L2: Bioenergetic Metabolism 1 Flashcards
Buildng blocks of life
C H O Ph N
Define metabolism
chemical process that occurs in living things to maintain life
Anabolism
energy added, G>0, building
Catabolism
releasing energy, destroys, G<0
Gibbs free energy
thermodynamic potenital of system (enthalpy +entropy)
How does ATP store energy
phosphanhydride bonds from Redox
3 ways to release energy from ATP
- ATP + H20 = ADP + Pi + zap (first bond)
- ATP + H20 = AMP + ppi (second bond, this includes the already broken one)
- ATP + organic = ADP + organic - P + zap
- Instead of water use an organic molecule
What are reducing equivalents
electrons
Oxidation
- loss of electrons
- things that have oxidised have:
1. 2e-
2. electron carrier
3. NAD+
4. FAD
2e-, LEO
Reduction
gain of electrons
* Things that have been reduced have
1. another H in main molecule because H attached meas it has e-
Reduction Potential. What are the trends
capacity to accept electrons, defined by e- not molecules
Eo
do not factor
More Eo = reduction
Less Eo = oxidation
Redox tower trends
- more down = more energy
- Eo + G have different signs
- in tower all reduction, oxidiser switches signs
What are terminal electrons acceptors (4)
- final molecules recieving e-
- must have higher reduction potential then the molecule
- no energy added
- cannot be e- carrier
Relationship between FADH and NADH
FADH is weaker = lower
preffered cus it is lower can be given e-
What can animals/protists do?
take e- from organic compound (diet, photosynthesis) and give them to oxygen (TEA)
What are the goals of catabolism
- Generate energy for cellular processes by REDOX, oxidative phosphorylation and substrate level phosophorylation
- Generate energy for biosynthetic reactions
What are the majot forms of catabolism
- Fermentation: central catabolic pathway + fermentatin pathway (SLP)
- Respiration: central catabolic pathway + TCA cycle + etc
What is the goal of central catabolic pathways
glucose => pyruvate
Name the central catabolic pathways
- EMP
- ED
- PPS
EMP
2: ATP, NADH, Pyruvate
Key enzyme: phosphofructokinase
ED
1: ATP, NADH, NADPH
2: pyruvate
key enzyme: 6-phosphogluconate
dehydratase, KDPG aldolase
PPS
1: ATP
2: NADH, pyruvate
key enzyme: 6-phosphogluconate
dehydrogenase
hydro = peepee
Fermentation occurs when…
e- have nowhere to go
Describe the process of fermentation
- reduced e carriers need to give away e- because they are not TEA
- meaning the e- will be given to pyruvate and it’s deritivies
- resulting in no net change in oxidation because e- was given from glucose carbon back to carbon
- the e- is regenerated
- waste products because the products do not provide the cell with energy
What happens if TEA available
- Pyruvate => to ACoa => producing 2 NADH
- ACoa combined with oxaloacetate to enter TCA
What happens in TCA cycle
- 1 glucose => 2 spins
- provides even more reducing power for e-
What are the steps in e- transport chain. 3 key phases
all the cycles have created a lot of reducing power and e- carriers must be generated
1. Initial substrate oxidoreductase (dehydrogenase): recieves e- from carrier, releases H+, gives them to Quinone
2. Quinone: has many types, is reduced to quinol and gives to terminal oxidase
3. Terminal oxidase: gives to TEA, releases more H+
4. The e- gradient powers ATP synthase anf makes a lot og aTP
What is a great example of Metabolic versatility
non-sulfur bacteria that can eat up so many toxins called R. palustris
