YR2-K4-LSN8

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

HAVE READY:

- JOIN THIS LESSONUP

- KERBOODLE PAGE 54

- YOUR NOTEBOOK

- GOOGLE CLASSROOM

LESSON 8: Chemical digestion and absorbtion

TODAY'S LEARNING GOALS:

• I have a good knowledge and understanding of the enzymes and their workings.
• I know how our body absorbs nutrients and where the various nutrients get absorbed.

TODAY'S KEY WORDS:

• Amylase 
• Protease 
• Lipase 
• Fatty acids
• Glycerol 
• Saliva 
• Mucus
• Renin
• Bile

read kerboodle pages 54-58

CHEMICAL DIGESTION:

• breaking down polymeric nutrients that cannot be absorbed into monomeric molecules
• by enzymes

Enzymes:

• speeds up chemical processes
• reaction specific
• sensitive to temperature and acidity
• substrate: molecule that goes into the molecule
• product(s): molecules that go out of the enzyme

Digesting carbohydrates

• ORAL CAVITY and DUODENUM amylase: cuts starch into maltose
• SMALL INTESTINE: maltase: cuts maltose into glucose
• SMALL INTESTINE lactase: cuts lactose into galactose and glucose

A person that is lactose intolerant cannot produce (enough) lactase.
Explain what happens to a person that is lactose intolerant.

Digesting peptides (proteins)

• STOMACH: pepsin: cuts proteins into peptide fragments
• DUODENUM: trypsin: cuts peptide fragments into smaller fragments
• SMALL INTESTINE peptidases: cuts small peptide fragments into amino acids

Digesting carbohydrates

• ORAL CAVITY and DUODENUM amylase: cuts starch into maltose
• SMALL INTESTINE: maltase: cuts maltose into glucose
• SMALL INTESTINE lactase: cuts lactose into galactose and glucose

Enzymes are very sensitive to acidity.
1. Explain why amylase added by the salivary glands stops working when it reaches the stomach.
2. Explain why the pancreas produces more amylase.

Digesting lipids (fats)

• DUODENUM: lipase: cuts fats into glycerol and fatty acids

Fats and water don't mix
Explain how bile increases lipase efficiency

Digesting carbohydrates

• ORAL CAVITY and DUODENUM amylase: cuts starch into maltose
• SMALL INTESTINE: maltase: cuts maltose into glucose
• SMALL INTESTINE lactase: cuts lactose into galactose and glucose

Nutrient absorption

• Small intestine and lesser extent: large intestine.
• Large surface area
• More surface means more absorption
• Folds, villi, microvilli
• 30 m2 of total surface area

IMPORTANT DATES

• Lesson 9: next week
• practice test: grade 2x in magister
• lesson 10: two weeks from now
• FINAL test: on paper in class

HW FOR LESSON 9

• COMPLETE THE IN CLASS ASSIGNMENTS FOR LESSON 7 (PART 2)
• PREPARE FOR THE REVIEW LESSON (READ ALL NOTES AND EXERCISES, BE PREPARED TO ASK ME QUESTIONS AND BE PREPARED FOR A PRACTICE TEST OF SOME KIND)
• MAKE SURE YOU WRITE DOWN YOUR SUMMARIES OF THE DAY 
• MAKE A PLAN AND DECIDE IF YOU ARE DOING THE GLOSSARY QUIZ AND OR THE SUMMARY FOR A GRADE.
• WORK ON YOUR PROJECT