c1.1 enzymes and metabolism Flashcards
(29 cards)
What is a catalyst?
A substance that speeds up a chemical reaction without being consumed.
Why can enzymes be reused?
They speed up reactions without being permanently altered.
What role do enzymes play in life’s chemical reactions?
They accelerate reactions necessary for metabolism and biological processes.
What is metabolism?
The sum of all chemical reactions occurring in an organism.
What does enzyme specificity mean?
Enzymes have unique shapes that bind only to specific substrates.
How do enzymes regulate metabolism?
They control reaction rates and pathways through activation or inhibition.
Difference between anabolic & catabolic reactions?
- Anabolic: Build complex molecules, require energy.
- Catabolic: Break down molecules, release energy.
Examples of anabolic processes?
- Protein synthesis
- DNA replication
- Photosynthesis
Examples of catabolic processes?
- Cellular respiration
- Digestion
- Glycolysis
Properties of globular proteins?
Compact, soluble, spherical, functional (e.g., enzymes).
How does enzyme structure affect specificity?
The unique 3D active site fits only specific substrates.
What is the function of an enzyme’s active site?
It binds the substrate, facilitating reaction conversion.
Stages of enzyme catalysis?
- Substrate binds to active site.
- Reaction occurs.
- Product is released.
What is the induced-fit model?
Active site adjusts slightly to fit the substrate, improving binding.
How do random collisions help enzyme-substrate binding?
Molecular motion increases interactions for reactions to occur.
Compare enzyme and substrate movement in different environments.
- Cytoplasm: Free-floating molecules collide.
- Large substrates: Slow movement requires specific positioning.
- Immobilized enzymes: Fixed enzymes capture substrates efficiently.
Why do enzymes vary in specificity?
Different enzymes recognize unique substrates due to shape and charge.
What is denaturation?
Loss of enzyme shape, leading to loss of function.
Causes & effects of denaturation?
- Causes: Extreme temperature, pH changes.
- Effects: Active site distortion, inability to bind substrates.
How does temperature affect enzymes?
Higher temperatures increase collisions but can denature enzymes.
How does pH affect enzymes?
Extreme pH disrupts bonds, altering enzyme shape and function.
How does substrate concentration affect enzyme activity?
Higher substrate levels increase reaction rates until enzymes are saturated.
Identify manipulated (independent), responding (dependent), and controlled variables in enzyme experiments.
- Independent: Temperature, pH, substrate concentration
- Dependent: Reaction rate
- Controlled: Same enzyme type, same reaction conditions
Unit for enzyme reaction rate?
mol/s (moles per second)
