gas exchange and respiration

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

gas exchange and respiration

1.2 - Gas exchange and respiration

Today's schedule

• Goals and Important concepts
• What is air?
• Respiration and gas exchange
• Diffusion
• Osmosis
• Work time
• Feedback

Goals and Important concepts

Important concepts

• Cellular Respiration
• Lung capillaries
• Diffusion
• Osmosis

Goals

• Understand what air is.
• Understand what happens during gas exchange.
• Understand what diffusion and osmosis are

What is air?

Air is a mixture of gasses

We use 4% of oxygen from the air, and produce 100x as much carbon dioxide.

But where does the water come from?

Respiration and gas exchange

Cells need energy. How do they get this energy?

Cells burn glucose + oxygen to produce energy. 

Secondary products = water + carbon dioxide = waste products.

Cellular Respiration = the process where cells break down glucose for energy.

Photosynthesis is the opposite of respiration, producing oxygen and glucose as waste products

Fill in the blanks;
The formula for cellular respiration is:
glucose + [1] --> Water vapor + [2] + E

1. 1 = Carbon Dioxide 2 = Oxygen
2. 1 = Oxygen 2 = Carbon Dioxide

Carbon dioxide and water need to leave your body, and oxygen needs to enter. How and where?

In the alveoli through small blood vessels (= lung capillaries). Capillaries connect to veins to transport throughout the body.

Carbon dioxide in blood > in alveoli. 

Oxygen in blood < in alveoli.

How do these gasses exchange between blood and alveoli?

Diffusion

Diffusion is one of the most important processes in our body. based on the movement of particles. 

Diffusion = the movement of particles from an area of high concentration to an area of low concentration, until they become equal.

If Carbon dioxide concentration in alveoli is lower than in the blood, it moves from the blood to the alveoli until the concentrations are equal.

Fill in the blanks:
The concentration of Oxygen is [1] in the blood and [2] in the alveoli. Thus Oxygen moves out of the alveoli.

1. 1 = high 2 = low
2. 1 = low 2 = high

Osmosis

What about water?

Water moves similar to diffusion, through a cell's membrane. Osmosis = the diffusion of water from a higher concentration to a lower concentration. Direction depends on other particle concentrations.

  1. Cells produce water particle 

  2. concentrations in cells become lower then outside cells.

  3. water moves through cell's membrane into blood 

  4. excess water diffuses out of the avioli as water vapor.

Work time

What? Questions 9, 10, 13, 14, 17, 18 & 19

Why? To test your knowledge of the concepts.

How? Alone in silence, or whispering when discussing with your neighbour

Help? First read your textbook, then ask your neighbour, finally ask me.

Time? 15 minutes.

Done? See if neighbours need help, or read and learn pages 13 - 17

Feedback 

Fill in the post-its I gave you with the following information:

- What did you think of this lesson?

- What did I do good?

- What could I do better?

I want feedback from everyone.