4.1 Biochemical pathways for chemical metabolism Flashcards
What are enzymes?
Catalysts in biochemical pathways
Are enzymes soluble in water?
Yes, most of the time
What is a substrate?
A molecule that an enzyme acts upon
What is an enzyme-substrate complex?
A structure where a substrate has bound with an enzyme
What is the structure of an enzyme?
A bundle of amino acids, forming the shape
What is enzyme specificity?
This determines how specific an enzyme is to its substrate.
What are the two models that can present enzyme specificity?
Lock and Key model and Induced-fit model
Explain the lock and key model
Only one size fits the shape; enzyme like a lock, substrate like a key; active site is assumed rigid
Explain the induced-fit model
Active site is assumed to be flexible and can fit around substrate tightly; active site is not complementary to substrate
What is a biochemical pathway?
The regulation of metabolic reactions; occurs in pathways that involve series of regulated steps controlled by enzymes; it is a negative feedback loop
Define catalytic power
The ability of an enzyme to increase the rate of a biochemical reaction, compared to the reaction occurring without the enzyme present
What is catabolism?
An exergonic reaction that releases energy and heat (exothermic); involves breaking down of a substrate and is involved in cellular respiration
What is anabolism?
An endergonic reaction that requires energy, making it endothermic; involves synthesis of new molecules and is involved in photosynthesis
What is activation energy?
An input of energy to start a reaction; enzymes allow for activation energy to reduce, so less energy is required from the body
What structure forms when a substrate binds to the active site of an enzyme?
An enzyme substrate complex
What model of enzyme so if it’s looks like a lock fitting in a key
Lock and key model
What model of enzyme specificity is similar to a glove changing shape as a hand slips into it?
The induced-fit model
What type of loop is a metabolic reaction?
A negative feedback loop
Is catabolism exergonic or endergonic?
Exergonic
Is anabolism exergonic or endergonic?
Endergonic