Enzymes Flashcards
What is activation energy?
The energy requires for a reaction to take place.
How do enzymes affect activation energy?
They reduce the amount of activation energy required in a reaction.
What is an extracellular enzyme?
An enzyme that functions within the digestive system and assists in digestive processes.
What is an intracellular enzyme?
An enzyme that functions inside cells and assists in metabolic processes.
Why are enzymes involved in respiration important for an organism?
Because without them the organism would not respire at the rate required for survival.
What is the “lock and key” model?
It describes the nature of enzyme active sites: all enzymes have different shaped active sits that will only match up with their specific substrates - similar to a lock and key.
What is an anabolic reaction?
When multiple substrates form a singular product.
What is a catabolic reaction?
When a singular substrate gets broken up into multiple products.
Where is the place that enzymes and substrates join?
The active site.
What is the name used to refer to an enzyme and substrate joined together?
An enzyme-substrate complex.
Provide three examples of reactions that require the help of enzymes.
Respiration, cell replication, photosynthesis.
What is an enzyme?
A biological catalyst.
Where are enzymes made?
In ribosomes.
What is point of saturation?
When, at a given time, all enzyme active sites are occupied by substrates.
What is a competitive inhibitor?
Something that binds to the active site of an enzyme, directly blocking the substrate binding with it.
What is a non-competitive inhibitor?
Something that binds to the enzyme, not at the active site, resulting in a shape change at the active site.
What are cofactors?
Inorganic substances that bind to enzymes, helping stabilise or directly assist with a reaction.
What are coenzymes?
Organic substances that bind to the active site alongside the substrate. They assist in catalysing the reaction.
Describe the relationship between substrate concerntration and rate of reaction.
As the substrate concerntration increases, so does the rate of reaction, until point of saturation is reached where all active site are occupied by substrates. At this point, the reaction rate neither increases nor decreases.
Describe the relationship between enzyme concerntration and rate of reaction.
Directly proportional. As enzyme concerntration increases, so does the rate of reaction.
What is the “induced fit” model?
The active site is not a rigid structure, meaning the enzyme can slightly change shape in order to bind with the substrate. When the products are released, the enzyme reverts back to its original form.
In a biological reaction, what name is given to the reactants?
Substrates.
