Catabolism 1 Chapter 11 Flashcards
Glycolysis
Glucose oxidized to pyruvic acid (pyruvate)
respiration
Krebs cycle, ETC, Chemiosmosis
Aerobic – O2 final e- acceptor
Anaerobic – O2 NOT final e- acceptor
fermentation
Different fermentation end-products
Organic compound = final e- acceptor
anaerobic respiration final electron acceptor examples
lactate fumarate carbon dioxide nitrate sulfate
fermentation final electron acceptor example
Pyruvate
aerobic respiration final electron acceptor
oxygen
Glycolysis - overview
Embden Meyerhof other name
Glycolysis
Occurs in cytoplasm (bacteria, eukayr, arachae)
2 Stages
What is glycolysis
Splitting of sugar (glucose)
6Carbons sugar split into 2 molecules of pyruvic acid (pyruvate) (3Carbons)
Electrons removed from glucose molecule
Two stages of glycolysis
Preparatory stage
Energy conserving stage
Glycolysis - intermediates
GGFFDG (Go get four fat Dog Guts) BPPPP ( by 4 p's) Glucose Glucose-6-phosphate Fructose-6-phosphate Fructose-1,6-bisphosphate Dihydroxyacetone phosphate and glyceraldehyde-3-phosphate* this is when splits in two 1,3-bisphosphoglycerate (2) 3-phosphoglycerate (2) 2-phosphoglycerate (2) Phosphoenolpyruvate (2) Pyruvate (2)
Glycolysis Preparatory Stage
Investment stage
Invest 2 ATP
No electron carriers involved
What happens in the glycolysis preparatory stage
Input: 1 glucose, 2 ATP
output: 2 glyceraldehyde-3-phosphate
Energize glucose
Keep sugar in cell
Glycolysis Energy-Conserving Stage
Payoff stage- produce 2 pyruvate
what happens during the energy conserving stage
Electron carriers reduced (NAD+ to NADH)
ATP produced by substrate-level phosphorylation
Input and output of the payoff energy conserving stage
2 ATP now 4 ATP
1 six carbon glucose now 2-three carbon pyruvate
2 NAD+ to NADH (reduced)
Dr. Kempf, what do I need to know about glycolysis for the exam??
Inputs, outputs, and net gains
Names and order of intermediates
Selected structures
Net gain of energy conserving stage glycolysis?
2 ATP
2 Pyruvate
2 NADH
Preparatory investment stage input output
input 2 ATP molecules
output 2 molecules of glyceraldehyde phosphate
First half of Glycolysis - intermediates
GGFFDG (Go get four fat Dog Guts) Glucose Glucose-6-phosphate Fructose-6-phosphate Fructose-1,6-bisphosphate Dihydroxyacetone phosphate & glyceraldehyde-3-phosphate* this is when splits in two
Second half of Glycolysis - intermediates
BPPPP ( by 4 p's) 1,3-bisphosphoglycerate (2) 3-phosphoglycerate (2) 2-phosphoglycerate (2) Phosphoenolpyruvate (2) Pyruvate (2)
Alternative to glycolysis
Entner-Doudoroff pathway
Pentose-Phosphate Shunt (PPS)
Entner-Doudoroff pathway
Pseudomonas aeruginosa, and other soil bacteria
Glucose oxidized to pyruvate
Different enzymes and intermediates than glycolysis
Input and Output of Entner-Doudoroff pathway
Net yield input 1 glucose:
2 Pyruvate 1 ATP, 1 NADPH, 1 NADH
what does not use Entner Doudoroff pathway
not in gram positive
Entner Doudoroff pathway
Different enzymes and intermediates than glycolysis
2-keto-3-deoxy-6-phosphogluconate (KDPG)
Cleaved to pyruvate and glyceraldehyde-3-phosphate
Pentose-Phosphate Shunt (PPS)
Used by all organisms
Break down 5C sugars and glucose
Pentose-Phosphate Shunt (PPS) Produce intermediates for:
Glycolysis
Glucose biosynthesis
Nucleic acids biosynthesis
Some amino acid biosynthesis
Pentose-Phosphate Shunt (PPS) net gains
Net yield: 2 NADPH, 1 ATP
Where does pyruvic acid (pyruvate) go?
respiration
fermentation
Electron transport chain & Chemiosmosis
ATP-generating process
Electron carriers oxidized
Krebs cycle comes when
After glycolysis
Another name for Krebs Cycle
Tricarboxylic acid cycle (TCA)
what happens during Krebs cycle
pyruvate from glycolysis is oxidized to CO2
Electron carriers reduced
ATP from substrate level phosphorylation
What are the electrons carriers for Krebs
NADH FADH2
Output for Krebs Cycle
input 2 pyruvate
output 3 things: 6 CO2, 2 ATP, 8 NADH 2 FADH2
Output for Krebs Cycle
Output: 8 NADH, 2 FADH2, 6 CO2, 2 ATP
Krebs occurs where
Occurs in:
Cytoplasm = Bacteria and Archaea
Matrix = Eukaryotes
How many turns does the Krebs cycle take
- To use up both pyruvates
input for Krebs
Input: 2 Pyruvate (as acetyl-CoA), 8 NAD+, 2 FAD
How many steps in Krebs cycle
6 steps
order of krebs steps
see slide 36
Decarboxylation Attach Acetyl group (2C) to oxaloacetate Decarboxylation Decarboxylation Substrate-level phosphorylation Regenerate oxaloacetate
What happens in decarboxylation
- (3C 2C + CO2)
- (6C 5C + CO2)
- (5C 4C + CO2)
each time NAD+ is reduced to NADH
What happens with the acetyl group attached
makes 2 carbon acetyl group and 4 carbon oxaloacetate a 6 carbon chain
what is Substrate-level phosphorylation
formation of ATP from ADP and a phosphorylated intermediate
what is difference between Substrate-level phosphorylation and oxidative phosporlyation
Both processes produce ATP from ADP and Pi substrate level phosphorylation occurs when enzymes remove a “high-energy” phosphate from a substrate and directly transfer it to ADP,
oxidative phosphorylation is based on electrons moving through and ETC and production of a proton-motive force that drives ATP
Last step of Krebs
Regenerate oxaloacetate (4C)
Reduce electron carriers (NAD+ & FAD)
so they can be used again
Krebs Cycle input summary
2 Pyruvate (as acetyl-CoA), 8 NAD+, 2 FAD
Krebs cycle output summary
8 NADH, 2 FADH2, 6 CO2, 2 ATP
2 steps of Krebs cycle
Pyruvate oxidation
Citric acid cycle
INput of Pyruvate oxidation (1 glucose)
2 pyruvate 2 NAD+
INput from Citric acid cycle
2 Acetyl CoA, 6 NAD+, 2 FAD 2 ADP
Output of Pyruvate oxidation
2 Acetyl CoA 2 CO2 2 NADH
output for Citric acid cycle
6 CO2 8 NADH 2 FADH2 2 ATP by SLP
Total output: from Krebs Cycle
6 CO2, 8 NADH, 2 FADH2, 2 ATP
Oxaloacetate =
oxaloacetic acid
What comes after the Krebs cycle in respiration
Electron transport chain