KA1 Flashcards
(25 cards)
metabolism definition
cell metabolism refers to all chemical reactions that take place inside living cells
what are metabolic pathways
a series of integrated and controlled chemical reactions which are controlled by different enzymes
3 steps of pathways
reversible, irreversible and alternative
irreversible reactions
ensures a continuous influx of a metabolite and can drive forward metabolic pathways
alternative routes
allows steps in the pathway to be by-passed. this is useful when metabolite is in plentiful supply
membrane
allows transport in and between cells. It forms compartments and surfaces for metabolic pathways to allow for high concentration substrates and reaction rates
catabolic reaction
breakdown of a complex molecule into simple molecule releasing energy. Example is protein to amino acid
anabolic reaction
biosynthesis(build up) of a simple molecule into a complex molecule, requiring energy. Example is amino acids to protein.
temp/pH enzyme action description
as temp/pH increases enzyme acitivity also increase until reached its optimum. As temp/pH increases enzyme activity decreases
temp/pH enzyme action explanation
when enzyme reaches optimum, it becomes denatured meaning active site changes shape, no longer binding to substrate..
effect of substrate concentration
increasing substrate concentration also increases rate of reaction until certain point
induced fit
ensures active site comes in close contact with substrate increasing chance of reaction taking place
channel [pore] proteins
allows specific molecules and ions to pass through the membrane by passive transport
carrier [pump] proteins
binds to specific molecules and ions temporarily enabling them to pass through the membrane by active transport
enzyme functions in membrane protein
some proteins in membrane catalyse specific reaction
structural support protein function
some proteins help maintain shape of cell
what are enzymes and importance of them?
they have active site where a substrate binds to and catalyses a reaction. They’re required to initially break bonds for a reaction to take place. Their energy is required to starts a chemical reaction known as ‘activation energy’
substrates have..
high infinity for active site
products have..
low infinity and leave active site
name 3 enzyme inhibitors
competitive, non-competitive and feedback/end-product
competitive inhibition
when a molecule similar to the substrate binds to enzymes active site, preventing binding of actual substrate. Can be reversed by increasing substrate concentration.
non-competitive inhibition
when the substrate doesn’t bind to enzymes active site but binds to a different part of the enzyme. This decreases reaction rate and changes active site shape. Can not be reversed by increasing substrate concentration
end product inhibition
when end product of a metabolic pathway binds o enzyme at the start of a metabolic pathway
what does end product inhibition stop?
it stops the metabolic pathway and prevents further synthesis of the end product until the end product concentration decreases. The higher the concentration of the end product the quicker the metabolic pathway stops.
