Enzymes Flashcards

Questions and Answers

What is the equation for photosynthesis?

6CO2 + 6H2O + energy = C6H12O6 + 6O2

What are chemical reactions?

When molecules are broken down to form other molecules

What is required for a reaction to occur?

Reactants must collide with enough energy

What is activation energy?

The amount of energy that reactants must absorb to become activated and start a chemical reaction Signup and view all the answers

What are biochemical reactions?

The chemical reactions in a cell Signup and view all the answers

What is the sum of all reactions in a cell?

Metabolism Signup and view all the answers

For a cell to survive it must have a fast what?

Metabolism Signup and view all the answers

Enzymes are biological what?

Catalysts Signup and view all the answers

How do enzymes increase the rate of reaction?

They lower the activation energy Signup and view all the answers

How many times can enzymes be reused?

Infinitely Signup and view all the answers

What is the reactant that acts with an enzyme?

A substrate Signup and view all the answers

Substrates fit specifically into what on an enzyme?

Its active site Signup and view all the answers

Substrate and enzyme are also known as a what model?

Lock and key Signup and view all the answers

What is induced fit?

When a substrate binds to an active site, slightly changing to get a grip on the substrate Signup and view all the answers

What happens when an induced fit strains the bond of the substrate?

It weakens the bonds between the substrate and enzyme Signup and view all the answers

What is the catalytic cycle of an enzyme (4 steps)?

<ol> <li>Enzyme's active site becomes available for the substrate 2. Substrate enters the active site and attaches by weak bonds 3. The weakened bond of substrate is hydrolyzed and converted to products 4. Products are released</li> </ol> Signup and view all the answers

What are the factors that affect the speed of chemical reactions and enzymes?

Amount of substrate, amount of enzymes, temperature, pH, inhibitors Signup and view all the answers

How do the amount of substrates and enzymes increase the rate of reaction?

It increases the chances of substrates bonding with enzymes Signup and view all the answers

How does temperature increase the rate of reaction?

Things speed up when heated, so they bump into each other faster Signup and view all the answers

How does pH increase the rate of reaction?

Optimal pH is usually 7, but some enzymes can handle lower values Signup and view all the answers

How do competitive inhibitors decrease the rate of reaction?

They prevent the substrate from bonding with an enzyme Signup and view all the answers

How do non-competitive inhibitors decrease the rate of reaction?

They bond with the enzyme's allosteric site Signup and view all the answers

Enzymes flat line when all enzymes are what?

Full or busy Signup and view all the answers

What happens to an enzyme after the reaction?

It releases the products and emerges unchanged Signup and view all the answers

What is a catalyst?

Something that increases the rate of chemical reaction Signup and view all the answers

What is feedback inhibition?

When a metabolic reaction is blocked by its products Signup and view all the answers

Why is inhibition important?

To regulate the cell metabolism Signup and view all the answers

How do antibiotics work?

They inhibit enzymes that are necessary for the bacteria to grow Signup and view all the answers

Study Notes

Photosynthesis

Photosynthesis equation: 6CO2 + 6H2O + energy = C6H12O6 + 6O2

Chemical Reactions

Definition: Process where molecules are broken down or transformed into other molecules.
Reactants must collide with sufficient energy for reactions to occur.

Activation Energy

Defined as the energy required to activate reactants in order to initiate a chemical reaction.

Biochemical Reactions

Refers to the chemical reactions occurring within a cell, collectively known as metabolism.

Metabolism

Encompasses all reactions in a cell necessary for survival and proper function.

Enzymes

Biological catalysts that speed up reactions by lowering activation energy.
Can be reused infinitely after reactions.

Substrates and Enzymes

Substrate: The reactant that interacts with an enzyme.
Fits specifically into the enzyme's active site, demonstrating the "lock and key" model.
Induced fit describes the slight change in shape of an enzyme's active site when a substrate binds, enhancing grip.

Catalytic Cycle of Enzymes

Four main steps:
- Active site becomes available for a substrate.
- Substrate attaches via weak bonds; induced fit occurs.
- Weakened bonds are hydrolyzed, converting substrate to product.
- Products are released; enzyme remains unchanged.

Factors Affecting Reaction Rates

Factors include substrate and enzyme concentrations, temperature, pH levels, and presence of inhibitors.

Temperature and pH Effects

Increased temperature accelerates reactions by increasing molecular activity, although excessive heat can denature enzymes.
Optimal pH is typically around 7; specific enzymes, like those in the stomach, can function in more acidic environments (pH 2-3).

Inhibitors

Competitive inhibitors mimic substrates and block the enzyme's active site, reducing reaction rates.
Non-competitive inhibitors bind to the enzyme's allosteric site, altering the active site's shape and preventing substrate binding.

Enzyme Activity

Enzymes become inactive when fully occupied by substrates (flatlining reaction rate).
Feedback inhibition occurs when product accumulation inhibits a metabolic pathway, regulating cell metabolism.

Antibiotics

Function by inhibiting specific bacterial enzymes necessary for growth, thereby controlling bacterial populations.

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Description

Test your knowledge on enzymes and their functions through these flashcards. Learn about essential processes like photosynthesis and chemical reactions. Perfect for biology students looking to reinforce their understanding of enzyme-related concepts.