lecture 1 Flashcards
what is the definition of bioenergetics?
study of the transformation of energy in living organisms
what is the definition of metabolism?
sum of all chemical reactions in the body
what are the types of metabolic reactions?
catabolic and anabolic
what is a catabolic reaction?
when we eat, breaks down food we digest – releases energy – breakdown or degradation of molecules
what is an anabolic reaction?
synthesis of new molecules – energy released from anabolic reactions can be used to build new molecules – can build muscles, become strong, cancer growth – grow and divide which happens due to the energy released
what are catabolic pathways?
proteolysis, lipolysis – fat breakdown, glycolysis – glucose breakdown, glycogenolysis – glycogen breakdown
what are anabolic pathways?
protein synthesis, lipogenesis - building of fatty acids, gluconeogenesis – building of glucose, glycogenesis – building of glycogen
how do pathways occur?
continually but not simultaneously
how are pathways regulated?
- Substrate supply – food and other compounds
- Hormonal control – switch on or turn off pathways and alter enzyme activity
- Allosteric control – speed or slow enzyme activity – fast acting regulator of these pathways
what is ATP?
Adenosine Triphosphate
what does ATP do in our body?
- fuels us - energy currency of the cell
- food we consume is digested and used to generate ATP
- what we fuel all our metabolic reactions
what is ADP?
Adenosine Diphosphate - 2 phosphate groups
what is AMP?
Adenosine monophosphate - one phosphate group
how is ATP generated?
metabolic reactions
what do enzymes do?
- speed up reactions so that we don’t die, lowers activation energy
- they are specific - they can only catalyse one specific metabolic reaction – it has an active binding site and can only bind to one specific site
How do enzymes know if they can fit and form an enzyme substrate complex?
lock and key principle and induced fit principle
what is the lock and key principle?
binding site has complementary shape to substrate(s)
what is the induced fit principle?
contact between part of the binding site and the substrate induces a change in shape of the active site to bind to the substrate
what is allosteric control?
where a molecule other than the molecules and substrate itself can bind to the enzyme – can change the shape of the enzyme – energy status of the cell
how is enzyme activity affected by its local environment in the cell?
substrate concentration, pH, enzyme concentration and temp
what are anaerobic fuel sources?
ATP, phosphocreatine, glycolysis
what are aerobic fuel sources?
glycolysis, carbohydrate oxidation, fat oxidation, protein breakdown
