S3 Biology Chapter 3: Enzymes and Metabolism

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Questions and Answers

What is the term used to describe the breaking-down reactions in an organism?

Catabolism (correct)

Metabolism

Anabolism

Photosynthesis

What is the energy requirement for anabolic reactions?

Energy is not involved

Energy is stored

Energy is required (correct)

Energy is released

What is the process by which starch is broken down into glucose during digestion?

Anabolic reaction

Catabolic reaction (correct)

Photosynthetic reaction

Metabolic reaction

What is the term used to describe the overall rate of chemical reactions of an organism?

Metabolic rate Signup and view all the answers

What type of reactions involve the synthesis of complex molecules from simpler ones?

Anabolic reactions Signup and view all the answers

What is the process by which energy-rich food substances are broken down into carbon dioxide and water to release energy during respiration?

Catabolic reaction Signup and view all the answers

What is the primary function of enzymes in living cells?

To speed up the rate of chemical reactions by lowering the activation energy Signup and view all the answers

What is the term for the energy required to start a chemical reaction?

Activation energy Signup and view all the answers

What is the role of enzymes in the metabolism of living organisms?

To speed up chemical reactions to facilitate metabolism Signup and view all the answers

What is the characteristic of enzymes that distinguishes them from other catalysts?

They are proteins produced by living cells Signup and view all the answers

What is the result of enzymes lowering the activation energy in a chemical reaction?

The reaction rate increases Signup and view all the answers

What is the term for the chemicals produced by living cells to speed up chemical reactions?

Enzymes Signup and view all the answers

What is the primary reason why the rate of most enzymatic reactions decreases rapidly when the temperature exceeds 50°C?

The chemical structures of the enzymes are changed at high temperatures Signup and view all the answers

What is the term for the temperature at which an enzyme's reaction rate is the fastest?

Optimum temperature Signup and view all the answers

What is the effect of extreme pH on an enzyme's activity?

It denatures the enzyme Signup and view all the answers

Why do enzymes have different optimum pH values?

Because their chemical structures are sensitive to pH changes Signup and view all the answers

What is the result of an enzyme's chemical structure being changed at high temperatures?

The enzyme's active site is unable to bind substrate molecules Signup and view all the answers

What is the term for the process by which an enzyme's chemical structure is altered, making it inactive?

Denaturation Signup and view all the answers

What is a characteristic of enzymes that allows them to be reused multiple times?

They are unchanged at the end of the reaction Signup and view all the answers

What is the primary reason why only small amounts of enzymes are required for catalysis?

Enzymes are highly efficient catalysts Signup and view all the answers

What is the term for the process by which an enzyme's structure is altered due to high temperatures or extreme pH?

Denaturation Signup and view all the answers

What is the specific shape on an enzyme molecule that allows it to combine with a substrate molecule?

Active site Signup and view all the answers

What is the unstable structure formed when an enzyme molecule combines with a substrate molecule?

Enzyme-substrate complex Signup and view all the answers

What is the primary reason why enzymes are specific in their actions?

They have a specific shape that only allows them to combine with specific substrate molecules Signup and view all the answers

What is the primary function of amylases in industrial applications?

Converting starch to maltose Signup and view all the answers

What is a characteristic of enzymes that makes them environmentally friendly?

They are biodegradable Signup and view all the answers

What is the role of proteases in tenderizing meat?

Breaking down proteins to form amino acids Signup and view all the answers

What is the advantage of using enzymes in industrial processes in terms of energy consumption?

They work under moderate temperature conditions Signup and view all the answers

What is the purpose of using cellulases in the production of stonewashed jeans?

Breaking down plant cellulose Signup and view all the answers

What is a common application of enzymes in daily life?

All of the above Signup and view all the answers

Study Notes

Enzymes and Metabolism

Metabolism refers to all chemical reactions that take place within a cell
Metabolism can be divided into catabolic processes (breaking-down reactions) and anabolic processes (building-up reactions)

Effect of Temperature on Enzymes

Enzymes are proteins, and their chemical structures can be changed by high temperatures
Above 50°C, the rate of most enzymatic reactions drops rapidly due to denaturation of enzymes
Each enzyme has its own optimum temperature, which is the temperature at which it works best

Effect of pH on Enzymes

Enzymes work within a narrow range of pH
Small changes in pH can greatly affect the activity of the enzyme
Each enzyme has its own optimum pH, and extreme pH can denature the enzyme

Metabolic Rate

Metabolic rate refers to the overall rate of chemical reactions of an organism
It is influenced by factors such as temperature, pH, and the presence of enzymes

Catalysts and Enzymes

Catalysts are chemicals that can speed up the rate of chemical reactions
Enzymes are biological catalysts that are proteins produced by living cells
Enzymes lower the activation energy required for chemical reactions to take place

Properties of Enzymes

Enzymes are biological catalysts that speed up reactions but remain unchanged at the end of the reactions
Enzymes are specific in their actions and can usually catalyze only one particular reaction
Enzymes are reusable and only a small amount is needed for reactions

How Enzymes Work

Enzyme molecules have an active site with a specific shape that combines with substrate molecules to form an enzyme-substrate complex
The complex breaks down to release the product molecule(s) and the enzyme molecule, which remains unchanged

Enzymes in Human Body and Daily Life

Enzymes can be found along the alimentary canal and speed up the breaking-down of food substances
Enzymes have various applications in daily life, such as in the production of syrups, fruit juices, bread, and jeans
Enzymes are biodegradable, specific in action, and can reduce the production of unwanted products, making them environmentally friendly and energy-saving

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Description

Test your knowledge on metabolism, the chemical reactions that occur within a cell, and its two main processes: catabolic and anabolic. Learn about enzymes and their role in facilitating these reactions.