B3 - Digestive System and Enzymes (Y10 - Autumn 1)

Question 1

🟠 What are Cells

Answer 1

Cells are the smallest parts of your bodies, which work together and can form organ tissues in the body which, for example be muscle cells working in a muscle tissue.

Question 2

🟠 What are Tissues

Answer 2

A group of similar cells with similar structures and specialisations working together to help with the organ’s functioning.

Question 3

🟠 What are Organs

Answer 3

Organs are a group of several tissues which work together to perform specific functions. An example would be the stomach.

Question 4

🟠 What are Organ Systems

Answer 4

A multicellular organism is made up of a number of organ systems that work together to make it function specifically and ovally, while the organ systems are there to carry out specific functions

Question 5

🟠 What is an Organism

Answer 5

An organism is all of the cells, organs and organ systems working together to create a fully function living thing that can carry out different types of functions.

Question 6

🟢 What makes up the Digestive System?

Answer 6

-Mouth
-Oesophagus
-Stomach
-Stomach
-Liver
-Gall Bladder
-Pancreas
-Small Intestine
-Large Intestine
(Anus *included in Large Intestine)

Question 7

🟢 How does the Mouth digest food?

Answer 7

The teeth and the tongue are used to grind down the food and to release enzymes to break it down. The tongue releases these enzymes.

Question 8

🟢 How does the Oesophagus digest food?

Answer 8

The muscles in it’s wall help to keep the food moving downwards in a wave like contraction towards the stomach.

Question 9

🟢 How does the Stomach digest food?

Answer 9

The food comes through the sphincter, whilst the contractions of the thick walls helps to churn the food into chyme. It is also mixed with stomach acid to try and break down the proteins found in the food.

Question 10

🟢 How does the Liver digest food?

Answer 10

It produces bile which is stored in the gall bladder.

Question 11

🟢 How does the Gall Bladder digest food?

Answer 11

The bile produced in the liver is stored in the gallbladder. The bile travels along a bile duct and into the small intestine where it breaks up the fats into smaller droplets that can mix with watery liquids. (emulsification)

Question 12

🟢 How does the Pancreas digest food?

Answer 12

This secretes hormones which control glucose levels in your blood. When blood sugar drops, insulin secretion is replaced by glucagon which converts glycogen back into glucose.

Question 13

🟢 How do the Small Intestines digest food?

Answer 13

The food is kept moving through by peristalsis. Bile enters to duodenum after a meal and breaks up the fat in the food. Glands produce more enzymes to break down the foods even more.

Question 14

🟢 How does the Large Intestine digest food?

Answer 14

This is made up of the colon, appendix and the rectum. Here, the water is absorbed into the blood and the rest of the remains solidify. Now the faeces collect in the rectum and leaves through the anus.

Question 15

🟢 What is the difference between Organs and Organ Systems?

Answer 15

Organs and organ systems are very separate things in terms or their scale, but also inter-link with each other too. One of the differences between organs and organ systems are that organs include a collection of certain tissue in order to help it to function, however and organ system hold a collective set of organs that work together to help the organism function in a normal way. For example, the stomach (an organ) uses muscular tissue, glandular tissue and epithelial tissue, while the digestive system (an organ system) uses the mouth, oesophagus, stomach pancreas e.c.t instead. Further examples for an organ is the pancreas, with it’s tissues allowing it to make hormones and enzymes, with another example of an organ system being the circulatory system with the lung, heart and e.c.t.

Question 16

🟢 How do the Organs in the Organ Systems rely on each other?

Answer 16

For all of the organ systems to be performing at their upmost peak and in the regular way, each organ in the system relies on the others hugely for the process to run smoothly. This is very much the case in the digestive system too, as the mouth needs to chew and break down the food physically and chemically for it to be able to travel down the oesophagus. Moving on, if the oesophagus’s muscles aren’t relaxing and contracting, then the food will take an awfully long time to reach the stomach, therefore slowing down the process. The stomach working properly is vital because it needs to break down the large insoluble molecules that could not otherwise be digested as well further in the process. Furthermore, if the gall bladder, liver and pancreas were also out of use, then all the specific acids and hormones that need to be released wouldn’t be, which would also change the way of digestion. The small intestines, like the stomach, are also a vital part, as they also break down the insoluble molecules, but also absorb the nutrients from the faeces into the blood, using it’s villi; if this didn’t happen, then the body would not get the nutrients from the food at all. Lastly, the large intestines would have an impact on the digestive system because the water would not be absorbed out of the faeces, whilst the muscles would not shift the waste towards the rectum, which would pass it onto the anus to be excreted. This absolutely highlights the fact that each organ in the system relies on the other to function properly at all times .

Question 17

🟢 What are the 7 types of Nutrients?

Answer 17

• Carbohydrates (broken down into Simple Sugars by Carbohydrase) e.g Glucose and Sucrose
• Proteins (broken down into Amino Acids by Protease) e.g there are different amino acids that make up one longer protein chain.
• Fats (broken down into Fatty Acids + Glycerol by Lipase)
• Vitamins
• Minerals
• Water
• Fibre

Question 18

🟢 Why do you need Protein, Fats/Lipids, Carbohydrates and Fibre?

Answer 18

Protein - It is used for growth and repair of body tissues.

Fats/Lipids - It is needed for a protective layer over your body, whilst your body fat provides insulation.

Carbohydrates - Carbohydrates are your body’s main source of incoming energy, so it is important for having the energy to do everyday things.

Fibre - Helps bind cells together

Question 19

🟢 What are Enzymes?

Answer 19

In your body, the rate of chemical reactions is controlled by enzymes, which are special biological catalysts (each enzyme interacts with a particular substrate (reactant)

Enzymes are large protein. The shape of an enzyme is vital for the enzyme to function, as the long chains of amino acids are folded to produce a molecule with an active site that has a unique shape so it can bind to a specific substrate molecule.

Question 20

🟢 How do Enzymes react? (Equation)

Answer 20

Enzyme + Substrate Enzyme-reactant Complex Enzyme + Products

(+ Refer to GoodNotes diagrams and photos)

Question 21

🟢 How do Enzymes react? (Explanation)

Answer 21

The lock and key theory is a simple model of how enzymes work. The substrate of the reaction to be catalysed fits into the active site of the enzyme. The enzyme and the substrate bind together as the reaction takes place rapidly and the products are released from the surface of the enzyme.

(Remember that enzymes can join small molecules together as well as break up large ones.)

Question 22

🟠 What are Metabolic Reactions? (And what can they do?)

Answer 22

Enzymes control the metabolism, which is the sum of all the reactions in a cell or body. Different enzymes catalyse specific types of metabolic reactions:

• Building large molecules from lots of smaller ones. This includes building starch, glycogen or cellulose from glucose; lipids from fatty acids; or proteins from amino acids. Plant cells also combine carbon dioxide and water to make glucose, and use glucose and nitrate ions to make amino acids
• Changing one molecule into another. This includes changing one simple sugar into another, such as glucose to fructose, and converting one amino acid to another.
• Breaking down large molecules into smaller ones. This includes breaking down carbohydrates, lipids, and proteins into their constituent molecules during digestion; breaking down glucose in cellular respiration; and breaking down excess amino acids to form urea and other molecules that can be used in respiration.

Question 23

🟢 The Equation for Rate

Answer 23

Rate = 1 / Time

Question 24

🟠 Word and Chemical Equations for Hydrogen Peroxide reacting with Catalase Enzyme.

Answer 24

Word Equation:

Hydrogen Peroxide ————–> (Catalase Enzyme using piece of Liver) Water + Oxygen

Chemical (Balanced) Equation:

2 H202 ————–> (Catalase Enzyme using piece of Liver) 2 H2O + O2

Question 25

🟢 Digestive Enzymes and Products of Starch, Protein and Lipids + where they are in the Digestive System

Answer 25

Starch —> (Amylase) Glucose

• Carbohydrase Found in:
  
  • Mouth
  • Small Intestines

Protein —> (Protease) Amino Acids

• Found in:
  
  • Stomach
  • Small Intestine

Lipids —> (Lipase) Glycerol/Fatty Acids

• Found in:
  
  • Gall Bladder
  • Small Inestines

Question 26

🟠 How to test if Hydrogen Peroxide makes Water and Oxygen when it reacts with Catalase Enzyme

Answer 26

The Liver is put into the Hydrogen Peroxide, which means the Catalase Enzyme will work on chemically changing the Hydrogen Peroxide (2 H2P2) into Oxygen and Water (2 H2P + O2). You can see this happening as the bubbles rise to the top with the water.

To test if it is has oxygen in it, you can burn a splint, then blow it out and put it in the substance, and if there is oxygen, it will relight.

Question 27

🟢 What Is Bile?

Answer 27

Bile is a green/yellow liquid made in the liver and stored in the gall bladder. Bile is squirted onto the food through the bile duct. It is alkaline to neutralise hydrochloric acid from the stomach (to neutralise the pH levels). It also emulsifies fat to form small droplets which increases the surface area (while the volume is kept the same). The alkaline conditions and large surface area increase the rate of fat breakdown by lipase.

However, one downside is that gall stone can form, blocking the bladder. This happens when the bile crystallises and can prevent bile from going to the small intestines. They can cause terrible pains and can range from a few millimetres to a couple centimetres wide.

Question 28

🟢 Where is Bile Produced, Stored and Released?

Answer 28

Produced:
Bile is produced in the liver and then stored in the gall bladder, before it is sent to the small intestines to break up the fats.

Stored:
Bile is produced in the liver and then stored inside of the gall bladder.

Released:
The Bile is released into the small intestines on the food.

Question 29

🟠 Enzyme Notes:

Not Really Needed

Answer 29

Enzymes are biological catalysts - they speed up the chemical reactions that take place inside all cells, but without being used up in the process.

Enzymes are protein molecules, and so are made up of amino acids. Most enzymes contain between 100 and 1,000 amino acids.

Enzymes are very specific about which reactions they catalyse. Only molecules with exactly the right shape will bind to the enzyme.

The long chains of amino acids are folded to produce a molecule with an active site that has a totally unique shape so it can bind to a specific substrate model.

A substrate fits into an enzyme in the way a lock fits into a key, which is why a substrate is though to fit through into an enzyme’s active site. The enzyme is the lock and the reactant is the key.

Enzymes control the metabolism in your body - the sum of all the reactions the the cell or body. Each of your cells can have a hundred or more chmeical reactions going on within it at any one time. Enzymes deliver the control that makes it possible for your cell chemistry to work without one reaction interfering with another.

Question 30

🟠 What is an Independent Variable

Answer 30

An Independent Variable is the variable that is altered during a scientific experiment.

Question 31

🟠 What is a Dependant Variable

Answer 31

A Dependant Variable is the variable being tested or measured during a scientific experiment

Question 32

🟠 What is a Control Variable

Answer 32

A Control Variable is the variable that is kept the same during a scientific experiment.

Question 33

🟠 What 3 Layers line the stomach

Answer 33

The inner-most layer that lines the stomach is the epithelial and glandular tissue

The second layer is the layer is the eplithelial layer containing blood vessels

The third and final layer that lines the stomach are the muscle layers