FC4 Unit 4 AOS 2 Altering Enzyme activity

Chemistry with Dr Ellis

17 Jul 202125:35

EducationalLearning

32 Likes 10 Comments

TLDRThis educational video delves into the intricate world of enzyme activity, focusing on how various factors influence their function. It explains the importance of enzymes' three-dimensional shape and active site, which are crucial for substrate binding and catalyzing reactions. The script covers the optimal conditions for enzyme activity, including substrate concentration, pH, and temperature, and how deviations can lead to denaturation. It also touches on the role of vitamin C as a coenzyme in collagen synthesis, emphasizing the significance of chirality in biological molecules. The video prepares viewers for a practical SAC on enzyme kinetics, fostering a deeper understanding of these biological catalysts.

Takeaways

🧬 Enzymes are proteins that catalyze reactions in the body and their activity is influenced by their three-dimensional shape and active site.
🔒 The 'lock and key' and 'induced fit' models describe how enzymes bind to substrates, and any change in the enzyme's shape can disrupt this binding.
📈 Enzyme activity is defined as the amount of substrate converted into product per unit time and is influenced by enzyme and substrate concentrations.
🔍 The maximum turnover (Vmax) of an enzyme occurs when all enzyme molecules are bound with substrate and cannot break down any more.
⚗️ Reaction conditions such as pH and temperature can significantly affect enzyme activity by altering the enzyme's tertiary structure and active site.
📊 Enzyme activity plots show the relationship between factors like temperature, pH, and substrate concentration with the rate of reaction.
🌡️ Enzymes have an optimal temperature and pH range at which they function best, typically around 36-37 degrees Celsius and pH 7 for human enzymes.
🍳 Denaturation refers to the irreversible loss of enzyme function due to the disruption of the protein's three-dimensional structure, which can be caused by extreme pH or temperature changes.
🧫 An enzyme assay is an experiment to determine enzyme activity, often using indicators to detect the presence of the reaction product.
💊 Vitamin C, or ascorbic acid, is an essential coenzyme in the human body, particularly for collagen synthesis, and its chirality is significant for its function.
📝 Understanding the role of coenzymes, such as vitamin C, involves discussing both their physical binding to enzymes and their chemical role in facilitating reactions.

Q & A

What is the primary role of enzymes in the body?
-Enzymes are proteins that act as biological catalysts, facilitating specific biochemical reactions within the body.
Why is the three-dimensional shape of enzymes important?
-The three-dimensional shape of enzymes is crucial because it determines the formation of the active site, which is responsible for catalyzing particular reactions.
What are the two models that describe substrate binding to enzymes?
-The two models that describe substrate binding to enzymes are the lock and key model, and the induced fit model.
How does the concentration of the enzyme affect the rate of reaction?
-The concentration of the enzyme affects the rate of reaction because a higher concentration of enzyme allows for more substrate binding, thus increasing the rate of reaction up to the point of saturation.
What is meant by 'Vmax' in the context of enzyme kinetics?
-Vmax refers to the maximum rate of reaction that an enzyme can achieve when all of its active sites are saturated with substrate.
What factors can affect enzyme activity and the rate of catalysis?
-Factors that can affect enzyme activity and the rate of catalysis include the concentration of the substrate, the presence of the enzyme, and the reaction conditions such as pH and temperature.
What is the relationship between temperature and enzyme activity?
-As temperature increases, enzyme activity generally increases due to higher kinetic energy and more frequent binding events between the substrate and the enzyme. However, beyond a certain optimal temperature, the enzyme's structure may become unstable, leading to a decrease in activity and eventual denaturation.
What is the significance of pH on enzyme activity?
-pH can significantly affect enzyme activity because it can alter the ionization of the amino acid side chains, which in turn can disrupt the enzyme's tertiary structure and active site, leading to a loss of function.
What is denaturation in the context of enzymes?
-Denaturation refers to the process where the tertiary structure of an enzyme is disrupted, leading to a loss of its biological activity. This can occur due to changes in pH, extreme temperatures, or the presence of certain chemicals.
How does the body maintain optimal conditions for enzyme activity?
-For human systems, the optimal conditions for enzyme activity are typically around a body temperature of 36 to 37 degrees Celsius and a pH range of 7 to 8, which are maintained for healthy enzyme function.
What is an enzyme assay, and why is it used?
-An enzyme assay is an experimental procedure used to determine enzyme activity. It often involves using indicators to detect the presence of the product of the enzymatic reaction, allowing for the measurement of the enzyme's catalytic effect on the reaction rate.
Why is vitamin C essential in the human body, and what is its role in collagen synthesis?
-Vitamin C is essential in the human body because it acts as a coenzyme in various biochemical reactions, including the production of collagen. It serves as an electron donor in the synthesis process, which is vital for maintaining the structural integrity of connective tissues and preventing conditions like scurvy.
What is the significance of the chirality of amino acids and vitamin C in biological systems?
-Chirality is significant because it affects how amino acids and molecules like vitamin C interact with other chiral compounds in the body. This is important for their function, as only specific optical isomers, like L-ascorbic acid in the case of vitamin C, are biologically active.
What is the role of proline in collagen, and how is its zwitterion form different?
-Proline is the second most common amino acid in collagen and is unique because its side chain forms a ring structure with the backbone, creating a cyclic structure. Its zwitterion form involves the ionization of the carboxyl group and the amino group, which is important for its interactions within the collagen structure.

Outlines

00:00

🧬 Enzyme Activity and Its Influencing Factors

This paragraph introduces the topic of enzyme activity, focusing on the factors that affect it. Enzymes, as proteins, have a specific three-dimensional shape with an active site that catalyzes reactions. The stability of this shape, maintained by interactions between amino acid side chains, is crucial for enzyme function. Any change in shape can disrupt the enzyme's activity. The concept of enzyme activity is defined in terms of substrate conversion into product per unit time, which depends on the concentration of the active enzyme and substrate. The maximum turnover (Vmax) is reached when all enzyme molecules are bound with substrate. Reaction conditions, such as pH and temperature, can also affect enzyme activity by altering the enzyme's tertiary structure, potentially leading to a loss of function.

05:02

🌡️ Optimal Conditions for Enzyme Activity

The paragraph discusses the optimal conditions necessary for maximum enzyme activity, including temperature and pH ranges. Enzymes have an optimum pH and temperature at which they function best, typically around 36-37 degrees Celsius and a pH of 7 to 8 for human body enzymes. Deviations from these optimal conditions can lead to a decrease in enzyme activity. The paragraph also explains how enzyme activity plots illustrate the relationship between substrate concentration and reaction rate, showing an initial increase followed by a plateau as enzymes become saturated with substrate. Different enzymes have different optimal pH values depending on their location in the body, such as the highly acidic environment of the stomach for pepsin and the near-neutral pH of the mouth for salivary amylase.

10:05

🔍 The Impact of pH and Temperature on Enzyme Structure

This section delves into how changes in pH and temperature can significantly affect enzyme structure and function. Extreme pH levels can cause enzyme denaturing, altering the overall three-dimensional shape and preventing substrate binding. Temperature influences enzyme activity as well, with lower temperatures reducing activity due to fewer successful collisions between enzyme and substrate, and higher temperatures leading to the destabilization and denaturation of the enzyme's active site. Denaturation refers to the disruption of the enzyme's tertiary structure, which can be permanent, resulting in the loss of all enzyme function. The paragraph also explains coagulation, a process where denatured proteins clump together, forming irreversible aggregates.

15:08

🧪 Enzyme Assays and the Role of Vitamin C in Collagen Synthesis

The paragraph describes an enzyme assay, an experimental method to measure enzyme activity, often involving indicators to detect the presence of a reaction product. It also touches on the importance of vitamin C (ascorbic acid) as a coenzyme in collagen synthesis. Vitamin C, being optically active, can exist in different isomers, but only one form is active in the human body. As a coenzyme, vitamin C acts as an electron donor, facilitating the enzyme's ability to catalyze collagen production. A deficiency in vitamin C can lead to scurvy, emphasizing its essential role in human health.

20:08

📚 Understanding Enzyme Activity and Vitamin C through Exam Questions

This section reviews exam questions related to enzyme activity and the role of vitamin C. It highlights common mistakes made by students, such as misunderstanding the concept of optical isomers and the specific role of vitamin C as a coenzyme. The paragraph emphasizes the need to understand the physical and chemical interactions of vitamin C with enzymes and how these interactions enable the enzyme to catalyze collagen production. It also points out the importance of being able to draw and interpret zwitterion structures of amino acids, such as proline, and the role of vitamin C in redox reactions.

25:09

📘 Conclusion and Preparation for Class

The final paragraph wraps up the video by mentioning that the class will practice answering exam questions related to the topics discussed. It encourages students to take notes on any areas of confusion and to prepare for in-class discussions. The instructor expresses a commitment to addressing students' questions and ensuring they understand the material.

Mindmap

Keywords

💡Enzyme Activity

Enzyme activity refers to the rate at which an enzyme catalyzes a specific biochemical reaction, which is crucial for understanding the function of proteins within the body. In the video, it is discussed how the enzyme's three-dimensional shape and active site are critical for substrate binding and catalysis. The concept is central to the theme of the video, as it explores factors that can affect this activity, such as substrate concentration, pH, and temperature.

💡Active Site

The active site is the region of an enzyme where the substrate binds and the chemical reaction occurs. Defined by the specific three-dimensional shape of the enzyme, the active site is essential for enzyme activity. The video script explains that any change in the shape of the active site can disrupt enzyme function, emphasizing its importance in the lock-and-key and induced fit models of substrate binding.

💡Substrate

A substrate is the molecule upon which an enzyme acts to catalyze a chemical reaction. The script discusses how the concentration of the substrate influences enzyme activity, with the rate of reaction increasing until the enzyme becomes saturated with substrate, reaching its maximum turnover (Vmax).

💡Enzyme Assay

An enzyme assay is an experimental procedure used to determine the activity of an enzyme. The script mentions that this assay often involves the use of indicators to detect the presence of the product formed by the enzyme-catalyzed reaction. It is a practical application of understanding enzyme activity, allowing for the measurement of how effectively an enzyme performs its function.

💡pH

pH is a measure of the acidity or alkalinity of a solution and is a critical factor affecting enzyme activity. The video script explains how different enzymes have optimal pH ranges in which they function best. For example, pepsin is most active in the highly acidic environment of the stomach (pH around 1.5), whereas salivary amylase functions optimally at a pH close to neutral (around 7.2).

💡Temperature

Temperature is another key factor influencing enzyme activity. The script describes how increasing temperature initially increases the rate of enzyme-catalyzed reactions due to increased kinetic energy and molecular movement. However, temperatures that are too high can lead to the denaturation of the enzyme, resulting in a loss of function.

💡Denaturation

Denaturation refers to the irreversible loss of an enzyme's three-dimensional structure and function, often caused by extreme changes in pH or temperature. The video script explains that denaturation disrupts the intermolecular forces stabilizing the enzyme's structure, leading to the loss of its specific shape and, consequently, its activity.

💡Coagulation

Coagulation is the process where proteins, including enzymes, clump together and form a tangled, irreversible mass. The script uses the example of frying an egg to illustrate coagulation, where the proteins in the egg white and yolk denature and then coagulate, resulting in the solidification of the egg.

💡Collagen

Collagen is a protein that plays a vital role in the structure of the body's connective tissues. The video script mentions that vitamin C acts as a coenzyme in collagen synthesis, highlighting its importance in the human diet and its role in preventing conditions like scurvy, which is caused by a deficiency of vitamin C.

💡Coenzyme

A coenzyme is a molecule that works in conjunction with an enzyme to facilitate a biochemical reaction. The script explains that vitamin C, as a coenzyme, is essential for collagen synthesis, acting as an electron donor in the process. This illustrates the importance of coenzymes in enzyme function and the broader context of biochemistry.

Highlights

Enzymes have a specific three-dimensional shape with an active site that catalyzes reactions.

Loss of enzyme shape can disrupt activity and substrate binding.

Enzyme activity defined as the amount of substrate converted into product per unit time.

Enzyme activity is dependent on the concentration of the active enzyme and substrate.

Vmax represents the maximum turnover of an enzyme when all are bound with substrate.

Reaction conditions, such as pH and temperature, affect enzyme activity by altering the active site.

Enzyme activity plots show the relationship between temperature or pH and reaction rate.

Optimum pH and temperature are critical for enzyme function in biological systems.

Human body temperature and pH have optimal ranges for enzyme activity.

Different enzymes have different optimal pH levels depending on their location in the body.

Extreme pH changes and temperatures can cause enzyme denaturation and loss of function.

Denaturation refers to the disruption of the protein's tertiary structure leading to loss of activity.

Coagulation is the irreversible clumping of protein strands after denaturation.

Enzyme assays are used to determine enzyme activity through various detection methods.

Vitamin C (L-ascorbic acid) is an essential coenzyme in collagen synthesis.

Proline is an unusual amino acid with a ring structure in its side chain.

Vitamin C acts as an electron donor and is involved in the reduction reactions in collagen synthesis.

Optical isomers, such as vitamin C, have the same structure but are mirror images and require a chiral carbon.

Transcripts

Browse More Related Video

Enzymes (Updated)

Enzymes: Nature's Factory Workers

FC3 Unit 4 AOS2 Introduction to enzymes

Enzyme Catalysis and Substrate Binding | Active Site, Specificity, "Lock and Key" vs "Induced Fit"

Michaelis-Menten Kinetics: Considerations & Time Relation – Biochemistry | Lecturio

Endergonic and Exergonic Reactions; Feedback Inhibition

Related Tags

Enzyme Activity Food Chemistry Biological Systems Optimum Conditions Temperature Effects pH Influence Digestive Enzymes Collagen Synthesis Vitamin C Role Enzyme Assay Protein Denaturation