Organisation - Cells & Organs / Digestive enzymes and System / Heart / Lungs

Question 1

Put the following in order from smallest to biggest:
* Organs
* Tissues
* Cells
* Organ system

Answer 1

• Cells
• Tissues
• Organs
• Organ system

Question 2

Define tissue

Answer 2

A group of similiar cells that work together to carry out a particular function; can also include one or more type of cell.

Question 3

What does the following tissues do:
* Mascular tissue
* Grandular tissue
* Epithelial tissue

Answer 3

• Mascular tissue - contracts to move whatever is attached to it.
• Grandular tissue - makes and secretes chemicals like enzymes and hormones.
• Epithelial tissue - covers some part of the body such as the inside of the gut which helps to protect the stomach from harsh acidic environment.

Question 4

Define organs

Answer 4

A group of different tissues that work together to perform a certain function.

Question 5

What do the following tissues do in the organ stomach:
* Mascular tissue
* Grandular tissue
* Epithelial tissue

Answer 5

• Mascular tissue - moves the stomach wall to churn up the food
• Grandular tissue - makes digestive juices to digest food
• Epithelial tissue - covers the outside and inside of the stomach.

Question 6

Define organ system

Answer 6

A group of organs working together to perform a particular function.

Question 7

The digestive system breaks down and absorbs food and what do the following organs do:
* Glands
* Stomach and small intestine
* Liver
* Large intestine

Answer 7

• Glands - (pancreas and salivary glands) produces digestive juices
• Stomach and small intestine - digest food; small intestines also absorb soluble food molecules
• Liver - produces bile
• Large intestine - absorbs water from the undigested food. leaving faeces (the waste that remains after food has been digested and its nutrients absorbed by the body)

Question 8

What are enzymes? (5)

Answer 8

• They are biological catalysts
• That speed up the chemical reaction in the body.
• They don’t change the overall reaction but only makes it faster
• They are not used up in the reactions.
• They are large proteins

Question 9

What is a catalyst?

Answer 9

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

Question 10

Explain how enzymes get catalysed?
(The collision theory)

Answer 10

A collision must occur with sufficient energy and in a specific orientation for a reaction to occur.

• The enzymes have an active site (where the reaction occurs) that needs to match and fit into the shape of the active site with a specific substrate. They fit together like a lock and key mechanism.
• Once the substrate is in the active site, reaction occurs and after the reaction, the enzymes releases the substrate and carries on moving to find the next substrate
• The enzymes break down the substrate into two smaller products but the enzyme doesn’t change as it doesn’t get used up.

Question 11

How does the pH and the temperature affect the enzyme reaction?

Answer 11

Temperature and pH of the enzymes are the optimus.

• pH affects the enzymes as they are sensitive to it. If its too high or low, the pH interferes with the bond holding the enzymes together which changes the shape of the active site and denatures the enzyme. Alternatively, the rise in temperature can make the enzymes molecules vibrate more, increasing the rate of reaction.
• As the temperature increases, the rate of reaction increases as the enzymes and substrate gain more sufficient energy, meaning they are more likely to collide with each other and reaction will take place. Alternatively, if it gets too hot, the bonds holding the enzyme together breaks and the active site changes and substrate won’t fit anymore. This shows that the enzyme has denatured.

Question 12

What is the role of the digestive system?

Answer 12

To break down large molecules into smaller (soluble) molecules so they can pass through the walls of digestive system easily, and be absorbed into the bloodstream.

Question 13

1) Which enzyme breaks down carbohydrates? What does it break into?
2) From where is the enzyme secreted? (3)

Answer 13

1) Amylase (example of the enzyme carbohydrase) breaks down chemical bonds between the individual sugar molecules in each carbohydrate chains; breaking the starch down into maltose and glucose.
2) it is secreted by:
* salivary glands
* pacreas
* small intestine

Question 14

1) Which enzyme breaks down proteins? What does it break into?
2) From where is the enzyme secreted? (3)

Answer 14

1) Protease breaks down proteins into amino acids; as proteins are made up of amino acids.

2) It’s secreted by:
* stomach (pepsin)
* pancreas
* small intestine

Question 15

1) Which enzyme breaks down fats? What does it break into?
2) What helps the fat to mix with water?
3) From where is the enzyme secreted? (2)

Answer 15

1) Lipase breaks down fats (lipids) into glycerol and fatty acids.
2) Emulsification occurs - when bile allows fat to mix with water by breaking fats into smaller droplets.

3) It’s secreted in:
* pancreas
* small intestine

Question 16

What do the salivary glands produce and where?

Answer 16

Produce amylase enzymes in the saliva.

Question 17

1) What does the stomach do with its walls?
2) Which enzymes does stomach produces?
3) Why does the stomach produce hydrochloric acid? (2)

Pummels - forcefully breaking it down or crushing it.

Answer 17

1) It pummels the food with its mascular walls to digest the proteins with the pepsin.

2) It produces proteases and pepsin enzymes.

3) Hydrochloric acid kills bacteria and gives the** right pH of 2 (which is acidic) for the protease** enzyme to work.

Pummels - forcefully breaking it down or crushing it.

Question 18

What is the role of liver in digestive system?

Answer 18

It produces bile as it neutralises the stomach acid and emulifies fats.

Question 19

What’s the role of gall bladder in the digestive system?

Answer 19

It stores the bile, before its released into the small intestines.

Question 20

1) Which emzymes does the pancreas produce?
2) Where are the enzymes released to?

Answer 20

1) It produces protease, amylase and lipase enzymes.
2) They are released into the small intestines.

Question 21

What is the role of large intestine in the digestive system?

Answer 21

It absorbs the excess water from the food.

Question 22

1) What is the role of small intestines in the digestive system?
2) Where does the digested food from the digestive system go to?

Answer 22

1) It produces protease, lipase and amylase to complete the digestion.

2) In small intestines, the digested food absorbed out of the digestive system and into the blood.

Question 23

What is the role of rectum in the digestive system?

Answer 23

This the where the faeces are stored which is mainly made up of indigestible food, before they are released through the anus.

Question 24

Label the thorax diagram

https://quizlet.com/gb/289172708/gcse-biology-topic-2-set-5-thorax-diagram/

Question 25

Write the word and symbol equation of respiration.

Answer 25

Oxygen + glucose = Carbon dioxide + Water + Energy
6 O2 + C6H12O6 = 6CO2 + 6H2O + ATP

Question 26

1) What are the little air sacs called in the lungs?
2) What are they surrounded by?

Answer 26

1) The air sacs are called the alveoli.
2) The alveoli are surrounded by blood capillaries.

Question 27

Name 3 features of the alveoli that helps with gas exchange. (5)

Answer 27

• Large surface area; allows more space for the gas exchange of oxygen and carbon dioxide.
• Very thin walls; provides a short diffusion pathway for the gas exchange
• Moist lining; allowing gases to dissolve which allows them to diffuse across the lining
• Good blood supply; allows gas exchange to happen at a faster rate.
• Good ventilation; provides good supply of air. (only state this one if you can’t remember the other 4 above)

Question 28

Write the formula to calculate Breaths per minute.

Answer 28

Number of breaths ÷ number of minutes

Question 29

What are the 3 things that the cirulatory system consists of?

Answer 29

1) Heart
2) Blood vessels
3) Blood

Question 30

What does it mean by double circulatory system?

Answer 30

It has two circuits joined together.
* The right ventricle pumps deoxygented blood to the lungs for it can take in oxygen and then it returns to the heart.
* The left ventricle pumps oxygenated blood around all the other organs of the body. The blood tranfers its oxygen to the body cells and deoxygenated blood returns back to the heart to be pumped out the lungs again.

Question 31

What is the role of valves in the heart?

Answer 31

They ensure the blood flow is in the right direction; they prevent it flowing backwards.

Question 32

Describe the blood flow in the heart through the 4 chambers.

Answer 32

• Blood flows into the two atria from the vena cava and the pulmonary vein.
• The atria contracts, pushing the blood into the ventricles.
• The ventricles contract, forcing the blood into the pulmonary artery and the aorta, and out of the heart.
• Then the blood flows to the organs through arteries and returns through the veins.
• The atria fills again and the cycle repeats.

Question 33

How does the heart gets its own supply of oxygenated blood when it needs it?

Answer 33

Coronary arteries branch off the aorta and surround the heart, which makes sure that it gets all the oxygenated blood it needs.

Question 34

1) Where is the pacemaker in the heart?
2) What is produced to make the muscle cells contract?

Answer 34

1) The pacemaker is in the right atrium, in which it has group of cells that control the heart rate.
2) These cells produce electric impluses that spread to the surrounding muscle cells, causing them to contract.

Question 35

Why is an artificial pacemaker used?
How is it implanted in the body?

Answer 35

To control the heartbeat if the natural pacemaker doesn’t work properly ; if the patient has irregular heartbeat.

It’s a little device implanted under the skin and has a wire going to the heart, which produces electric current to keep the heart beating regularly and normally.