topic 5 - organotrophy Flashcards
(37 cards)
what is aerobic respiration
combustion reaction
glucose is “burned” in O2 to produce CO2, water, with the release of heat
series of coupled redox reactions that release the free energy of glucose and transfers energy to other molecules (NADH, FADH2, ATP) and products
what is the difference between oxidation and reduction
oxidation = loss/partial loss of e-
reduction = gain/partial gain of e-
what happens during coupled redox reactions
non polar covalent bonds in the reactants are broken
polar covalent bonds in the products are formed
what happens during the coupled reactions in aerobic resp
bonding e- shared equally between the C atoms in glucose have moved further away from the C nuclei in CO2
- glucose is oxidised as it forms CO2
bonding e- shared equally between the O atoms in O2 have moved closer to the O nuclei in water
- O2 is reduced as it forms water
what is the importance of the nicotinamide ring in NAD+
important in gaining / losing e-
molecule gains 2 e- and 1 proton through reduction to NADH
what is the importance of flavin ring in FAD+
helps it gain 2 e- and 2 protons
what is reduction potential
production of NADH/FADH2
what is a reduced e- carrier
e- transport molecules that move e- from one reaction to another
transports energy in the form of high energy e-
where does glycolysis occur
present in all - archaea, bacteria, and eukarya
occurs in the cytosol
what is glycolysis
partial oxidation of glucose
occurs through 10 connected reactions (product becomes substrate)
each reaction is catalysed by an enzyme
what are the energy requiring reactions and energy releasing reactions in glycolysis
energy requiring
- glucose (6C) —> 2 G3P (3C)
- uses 2 ATP
energy releasing
- 2 G3P (3C) —> 2 pyruvate (3C) + 2 H2O
- releases 2 NADH and 4 ATP
what is the net ATP of glycolysis
2 ATP
(2 used, 4 created)
how are e- carriers reduced in glycolysis
proton and 2 e- from G3P are transferred to NAD+ to make NADH
what is substrate level phosphorylation
have:
- phosphorylated organic/reactant molecule
- ADP
- enzyme (not ATP synthase)
GENERATES ATP (how ATP is made in glycolysis)
2 molecules bind together in an enzyme active site and catalyse the transfer of P from a organic molecule of ADP to make ATP
what happens after glycolysis
not much ATP made - lot of energy still trapped in pyruvate
cell needs to remove pyruvate - don’t want final product build up in the cell
cell needs to restore NAD+ - need a way to oxidise the NADH made in glycolysis
what is fermentation
anaerobic reduction of pyruvate
when and where does fermentation occur
if O2 is limiting - pyruvate enters a fermentation pathway
occurs in eukaryotic and prokaryotic
occurs in cytosol
what is the main goal of fermentation
to oxidise NADH to NAD+
what is involved in lactate fermentation
reduce pyruvate to lactate (gains H+ atoms)
coupled to oxidation of NADH to NAD+
allows for glycolysis to continue (more NAD+ to support another round)
what is involved in alcoholic fermentation
pyrvuate decarboxylated - CO2 molecule removed
acetaldehyde reduced to ethyl alcohol (H atoms added)
coupled to oxidation of NADH to regenerate NAD+
products = ethanol and CO2
where is the inner membrane compartment / space (IMS) located
space between inner and outer membranes
what occurs in the mito matrix (inside both membranes)
pyruvate oxidation and citric acid cycle
what happens on the inner mito membrane
electron transfer
ATP synthesis
how does pyruvate get into the mito matrix
facilitated diffusion to get across outer mito membrane
high concen of pyruvate in matrix
secondary active transport (symport) with H+ moving from high to low to pull pyruvate across inner mito membrane
