electron donor and does not produce oxygen.
  »Green and purple sulfur bacteria.

the unity of biochemistry and the classification of microbial metabolic types

1.       energiebron: chemo (van oxidatie chemische reacties) of photo (van licht)

2.       elektronendonor: litho (inorganische donor zoals H2S) of organo (organische donor (zoals C)

3.       koolstofbron: auto (C van CO2) of hetero (C is van organic compounds, want het kan niet zelf CO2 metaboliseren)

the valances of individual elements (high to low)

1. Nitrogen

2. Carbon

3. Sulfur

4. Iron + Mangenes