U2 B5 2HVTTO

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 2

B5 Food spoilage

• Jacket in your locker
• Put your things on your desk

       Laptop/Book

       Notebook, pencil case

• Bag on the floor
  
• Read pages 125-127

Lessongoals

• You can describe ways to prevent food spoilage

Homework U2 B5

Asgmt 1-8, 4c

OR challenge

Asgmt 5-10

Secret Student

This lesson, I have randomly picked someone to be the secret student.

I pay special attention to:

• Your use of English
• Your participation in the lesson

At the end I will reveal the secret student, If I can give them positive feedback, they also earn 1/3 +0,5 OR +1 cm² cheat sheet.

Wheel of homework

Go to Lessonup.app and use this code

Reward

Penalty

Rewards

• +1 cm2 cheatsheet = you get to make a cheatsheet for a test. This starts being 1 by 1 cm. Everytime you earn this it gets 1 cm bigger to a max of 4 by 4 cm.
• 1/3 +0.5 = If you earn this 3 times you get to add 0,5 to one of your biology marks.
• Snitch = You can pick a classmate who also is checked for homework, you earn two V's (having 3 earns you a 1/3 +0,5)
• Too bad = You only get one V
  

penalties

• 45 min extra worktime = you need to come after school and do homework, this will last for 45 min or until the task is done
• Coloringpage = You get to pick a coloringpage, You need to color it and perform tasks that might be on it. You need to hand it in during the next lesson, If you don't you get 2 marks.
• 2/1 marks = a mark is an X, if you get 3 of these you will automaticly earn the 45 min extra worktime.
• Snitch = You can pick a classmate who also is checked for homework
• Lucky! = You don't get a penalty

Clara is an adult woman.
She calculates her BMI.
How should she do that?

1. BMI=​weight​2​​​​length​​
2. BMI=​lenght​2​​​​weight​​
3. BMI=​weight​​length2​​
4. BMI=​length​​weight​2​​​​

Her BMI turns out to be 23,5.
What does this mean for her?

1. Her weight is too low
2. Her weight is healthy
3. Her weight is too high
4. Her weight is way too high

A certain foodstuff contains 20 kJ of energy.
How much J is that?

1. 2.000 J
2. 20.000 J
3. 0,002 J
4. 0,02 J

Meyra en Miray are identical twins.
The amount of energy they need is not the same.
What is the most logical reason for this difference?

1. Their sex is different
2. Their height is different
3. Their age is different
4. Their physical activity is different

Why does food spoil?

What happens when you eat/drink spoiled food?

Food spoilage

Bacteria and fungi eat our food = food spoilage

They need:

• Food
• Moisture
• Right temperature
• Right environment

Preserving food is done by changing these things: 

Making it impossible/hard to live on the food for bacteria/fungi

Preserving - Water

• Drying

             Bacteria/fungi dry out

Preserving - Cooling

• Fridge > 3 - 4 °C

            Bacteria/fungi are slowed

• Deep freeze > -20 °C

            Bacteria/fungi are frozen

Preserving - heating

• Pasteurization > 72 °C

           Most bacteria/fungi are killed

• Sterilization >130 - 140 °C

            Bacteria/fungi are killed

Preserving - Additives

• Preservatives 

           Sugar                   Acid

           Salt                       Sulphite

           Vinegar

• Additives

            Colourings       Aromas

            Flavourings

Preserving - other ways

• Irradiation

             Bacteria/fungi are killed with radioactive rays

• Inert packing

             Adding a mixture of gases to the packaging helps the food stay fresh                 longer

• Vacuum packing

            After pasteurization/sterilization/preservatives/inert packing

           Bacteria/fungi are unable to reach the food

What you should do: U2 B5

• Pages 125-131
• Asgmt  1-8, 4c

OR challenge

• Asgmt 5-10

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zs = Working in Silence

• No asking questions
• Silent, don't disturb anyone
  
• Stay at your  desk

What you should do: U2 B5

• Pages 125-131
• Asgmt 1-8, 4c

OR challenge

• Asgmt 5-10

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zw = Working with whispering

• Teacher is available for questions
• Only whisper with the student next to you
• Stay at your  desk

Secret Student

The secret student was .......

I paid special attention to:

• Your use of English
• Your participation in the lesson

If I can give them positive feedback, 

they also earn 1/3 +0,5 OR +1 cm² cheat sheet.

Tidy Duty

3 people each lesson

• Desks: empty and straight
• Chairs:  underneath the desks OR end of day: on the desks
• Floor: no rubbish