2016 PE Flashcards
What is the mode of action of an enzyme?
Enzymes are highly specific to the reaction they catalyse, reactions occur due to their ability to reduce activation energy and speed up biological processes.
- Lock and key model: activation centre is in the lock and the substrate is the key. It is a perfect fit
- Induced fit model: enzyme undergoes a conformational change before binding with the substrat
How is enzyme activity regulated?
Regulatory molecules: enzyme activity turned up or down by activator (up) and inhibitor (down) molecules that bind specifically to the enzyme
Cofactors: many enzyme are only active when bound to non-protein helper molecules (cofactors)
Compartmentalisation: storing enzymes in specific compartments can keep them from doing damage or provide the right conditions for activity.
How is lactic acid produced in a silage pit?
Silage fermentation much be anaerobic so that lactic acid bacteria grow and stabilise the silage. During the fermentation phase lactic acid bacteria grow and start producing lactic acid
How is lactic acid produced in exercising muscles?
It occurs when there is insufficient oxygen in the muscles (anaerobic) which results in the release of energy via anaerobic cellular respiration. Therefore the waste product is lactic acid as there is an incomplete breakdown of glucose and and instead of the usual by products of H2O and CO2, lactic acid is produced instead because there is insufficient oxygen to oxidise the produced lactic acid
Why does ketosis occur at parturition of an animal with a high level of milk production?
There is an increase demand for glucose. This causes a blood level and body tissue deficiency of glucose because the animals demands are so high. The glucose is prioritised for developing calves and milk production. The demands get so high that the liver must start manufacturing the required glucose from fat reserves which produces undesirable ketones. These ketones need glucose in the liver to convert them to usable energy. But if the glucose levels are too low the ketones build up in the blood which causes a lot of issues and effects the brain.
Where does a carnivore get its glucose from?
Sugars are a simple carbohydrate which provide the tissues with energy or is stored as glycogen or body fat. Glucose is consumed as proteins and fats. Giving us amino acids and glycerol which the liver manufactures these two into glucose.
