Enzymes Flashcards
What are enzymes?
Biological catalysts that slow down or speed up a reaction without being used up in the process.
Enzymes are crucial for various biochemical reactions in living organisms.
What is the nature of enzymes?
Enzymes are proteins.
They have specific structures that determine their function.
What is the shape of enzymes?
They have a 3D folded (globular) shape.
This shape is essential for their activity.
What is a substrate?
The substance that an enzyme works on, altering the rate of the reaction.
Substrates are specific to each enzyme.
What is a product in enzymatic reactions?
The substance produced as a result of the enzyme working on the substrate.
Products are released after the reaction is complete.
Provide an example of a substrate, product, and enzyme.
Substrate: starch, Product: maltose, Enzyme: amylase.
This example illustrates the enzyme’s function in breaking down starch.
What are anabolic enzymes?
Enzymes that make small molecules into larger molecules, e.g. RNA polymerase builds RNA.
Anabolic processes are crucial for building cellular components.
What are catabolic enzymes?
Enzymes that break down large molecules into smaller molecules, e.g. amylase breaks down starch to maltose.
Catabolic processes provide energy and building blocks for cellular activities.
What is the active site of an enzyme?
The part of the enzyme that combines with the substrate.
The active site is critical for enzyme specificity.
What does enzyme specificity refer to?
Each enzyme only works on a particular substrate (lock and key mechanism).
This specificity is essential for proper metabolic function.
What is the induced fit model?
The substrate joins with the active site, causing the active site to change shape slightly to accommodate the substrate.
This model explains how enzymes enhance the likelihood of a reaction.
What is formed when the enzyme and substrate combine?
An enzyme-substrate complex.
This complex is a crucial step in the enzymatic process.
What happens after products are formed in an enzymatic reaction?
Products are released from the active site.
This release allows the enzyme to catalyze another reaction.
What happens to the active site of an enzyme after it reacts with a substrate?
The active site reverts to its original shape, ready to join with another substrate molecule of the same type.
What are the optimum conditions for enzyme activity?
Specific temperatures, pHs, substrate concentrations, and enzyme concentrations.
What occurs to enzymes below certain temperatures?
They cannot move and so cannot react with their substrate due to lacking the required activation energy.
What happens to enzymes above certain temperatures?
They become denatured, lose their shape permanently, and cannot bond efficiently with their substrate.
At what temperature do human enzymes work best?
Around 37 degrees (body temperature).
What pH range do enzymes generally work best in?
Usually between 6-8.
What happens to enzymes outside their optimum pH range?
They become denatured and cannot bond with their substrate.
What is bio-processing?
The use of enzymes to alter the rates of the reactions occurring.
List some products made by bio-processing.
- Cheese
- Beer
- Antibiotics
- Vaccines
What does it mean for enzymes to be immobilised?
Enzymes are attached to each other or to an inert substance, like a gel.
What is an example of a substance that can immobilise enzymes?
Sodium alginate.
What are the advantages of enzyme immobilisation?
- Enzymes can be re-used
- Enzymes produce a purer product
- Enzymes are more stable
What is the role of lactase in bio-processing?
It acts on lactose and breaks it down to glucose and galactose to make lactose-free products.
Describe an experiment to investigate the effect of temperature on an enzyme.
Blend celery to extract catalase, filter it, pour into graduated cylinders, add washing up liquid, and then add pH 7 buffer.
What enzyme is contained in celery?
Catalase
Catalase is an enzyme that catalyzes the decomposition of hydrogen peroxide into water and oxygen.
What is the purpose of boiling the celery mixture?
To denature the enzyme
Denaturation alters the enzyme’s structure, rendering it inactive.
What is added to each graduated cylinder to facilitate the reaction?
A drop of washing up liquid
Washing up liquid helps to trap the oxygen produced by the reaction, forming foam.
What is the optimum pH used in the experiment?
pH 7
This pH is considered neutral and is optimal for many enzymes, including catalase.
What is the optimum temperature used in the experiment?
25 degrees Celsius
This temperature is optimal for the activity of catalase.
What is the substrate used in the experiment?
Hydrogen peroxide
Hydrogen peroxide is the substance that is broken down by the enzyme catalase.
What is measured to assess the activity of the enzyme?
Volume of foam produced
The foam indicates the production of oxygen gas as a result of the enzymatic reaction.
What was the conclusion regarding the denatured catalase?
No foam was produced
This indicates that the denatured enzyme was inactive and could not facilitate the reaction.
What enzyme is contained in yeast?
Sucrase
Sucrase is an enzyme that catalyzes the hydrolysis of sucrose into glucose and fructose.
What substance is mixed with water to immobilize the enzyme in yeast?
Sodium alginate
Sodium alginate forms a gel that traps the enzyme, allowing it to remain active while being separated from the reaction mixture.
What solution is prepared to harden the gel beads?
Calcium chloride solution
Calcium ions help to cross-link the sodium alginate, forming solid beads.
What is the control in the enzyme immobilization experiment?
Yeast solution in a separating funnel
This serves as a comparison to the beads containing the immobilized enzyme.
What is the substrate used in the enzyme immobilization experiment?
Sucrose solution
Sucrose is the substance that will be hydrolyzed by the sucrase enzyme.
What product is tested every minute using glucose test strips?
Glucose
The production of glucose indicates that the enzyme is active and successfully breaking down sucrose.
What is produced faster in the control?
Glucose
The control refers to a setup without modifications that allows for faster glucose production.
What characteristic does the control solution have?
Cloudy solution
This may indicate the presence of impurities or suspended particles.
What solution is mentioned alongside sodium alginate?
SuCrose Solution
SuCrose solution may be used in experimental setups involving glucose production.
What type of beads are referenced?
Yeast beads
Yeast beads are often used in biochemical processes for their ability to aid in fermentation.
What is the purpose of immobilising the enzyme?
Produces a purer product
Immobilised enzymes can enhance the specificity and efficiency of reactions.
Fill in the blank: The enzyme produces glucose in a _______.
purer product
True or False: The immobilised enzyme produces a less pure product.
False
The immobilised enzyme is stated to produce a purer product compared to other methods.
What is a potential issue with beads in the process?
Beads stuck
This could hinder the efficiency of the reaction or the overall process.
