chapter 8 microbial metabolism Flashcards
catabolic reactions
that breakdown substances (nutrients) and
release energy
anabolic reactions
build up new substances
using the energy and building blocks obtained from the catabolic reactions
How is ATP produced
ADP + energy + P ATP
Phototroph
uses light for energy
Chemotroph
uses chemicals as the energy source
Autotroph
uses carbon dioxide (CO2) as the carbon source
Heterotroph
uses an organic compound as the carbon source
Chemoautotroph
use a chemical for energy but CO2 for carbon
Chemoheterotroph
use chemical for both energy and carbon
Photoheterotroph
light for energy but need an organic compound
for carbon
Photoautotroph
photosynthetic organisms (light for energy and
CO2 for carbon)
Organotrophs
energy from organic compounds
Lithotrophs
energy from inorganic compounds (unique to
the microbial world)
Oxygenic Photosynthesis
has oxygen as a
byproduct
Anoxygenic Photosynthesis
the byproduct is
not oxygen
What do enzymes do?
lower the activation energy needed for the
reaction to occur
what are enzymes made out of?
- proteins with cofactors
- protein part is called the apoenzyme
- protein with its cofactor is known as the
holoenzyme
coenzymes
Organic cofactors
what are electron carriers?
NAD+ and FAD
what is the reduced form of NAD+
NADH
(and the NADH
is now carrying the energy that was transferred)
Oxidation reactions
molecules losing
electrons
Reduction reactions
involve
molecules that gain electrons.
how do cells extract energy
by oxidizing
them and the electrons being removed come off as hydrogen
atoms
Substrate-level phosphorylation
occurs when
an enzyme directly transfers a phosphoryl group
to ADP (generally happens within the reaction
sequence)
Oxidative phosphorylation
involves reduced
coenzymes passing electrons to an electron
transport chain fueling the phosphorylation of
ADP (happens across a membrane)
Photophosphorylation
where light energy is
used to activate electrons (only occurs in
photosynthetic organisms)
how many reactions do glycolysis have
10
glycolysis
glucose is broken down into two
pyruvic acid molecules
what does glycolysis produce
- net gain is 2 ATP
- Also 2 NADH (reduced coenzymes) are produced
what happens in the intermediate step
pyruvic acid produced during glycolysis is
converted into acetyl-CoA
what gets produced in the intermediate step?
CO2 is released and an NADH is formed
why does the intermediate step happen twice?
- glycolysis resulted in 2 pyruvic acid
molecules
-2NADHs and 2 acetyl-CoAs are formed
what is the net result of the kreb cycle?
- 3NADH,
1FADH2 plus an ATP (at the substrate level) - happens twice
- 6NADH,
2FADH2 and 2ATP
what happens in the electron transport train?
This is where the energy stored in the reduced coenzymes (NADH &
FADH2) are used to produce variable amounts of ATP depending on
whether it is being driven aerobically or anaerobically
what are the results of the electron transport train?
NADH — 3 ATP
FADH2—- 2 ATP
how many ATPs are produced per glucose molecule after the electron transport train
38
per glucose molecule after glycolysis
2 ATP & 2NADH
per glucose molecule after intermediate step
2 NADH
per glucose molecule after kreb cycle
2ATP, 6NADH, & 2FADH2
whats the math with the ATPs after the electron transport train
-4 ATPs have been produced prior to the
electron transport chain
- along with 10 NADH
resulting in 30ATPs and 2 FADH2 resulting in 4 ATPs,
so for a prokaryote working aerobically 4+30+4=38
total ATP (per glucose molecule)
anaerobes
no oxygen
aerobes
oxygen
anaerobes produce _________ ATP
less
Fermentation is used because…
organisms that do not have or
cannot use respiratory chains can rely on
fermentation to produce energy
