Intermediary Metabolism Flashcards
What is intermediary metabolism?
Reactions occuring between:
- Absorption of feedstuff
- Excretion of end products
- Proteins
- Polysaccharides
- Fats
- Amino acids
- Monosaccharides
- Fatty acids
- NAD+
- NADH
Oxidative phosphorylation
ADP → ATP
Oxidative processes occur in the…
Mitochondria
What are the byproducts of biological oxidation
- Heat
- CO2
- H2O
Catabolism
Anabolism
Metabolism
- Chemical reactions occurring in living cells
- Allows cells to reproduce and grow
Metabolism is split into which two categories?
- Anabolism
- Catabolism
Catabolism
- Yields energy as ATP
- Breakdown of food in biological oxidation
Anabolism
- Uses energy
- Constructs components of cells
- Protein + nucleic acid production
Rate limiting step
- Slowest reaction in a pathway
- Determines the rate for the pathway
Reactions which involve both anabolism and catabolism
Amphibolic reactions
Give the three stages of energy extraction
- Formation of smaller molecules
- Formation of simple units
- Citric acid cycle (Resp. chain + Oxidative phosphorylation)
Formation of smaller molecules
Break down of:
- Fats
- Polysaccharides
- Proteins
Formation of simple units
- Primarily Acetyl CoA
- Fatty acids, glucose and amino acids are broken down into a common intermediate
- Glycolysis
Citric acid cycle
- NADH + H+ production
- FADH2 production
- Oxidisation of acetyl-CoA
Similarities and differences of biological oxidisation and combustions
- Similarity:
- End products are CO2 + H2O
- Difference:
- Biological oxidation: 40% of energy is stored as ATP
- Combustion: Heat + light produced
Energy produced
2872 kJ/mol
Energy produced
1102 kJ/mol
Energy produced
9800 kJ/mol
Energy produced
3948 kJ/mol
Give the two methods of producing ATP from different substrates
- Oxidative phosphorylation
- Substrate-level phosphorylation
Oxidative phosphorylation
Process of forming ATP by a proton motive force
Substrate-level phosphorylation
- Direct phosphorylation of ADP from phosphorylated intermediates
- Seen during glycolysis/GTP-forming step in citric acid cycle
Metabolic energy is stored in the…
High energy bonds
Give a ‘high energy’ bond
Phosphoanhydride bond
What gives ‘high energy’ bonds their energy?
- A large negative free energy change (ΔG) of hydrolysis
- High group transfer potential
AMP function
- Energy sensor
- Regulator of metabolism
- Stimulates metabolic pathways → ATP
Use of phosphocreatine/ creatine phosphate
- Used in nerve and muscle cells
- Storage of ~P bonds
What reaction does creatine kinase catalyse?
Phosphocreatine + ADP ↔ ATP + creatine
Where does creatine synthesis occur?
- Kidney (1st reaction)
- Liver (2nd reaction)
What regulates creatine synthesis?
Arg-Gly transamidinase
Name the high energy bond found between a carboxylic acid and a thiol group of coenzyme A
Thioester bond
Acetyl ~ CoA
The spontaneity of thioester cleavage is essential to the role of coenzyme A as an…
Acyl group carrier
Give the reaction for thioester bond formation
Free energy change of: Phosphocreatine
-43.1 kJ/mol
Free energy change of: Thioester bonds
-31.48 kJ/mol
Free energy change of: ATP → ADP
-30.6 kJ/mol
Respiratory chain
- H2O production in biological oxidation
- By electron transport
