Enzymes and Digestion

What is the role of digestive enzymes?

They help break down food into smaller, absorbable molecules.

Where are digestive enzymes produced?

They are produced by specialized cells in glands and the gut lining.

What enzyme is produced by the salivary glands?

Amylase.

What is the function of bile in digestion?

Bile neutralizes stomach acid and emulsifies fats.

What does the stomach produce to aid digestion?

The stomach produces protease enzyme (pepsin) and hydrochloric acid.

What is the pH level of the stomach acid?

The pH level is around 2, which is acidic.

What is the function of the pancreas in digestion?

The pancreas produces protease, amylase, and lipase enzymes and releases them into the small intestine.

What is the role of the small intestine?

The small intestine produces enzymes for digestion and absorbs digested food into the bloodstream.

What happens in the large intestine?

Excess water is absorbed from the food.

What is the function of the gall bladder?

The gall bladder stores bile before it is released into the small intestine.

What are the three types of enzymes involved in digestion?

Carbohydrases, proteases, and lipases.

What do carbohydrases do?

They convert carbohydrates into simple sugars.

What do proteases do?

They convert proteins into amino acids.

What do lipases do?

They convert lipids into glycerol and fatty acids.

What is the main product of starch digestion?

Maltose and other sugars.

How does bile assist in fat digestion?

Bile emulsifies fats, increasing the surface area for lipase action.

What is the digestive process of starch in the mouth?

Amylase in saliva breaks down starch into maltose.

What is the role of hydrochloric acid in the stomach?

It kills bacteria and provides the right pH for pepsin to work.

What is the rectum's function in the digestive system?

The rectum stores feces before they are expelled from the body.

What type of molecules do digestive enzymes break down?

They break down large molecules like starch, proteins, and fats into smaller, absorbable molecules.

What is the significance of the alkaline conditions created by bile?

Alkaline conditions are necessary for enzymes in the small intestine to function effectively.

What is the purpose of using a dropping pipette in the experiment?

To take a fresh sample from the boiling tube every 30 seconds.

What indicates that starch is no longer present in the solution?

The iodine solution remains browny-orange.

How can you investigate the effect of pH on amylase activity?

By repeating the experiment with buffer solutions of different pH values.

What must be controlled to ensure a fair test in the enzyme experiment?

Variables such as concentration and volume of amylase solution.

How is the rate of reaction calculated?

By dividing the amount of change by the time taken.

What is the rate of reaction if 24 cm³ of oxygen is produced in 50 seconds?

0.48 cm³/s.

What is the effect of temperature on enzyme reactions?

Raising the temperature can speed up reactions but can also damage cells if too high.

What is a catalyst?

A substance that increases the speed of a reaction without being changed or used up.

What are enzymes made of?

Enzymes are large proteins made up of chains of amino acids.

What is the 'lock and key' model of enzyme action?

It describes how the substrate must fit into the enzyme's active site for the reaction to occur.

What happens to an enzyme when it is denatured?

The shape of the enzyme's active site changes, preventing the substrate from fitting.

What is the optimum temperature for enzyme activity?

The temperature at which the enzyme is most active.

What effect does high or low pH have on enzymes?

It can damage the bonds in the enzyme, changing the shape of the active site and denaturing the enzyme.

What is the optimum pH for most enzymes?

Often neutral pH 7, but can vary; for example, pepsin works best at pH 2.

What is the role of enzymes in living organisms?

To act as biological catalysts that speed up chemical reactions without the need for high temperatures.

How can you adapt the amylase experiment to investigate temperature effects?

By using a water bath set to different temperatures.

What is the significance of the active site in enzyme function?

The active site is where the substrate binds, and its shape is crucial for the reaction to occur.

What does it mean for an enzyme to be unchanged after a reaction?

The enzyme can be reused for subsequent reactions without being consumed.

What is the relationship between enzyme concentration and reaction rate?

Increasing enzyme concentration generally increases the reaction rate, provided substrate is available.

What is the effect of substrate concentration on enzyme activity?

Higher substrate concentrations can increase the rate of reaction until the enzyme becomes saturated.

What is the importance of controlling variables in enzyme experiments?

To ensure that the results are due to the factor being tested, such as pH or temperature.

What happens to enzyme activity at temperatures above the optimum?

Enzyme activity decreases as the enzyme may denature.

What is the role of buffers in enzyme experiments?

To maintain a constant pH during the reaction.

How does the structure of enzymes relate to their function?

The unique shape of enzymes allows them to catalyze specific reactions.

What is meant by the term 'reaction rate'?

The speed at which reactants are converted into products in a chemical reaction.