Introduction to Metabolism Flashcards
Define metabolism
Means by which organisms extract energy from their environment and use it to synthesize large molecules
Give 3 examples of disorders that involve changes in the balance of metabolic activities?
- Diabetes
- Obesity
- Vitamin deficiencies
how much oxygen does a resting human consume a minute?
250ml
1.25 litres/ 5 minutes
What is the oxygen used for in the body?
To oxidize substrates and produce energy for the body’s needs
Define Anabolism
Process by which large molecules are built from smaller ones
It requires an energy input
Define Catabolism
Breakdown of large molecules to smaller ones
Releases energy
What is the energy produced by catabolism used for?
To drive anabolism and other energy requiring processes
When can a reaction occur spontaneously?
If the free energy change is negative
What does the reaction rate depend on?
The energy hump that must be climbed for the reaction to occur. This is called the free energy of activation
It is unrelated to delta G
What is phosphorylation?
Adding a phosphate group to a molecule e.g. conversion of ADP to ATP
How much energy is released when ATP is hydrolysed?
approz 7-12 kcal/mol
How much ATP does the body consume within 24 hours?
40kg
What is ATP needed for?
- Body movement
- Cellular movements
- Active transport
- Synthesis of large molecules
Give 3 ways that metabolism is regulated
- Changes in amounts of substrates and products of pathways
- Changes in amounts of key enzymes
- Changes in activity of key enzymes
• Allosteric changes
• Effects of substrate and downstream products on enzyme activity
• Covalent modification of enzymes
What is delta G?
Free energy change
