Enzymes And Digestion

Question 1

What is the digestive system?

Answer 1

An organ system that breaks down food in mammals. It is also an exchange system (exchanges materials with the environment, takes in nutrients, releases bile)

Question 2

The digestive system is made up of several ORGANS. List all the ORGANS that take part in the digestive system and lost their purpose

Answer 2

Glands (salivary glands, pancreas): they produce digestive juices that digests food
Stomach (food is digested here)
The liver (produces bile)
Small intestine (food is digested into more soluble molecules that are then absorbed)
The colon (the large intestine): water is absorbed from undigested food, leaving faeces behind

Question 3

There are two ways that our food is broken down. What are they?

Answer 3

1st way: mechanical digestion (teeth grinds down the food and the food is sent to the stomach to churn it up)
2nd way: chemical digestion (digestive enzymes help break down the food)

Question 4

Digestion really only involves one type of reactions. What reaction is that?

Answer 4

Where large molecules of food are broken down into smaller molecules of food

Question 5

Why would we need the help of digestive enzymes in our digestive system?

Answer 5

They help catalyse the main reaction that happens in the system (breaking down large food molecules into smaller ones)

Question 6

Enzymes can be categorised into many types, and one of them is that they can split into enzymes that work inside of cells and enzymes that work outside of cells. Which category do digestive enzymes belong to?

Answer 6

Digestive enzymes work outside of body cells

Question 7

Where and how are digestive enzymes produced?

Answer 7

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

Question 8

What happens to enzymes after production?

Answer 8

They are then released and sent out to the gut to mix with food molecules so they can speed up the reactions that break them down

Question 9

Why do we need to break down big food molecules?

Answer 9

Starch, proteins and lipids are big molecules and big of this they can’t fit through the digestive system’s walls. We need to break them down so they can’t fit.

Question 10

What happens if we can’t break down the big food molecules?

Answer 10

If they can’t fit then they can’t be absorbed into the blood stream and sent to places in the body where they might be useful.

Question 11

How do we fix the problem of too big molecules? How are enzymes involved in this?

Answer 11

To get the big molecules to fit through the digestive system’s walls, we need to break them down into smaller molecules. Enzymes work to break down big molecules like starch, protein and lipid into smaller, more soluble materials such as sugars, amino acids , glycerol and fatty acids

Question 12

How does the body make use of the new smaller, soluble molecules broken down by enzymes?

Answer 12

Once these smaller, soluble molecules are absorbed into the blood stream, they are sent over the body. These products can be used to make new carbohydrates, proteins and lipids. But some of the other products can be used elsewhere. For example: glucose. It can used all around the body for respiration.

Question 13

What digestive enzyme is in charge of breaking down carbohydrates? What does this enzyme change carbohydrates into?

Answer 13

Carbohydrases are used to convert carbohydrates into simple sugars

Question 14

Give an example of an enzyme breaking down a carbohydrates and converting it.

Answer 14

Amylase is an example of a carbohydrase and it converts starch (a carbohydrate) into sugars like glucose and maltose

Question 15

Where are carbohydrases made and where do they work?

Answer 15

Carbohydrases are made in the small intestine and pancreas as well as the salivary glands. They work in the mouth and the small intestine

Question 16

What type of enzyme breaks down proteins? What are the proteins broken down into?

Answer 16

The enzyme protease breaks down protein. It converts it into amino acids

Question 17

Where are proteases made and where do they work?

Answer 17

Protease is made in the small intestine and the pancreas as well as the stomach. Protease works in the small intestine and the stomach

Question 18

What type of enzyme is in charge of breaking down lipids? What does the enzyme convert the lipids into?

Answer 18

Lipase is responsible for breaking down lipids. They converts lipids into fatty acids and glycerol

Question 19

Where are lipases made and where do they work?

Answer 19

Lipase is made in the small intestine and pancreas and it works in the small intestine

Question 20

Where is bile produced, stored and released?

Answer 20

Produced: liver
Stored: gall bladder
Released: small intestine

Question 21

What could potentially cause enzymes to denature in the digestive system?
What does bile do that benefits enzymes in terms of fixing that problem?

Answer 21

The stomach contains hydrochloric acid in it, making the conditions even all the way in the small intestine too acidic for enzymes to work in. Bile, is an alkaline, meaning when it’s released into the small intestine, it neutralised the acid and makes the small intestine conditions alkaline (perfect for the enzymes in this case)

Question 22

What does bile do specifically for lipids?

Answer 22

Bile emulsifies fat (lipids). So essentially, bile breaks down lipids into smaller chunks which then increases the surface area of the lipids which means more surface area for the enzyme lipase to work on which speeds up digestion