Catalysts and enzymes Flashcards
What is another name for enzymes?
Biological catalysts
What are catalysts?
Chemicals that speed up a chemical reaction without being used up in the reaction
What do enzymes interact with?
Substrates
What are substrates?
Reactants
What are enzymes made of?
Large protein molecules
How are enzymes made?
Long chains of amino acids are folded to produce a molecule with a specifically shaped active site (so it can bind to a specific substrate molecule)
What is the theory called that explains how enzymes work?
The lock and key theory
What can enzymes do to substrates?
- Break up large molecules
- Combine small molecules
What part of the ‘lock and key model’ is the enzyme?
Lock
What part of the ‘lock and key model’ is the substrate?
Key
What is metabolism?
The sum of all reactions in a cell or organism
What do enzymes change and not change?
- Change: Metabolism
- Not change: The reaction itself
What small molecules are combined by enzymes?
- Glucose
- Amino acids
- Fatty acids
What molecules are built from glucose?
- Starch
- Glycogen
- Cellulose
What molecules are built from fatty acids?
Lipids
What molecules are built from amino acids?
Proteins
What are some molecules made by plant enzymes? (reactants and products)
- Glucose (carbon dioxide + water)
- Amino acids (nitrate ions + glucose)
What molecules are changed into other molecules by enzymes? (reactants and products)
- Glucose -> Fructose
- One amino acid -> another amino acid
What molecules are broken down by enzymes?
- Carbohydrates
- Lipids
- Proteins
- Glucose
- Excess amino acids
What do excess amino acids break down into?
- Urea
- Molecules used for respiration
What is hydrogen peroxide? (and how does it interact with enzymes)
- A poisonous byproduct of reactions in cells.
- It breaks down naturally into water and oxygen, however enzymes speed up the process so that it breaks down without causing any damage.
What factors affect enzyme activity?
- Temperature
- PH
How does temperature affect enzyme activity?
- Cold temperatures slow how fast the enzyme catalyzes reactions, but cold temperatures don’t denature the enzyme.
- Hot temperatures make enzymes more efficient, until about 40°C (for most enzymes)
- If enzymes get too hot (about 40°C+), they denature.
What does denature mean?
When an enzyme stops working permanently
