U2 B2 2HVTTO

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

B2 The digestive system

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

       Laptop/Book

       Notebook, pencil case

• Bag on the floor
  
• Read pages 97-99

Lessongoals

• You can describe the functions of digestion, digestive juices and enzymes
  
• You can list parts of your dentition and their functions
  
• You can describe the function of peristalsis an how it works

Homework U2 B2

Asgmt 1-8, 4c

OR challenge

Asgmt 3, 5-10

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

Scan the chapter

Use your book and laptop/notebook

• Go to Unit 2 Basics 2 on pages 97-99
• Quickly scan the text for difficult/unknown words
• Make a list of all the words you don't know/understand, add these to your PIF
• Add descriptions and/or synonyms of these words during the lesson

Which of these statements is FALSE

1. Fruit contains lots of vitamins
2. Vitamins can be used as building material for the body
3. Vitamins help protect your body
4. Vitamins can be used as reserves

Which of these statements is TRUE ?

1. Foodstuffs are in nutrients
2. Foodstuffs and nutrients are synonymous
3. Nutrients are in foodstuffs

Which of these statements is FALSE

1. All carbohydrates are sugars
2. Carbohydrates can be used as building materials
3. Carbohydrates can make people fat
4. Carbohydrates can be used as fuels

Too big to take in, needs digestion

• Proteins
• (most) carbohydrates
• Fats

No digestion needed:

• Glucose
• Minerals
• Vitamins
• Water

Intestines take up the nutrients inside food.

Not all nutrients can enter the body without digestion

Digestion

• Digestion = breaking nutrients into smaller substances (so they can enter the body)
• Mechanical       and chemical       digestion
• Chewing and digestive juices

Mechanical = using movements

Chemical = using substances

Why chew?

Digestive juices need to digest nutrients

Chewing makes the surface area of our food bigger

You've got a cube of 1x1x1 cm. What is the surface area of this cube??
...... cm2 (number)

The cube of 1x1x1 cm is cut in to 8 similar sized smaller cubes of 0,5x0,5x0,5 cm.
What is the surface area of one of these cubes?
..... cm2 (number)

How big is the surface area of the 8 cubes together?
....cm2 (number)

Why chew?

Chewing creates a bigger surface area.

bigger surface area = more surface where digestive juices can do their job = more and quicker digestion

surface area of 6 cm2 

(if it were a cube of 1x1x1 cm)

surface area of 1,5 cm2

together 12 cm2

Dentition (all teeth together)

Crown

Root

incisor             canine                        molar

cutting off parts of food

cutting off pieces of food

grabbing on to food (mainly used by predators when capturing their prey)

grinding food down into smaller pieces

Digestive juices

• Digestive glands: salivary gl, gastric gl, liver, pancreas, intestinal gl
• Nutrients > digestion products
• Often contain enzymes

The picture shows how an enzyme (the arrowlike shape) breaks down a nutrient (the long chain) into smaller subtances

Gland = an organ that makes substances

Enzymes are specialized substances that break down other subtances.

Every enzyme fits in/on a specific substance. It will then break this substance into smaller pieces (help digest it)

Peristalsis

Food moves through lots of tubes : intestinal tract

• Oesophagus
• Duodenum
• Small and large intestines

peristalsis = muscle movements that 

push food through the intestinal tract

Here you can see the peristalsis happening in your oesophagus.

Muscles in the oesophagus contract and relax allowing it to push food towards your stomach.

These movements are strong enough to allow you to eat/drink upside down.

00:00

Darmperistaltiek

Eten gaat door allerlei 'buizen'

• Slokdarm
• Dunne darm
• Dikke darm

Darmperistaltiek = spierbewegingen die eten door de darmen heen duwen

00:06-00:16

Peristalsis of the large intestine

What nutrients is NOT digested?

1. Water
2. Fat
3. Carbohydrate
4. Protein

Chewing your food is part of
.... digestion

1. Mechanical
2. Motor
3. Chemical
4. Chew

What you should do: U2 B2

• Pages  97-103
• Asgmt  1-8, 4c

OR challenge

• Asgmt 3, 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 B2

• Pages 97-103
• Asgmt 1-8, 4c

OR challenge

• Asgmt 3, 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

Tidy Duty

3 people each lesson

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