Enzymes: Key Concepts and Functions

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Questions and Answers

Match the following enzymes to their optimal pH:

Amylase = pH 7 Pepsin = pH 2 Lipase = pH 10 Trypsin = pH 8

Match the following terms to their definitions:

Denatured = Loss of enzyme shape and activity Co-enzymes = Helper substances for enzyme function Substrate = The substance on which an enzyme acts Inhibitors = Substances that decrease enzyme activity

Match the following environmental factors to their effects on enzymes:

Temperature above 40°C = Enzyme denaturation Optimal temperature around 37°C = Maximized enzyme activity Low pH = Inhibition of certain enzymes High substrate concentration = Possible saturation of enzyme activity

Match the following enzymes to their primary functions:

Amylase = Digestion of carbohydrates Lipase = Digestion of fats Pepsin = Digestion of proteins Catalase = Decomposition of hydrogen peroxide Signup and view all the answers

Match the following enzymes with their source:

Amylase = Saliva Pepsin = Stomach Lipase = Pancreas Trypsin = Small intestine Signup and view all the answers

Match the following vitamins to their role as co-enzymes:

Vitamin B1 = Co-enzyme in carbohydrate metabolism Vitamin B6 = Co-enzyme in amino acid metabolism Vitamin C = Antioxidant, not a co-enzyme Vitamin B12 = Co-enzyme in red blood cell formation Signup and view all the answers

Match the following factors affecting enzyme activity with their specific effects:

pH optimization = Specific range for each enzyme Increasing temperature = Boosts activity to a point Presence of inhibitors = Decreases enzyme function Enzyme concentration = Raises reaction rate up to saturation Signup and view all the answers

Match the following enzymes to their respective digestive systems:

Amylase = Mouth Pepsin = Stomach Lipase = Small intestine Trypsin = Small intestine Signup and view all the answers

Match the enzyme activity factor with its effect:

Temperature below 40°C = Resumes shape and activity Temperature above 50°C = Irreversible change occurs pH 1 = Denatures salivary amylase pH 7-8 = Optimal for carbohydrate digestion Signup and view all the answers

Match the process with the example:

Denaturation by heat = Egg whites turning stiff and white Denaturation by pH = Salivary amylase stopping carbohydrate digestion Denaturation by acid = Pickled beetroot Denaturation by agitation = Beaten egg whites with sugar Signup and view all the answers

Match the type of reaction with its description:

Anabolic reaction = Products are more complex than reactants Catabolic reaction = Products are smaller and less complex than reactants Substrate-product complex = Formed after reaction takes place Enzyme-substrate complex = Combination of substrate engaging with the active site Signup and view all the answers

Match the term with its definition:

Active site = Place on the enzyme where substrate fits Agitation = Shaking or beating that can denature enzymes Activation energy = Energy required to initiate a reaction Enzyme = Biological catalyst that speeds up reactions Signup and view all the answers

Match the substance with its function:

Benzoic acid = Preserves soft drinks Vinegar = Used for pickling vegetables like beetroot Albumen = Main constituent of egg whites Salivary amylase = Breaks down starch into fructose Signup and view all the answers

Match the biological change with the condition:

Temperature drop = Shape resumes Temperature rise = Enzyme denatures Acidic pH = Inhibits enzyme activity Neutral pH = Facilitates carbohydrate digestion Signup and view all the answers

Match the type of reaction with its example:

Anabolic = Making muscle Catabolic = Breaking down glucose Hydrolysis = Complex molecules broken down Condensation = Forming larger molecules from smaller units Signup and view all the answers

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Study Notes

Enzymes Overview

Enzymes are proteins that act as biological catalysts, accelerating chemical reactions without being consumed.
Each enzyme is specific to one substrate and produces only a specific set of products.
Made from long chains of amino acids linked by peptide bonds; their structure is folded into a unique 3D shape.

Co-enzymes

Some enzymes require additional molecules, known as co-enzymes, for optimal function.
Co-enzymes are organic, non-protein substances; vitamins B1 and B6 function in this role.
Enzyme names typically end with the suffix ‘-ase’.

Factors Affecting Enzyme Activity

Enzyme function is influenced by environmental conditions such as pH, temperature, concentration of enzymes, and substrates, as well as the presence of inhibitors.

pH Impact

Each enzyme has a specific pH range for optimal activity:
- Amylase: best at pH 7 (neutral).
- Pepsin: functions optimally around pH 2 (acidic), suited for the stomach.
- Lipase: works best at pH 10 (alkaline) in the small intestine.

Temperature Impact

Enzyme activity typically increases with temperature, peaking at around 40°C.
Above 40°C, enzymes rapidly denature, losing shape and function.
Human enzymes function optimally around 37°C but can become inactive above this temperature, particularly in the brain, risking seizures.
Plant enzymes thrive at an approximate optimum temperature of 25°C.

Denatured Enzymes

Denaturation refers to the loss of an enzyme's shape and activity, caused by several factors:
- High Temperature: Enzymes lose shape above 40°C; irreversible changes occur at temperatures exceeding 50°C. For example, egg whites transition from clear to stiff upon heating.
- pH Change: For instance, salivary amylase, which breaks down starch at pH 7-8 in the mouth, becomes inactive when exposed to the acidic environment (pH 1) in the stomach.
- Agitation: Physical mixing or beating can alter enzyme shape and activity, such as when egg whites are beaten, forming a thick mixture that traps sugar.

Active Site Theory

The active site is the specific region on the enzyme where the substrate binds and reactions occur.
The binding causes slight shape changes in both substrate and enzyme, forming an enzyme-substrate complex.
These transformations facilitate product formation and lower activation energy needed for the reaction.
Resulting products may form a substrate-product complex, allow the enzyme to revert to its original shape, ready to catalyze another reaction.

Types of Reactions

Anabolic Reactions: Create more complex products from simpler reactants; e.g., muscle formation.
Catabolic Reactions: Break down complex reactants into simpler products; oppositely, they release energy.