Respiration and Gas Exchange

Question 1

What is respiration?

Answer 1

the process of releasing energy from glucose, which happens constantly in every cell

Question 2

When does aerobic respiration occur?

Answer 2

When there’s plenty of oxygen available

Question 3

When does anaerobic respiration occur in humans?

Answer 3

When you do really vigorous excursive and your body can’t supply enough oxygen for aerobic respiration

Question 4

What is the equation of aerobic respiration?

Answer 4

Glucose + Oxygen = Carbon Dioxide + Water (+ Energy)

C6H12O6 + 6OO2 = 6CO2 +6H2O (+ Energy)

Question 5

What is the word equation for anaerobic respiration in humans?

Answer 5

Glucose = Lactic Acid (+ Energy)

Question 6

Can plants respire without oxygen too?

Answer 6

YES

Question 7

What do plants produce when they respire anaerobically?

And what is the word equation?

Answer 7

ethanol and carbon dioxide

Glucose = Ethanol + Carbon Dioxide (+ Energy)

Question 8

How do plants exchange gases?

Answer 8

By diffusion

Question 9

How are leaves adapted for efficient gas exchange?

Answer 9

They are broad - large surface area for diffusion
They are thin - short distance for gases
There are air spaces inside
Lower surface full of stomata

Question 10

What are the opening and closing of stomata controlled by?

Answer 10

the cells that surround them (guard cells)

Question 11

Where are the lungs situated?

Answer 11

In the thorax (top part of body)

Question 12

What separates the thorax from the rest of the body?

Answer 12

The diaphragm

Question 13

What are the lungs protected by?

Answer 13

The ribcage

Question 14

What is the ribcage surrounded by?

Answer 14

the pleural membranes

Question 15

How does air go into your lungs?

Answer 15

Down the trachea, splits into two bronchi, splits into bronchioles, end at alveoli.

Question 16

Where does the actual gas exchange take place?

Answer 16

In the alveoli

Question 17

What happens when you breathe in?

Answer 17

Intercostal muscles and diaphragm contract
Thorax volume increases
This decreases the pressure, drawing air in

Question 18

What happens when you breathe out?

Answer 18

Intercostal muscles and diaphragm relax
Thorax volume decreases
Air is forced out

Question 19

How can you investigate the effect of exercise?

Answer 19

On breathing rate

Question 20

Why does exercise increase breathing rate?

Answer 20

Your muscles respire more during exercise and need to be supplies with more O2 and have more CO2 removed

Question 21

How many alveoli are there in the lungs?

Answer 21

millions

Question 22

How are alveoli adapted for sufficient gas exchange?

Answer 22

• They have a large surface area
• Moist lining - for gases to dissolve in
• Thin walls ( one cell thick) - short diffusion distances between air and blood
• Great blood supply - maintain a high conc. gradient
• Walls are permeable

Question 23

How does smoking lead to emphysema?

Answer 23

Damages walls inside the alveoli, reducing surface area for gas exchange

Question 24

What does the tar in cigarettes damage?

Answer 24

The cilia in your lungs and trachea
They catch dust and bacteria before they reach the lungs and help keep trachea clear by sweeping mucus back towards the mouth
When cilia are damaged, chest infections are more likely

Question 25

What does tar irritate?

Answer 25

The bronchi and bronchioles, encouraging mucus to be produced, which can’t be cleared well, causes smokers cough and chronic bronchitis

Question 26

What does the carbon monoxide in cigarettes cause?

Answer 26

It reduces the amount of oxygen the blood can carry.
to make up for this, heart rate increases - can lead to high blood pressure
high blood pressure damages artery walls, increasing risk of blood clots and coronary heart disease

Question 27

What in cigarettes, are chemicals that can lead to cancer?

Answer 27

carcinogens