Metabolic Pathways Unit 1 Flashcards
What name is given to the thousands of biochemical reactions that occur in living cells ?
Metabolism
The quantity of energy consumed by an organism per unit time is measure of what rate ?
Metabolic rate
Name two types of metabolic pathways involves the breakdown of complex molecules to simpler ones
Anabolic and Catabolic pathways
Which type of metabolic pathway involves the breakdown of complex molecules to simpler ones ?
Catabolic
Which type of metabolic pathway involves the build up of complex molecules to simpler ones ?
Anabolic
Which type of metabolic pathway releases energy as it is breaking complex molecules down ?
Catabolic
Which type of metabolic pathway requires energy as it builds up small molecules to complex molecules ?
Anabolic
In a metabolic pathway, what do two opposing arrows means ?
The reaction is reversible
Metabolic reactions sometimes have places where steps can be bypassed, what are these pathways known as ?
Alternative routes
Give three properties of a catalyst
- Lowers the activation energy
- Remains unchanged at the end
- It increases the rate of reaction
What name is given to biological catalysts ?
Enzymes
What state is reached when two reactants have bonds broken and they are in a position that is unstable and ready to form a product ?
Translation state
What substance are enzymes made of ?
Protein
What name is given to the area on an enzyme that meets with the substrate ?
Active site
What determines the shape of the active site ?
The sequence of amino acids in the polypeptide that makes up the enzymes molecule
Give the word that is used to describe the fact that one enzyme fits one substrate
Specific
Give the term that is used to describe the fact that the active site has a strong attraction for the substrate
High affinity
Once the enzyme has broken the substrate down/ built it up and formed the product, how is the attraction for the active site described ?
Low affinity
In order for the enzyme’s active site to fit the substrate more closely, the shape of the active site and enzyme changes slightly. What is this called ?
Induced fit
The shape of the active site determined the what of reactants ?
Orientation
In an enzyme controlled reaction, the reaction rate will increase as the substrate concentration increases up until a certain point. After that, the rate of reaction does not increase, why is this ?
Because all of the active site on the enzyme are occupied
What can be done to increased the rate of an enzyme controlled reaction once all of the active sites on the enzyme are occupied and substrate has already been increased ?
Add more of the enzyme to the reaction
In a metabolic pathway, if there if a fault in the gene that makes enzyme 2, which metabolite would build up ?
Metabolite X
What name is given to a substance that decreases that rate of an enzyme controlled reaction ?
An inhibitor
Name two types of inhibitor
Competitive inhibitor and non competitive inhibitor
Which inhibitor binds to the active site and competes with the substrate in an enzyme controlled reaction ?
Competitive inhibitor
Why is the competitive inhibitor able to join to the active site of an enzyme ?
Because it has a similar shape to the substrate
What happens to the rebate of reaction in an enzyme controlled reaction that is affected by a competitive inhibitor ?
It decreases the rate of reaction, but doesn’t stop it altogether because the substrate can still bind sometimes
How could the effects of a competitive inhibitor be reversed ?
Increase the substrate concentration
Where does a non competitive inhibitor bind to ?
An allosteric site (site away from the active site)
What does a non competitive inhibitor do to the shape of an enzyme active site ?
Changes the shape of the active site
Why does a reaction affected by a non competitive inhibitor stop altogether ?
Because the shape of the active site has changed permanently and it no longer recognises the substrate
When an end product is made in a metabolic pathway some of the product goes back and inhibits an enzyme at the start of the pathway, what is this called ?
End product inhibition
