Metabolic diversity

When defining metabolic types, what are the 2 main factors?

the energy and the carbon source

When an organism is called chemotroph, what does this translate?

uses preformed molecules as an energy source

When an organism is called phototroph, what does this translate?

uses sunlight as an energy source

When an organism is called heterotroph, what does this translate?

organic compounds as carbon source

When an organism is called autotroph, what does this translate?

inorganic compounds as a carbon source

What would be the energy and carbon sources of a photoheterotroph? Name an ex. of species

energy from sunlight, carbon from organic compound

purple and green non-sulphur bacteria

What is a third factor in defining a metabolic type? What are the 2 options?

source of electrons

organic source or inorganic source

Name an example of a photoorganoautotroph

aren’t any

Describe catabolism

breaking down molecules

Describe anabolism

synthesis of molecules

Through anabolism, what are the 3 possible pathways of products produced?

• long-term energy storage

• biosynthesis of ATP

• biosynthesis of carbon, nitrogen, water

What is a product of catabolism?

ATP

What are different types of electron donors?

• Chemoorganotrophy: organic molecules

• Chemolithotrophy: inorganic molecules

• Phototrophy: use light energy to reduce compounds, 

    then use these as electron donor

What are 2 types of electron acceptors?

• Respiration: inorganic or organic molecules 

• Fermentation: organic molecules

In what type of potential gradient does electron transfer occur in prokaryotes?

from low to high potential

Under what form is energy conserved in prokaryotes? What is it used for?

transmembrane PME

ATP synthesis via the ATP synthase

slide 15

Metabolism produces which 2 sources of energy?

- Reducing power (NADH, NADPH, FADH2)

- ATP

How does electron transfer drive ATP synthesis?

Energy generated during electron transfer generates a proton gradient that drives ATP synthesis

Basically what is metabolism’s final aim?

to get reducing power and ATP

What types of preformed organic compounds can be used by chemoorganotrophs as a source of electrons?

• Carbohydrates

• Lipids

• Peptides

• Aromatic compounds

What are 2 key metabolites produced by chemoorganotrophs?

• Acetyl-CoA

• Pyruvate

What are pathways that lead to the formation of metabolites and energetic currencies by chemoorganotrophy? What are the metabolites and energetic currencies?

glycolysis, entner-doudoroff and pentose phosphate pathway

ATP, NADH+H+ and FADH2

What type of respiration can chemoorganotrophs do when in presence of oxygen? The 2 types in absence of oxygen?

aerobic respiration

anaerobic respiration and fermentation

How does oxygenic respiration in chemoorganotrophic prokaryotes work?

slide 22

How does anaerobic respiration in chemoorganotrophic prokaryotes work?

What differentiates anaerobic respiration and fermentation?

When does fermentation occur in chemoorganotrophic prokaryotes?