Chapter 7- Enzymes Flashcards
Which term refers to all chemical reactions in a cell?
Metabolism
What do enzymes do?
Speed up certain chemical reactions (act as catalysts)
What are the two parts of an enzyme?
- Apoenzyme: protein portion, accounts for enzyme’s ability to only run a single type of reaction
- Coenzyme: non-protein portion, can donate or accept atoms to or from a reaction
What is a substrate?
A reactant (raw material) that the enzyme acts on
How and where is thyroxin produced?
Thyroid gland accumulates iodine
Where is thyroxin secreted into?
The bloodstream
What does thyroxin have an overall impact on?
Enzyme activity and the body’s metabolism
What hormone regulates growth and development?
Thyroxin
What occurs when the body doesn’t have sufficient amounts of thyroxin?
Simple Goiter; thyroid gland enlarges
What happens when the body has excessive amounts of thyroxin?
Exothamic Goiter; enlarged thyroid gland and protrusion of eyeballs
What is the Lock and Key Theory of enzyme action?
- Substrates must be brought close together for the reaction to occur
- Substrates bond to active site on the enzyme
- Reaction occurs and products are released, enzyme goes back to tertiary shape
What must occur for a substrate to bond to an enzyme?
The enzyme must have the correct shape to bond with the substrate
What are the factors affecting enzyme activity?
- Heavy metals: can change their shape and denature them (non-competitive inhibition)
- Competitive Inhibition: interferes with active site so substrate cannot bond
- Temperature: too hot will denature enzyme, warm will speed up reaction, too cold makes reaction go slow
- pH: enzymes operate the best at preferred pH level
- Substrate Concentration: the rate of reaction increases with the increase of substrate concentration
- Enzyme Concentration: more enzyme, greater rate of reaction
What are two environmental factors that affect enzyme shape?
Temperature and pH levels
How and where is thyroxin produced?
Thyroid gland accumulates iodine
