L4 Metabolism Of Organic Molecules Flashcards
What method is used by most life
Chemoheterotrophy
What 2 things are carbon comounds used for in chemoheterotrophy
Generating energy and the biosynthesis of macromolecules
What are some potential carbon sources in nature
Proteins
Lipids
Carbohydrates
Aromatics
Why is wood hard to breakdown
Its a mix of many different C sources
Why are amino acids not often used for biosynthesis
The cost of breaking down amino acids releases little energy, onlt need to be broken down if nitrogen is needed
How many main routes in microbes are there to breakdown glucose
3
Glycolysis (EMP), Enter-doudoroff (ED), and pentose phosphate pathway (PPP)
3 energy generating metabolic processes
Aerobic respiration
Anaerobic respiration
Fermentation
What is broken down in fermentation and when does it occur
Carbohydrates broken down in absence of oxygen
What kind of electron acceptors are used in fermentation
Organic e.g. NAD+
What is released in fermentation
Small organic molecules e.g. Ethanol
Nor carbon dioxide and water
What happens in aerobic respiration and when does it occur
What electron acceptor is used
What is produced
Breakdown of carbohydrates in prescence of oxygen
Oxygen
Carbon dioxide and water
Why can oxygen and FAD+ be bad for anaerobes
They generate reactive oxygen species (ROS)
Hydroxides or can react to form hydroxyl ions damaging DNA, RNA and membranes
Anaerobic microbes cannot detoxify ROS
How many ATP’s are produced in aerobic respiration per one molecule of glucose
38
How many ATP’s are produced in bacteria under artobic respiration
~20
What are H+ and NADH used for in bacteria during aerobic respiraton that effects ATP output
H+ to maintain memebrane proton potential
NADH is a co-factor in some enzymes
What is the glyoxylate bypass
When is it used
When the full TCA cycle is not used
The step releasing carbon dioxide is skipped when in low carbon environemt or when carbon is needed more for respiration and byosynthesis
What is disimilation
Successive reduction
What is dissimilation of nitrogen and sulfur important for
Successive reduction of nitrogen and sulfur is vital in the N and S cycles
What is fumurate (trimethylamine oxide) reduced to and how can you tell if this is present
Trimethylamine
Fishy smell
Name a metal often involved in dissimilatory metal reduction
What can be produced
Fe3+
Metal precipitation
What completes the glucose-pyruvate catabolism pathway
Fermentation
What are the conditions in the bottom of the winogradsky column
Anaerobic
What are 2 drawbacks of fermentation
Lower energy yield
Potential organic energy excreted
What are 2 possible reasons for fermenting
Suitable electron acceptors not available
Excreted producs can inhibit other organisms
