ebook chapter 9 nutrition and digestive system

Author & Editor
Nurnisrina Binti Mohd Ayoob

2020949517

Learns Smart with

LOTS HOTS
ITEMS

TEXTBOOK
ALLIGNED

I-THINK

VISUAL
MINDMAP

Special Features 21ST CENTURY
LEARNING
✓ Presents Facts, Concepts, Idea And
Essential Notes DSKP
ALIGNED
✓ Encourages HOLISTIC learning and
stimulates the mind by correlating
facts and information

BioEdu Publication SDN.BHD

Exclusive Features Of This Book

Acronym for you Formulate an Acronym for
(MSDS LA) student to remember

M – Mouth Provide a QR code for
S – Stomach information on video or from
D- Duodenum
S- Small Intestine websites to help students
L – Large Intestine understand a topic
A – Anus
Visual i-THINK that is colourful
Scan to view and simple to help student
internal understand the concept

structure of
ileum

i-Think

Try This An interactive quiz on Quizizz
for student to challenge

themselves based on the topic

Summative Evaluation Provide LOTS and HOTS
items based on latest SPM

format

Content i
i
Preface ii
The Author iii
Introduction
Learning Objectives

1. Digestive System 1-3
Digestion 3-4
Absorption
Assimilation 5
Defaecation 6
2. Balanced Diet
Diet modifications for specific individuals 7
3. Health Issues Related to the Digestive
System and Eating Habits 7
The effects of modifying digestive organs on
human health 8
Health issues related to defaecation 9
Health issues related to eating habits 10
Summative Evaluation 11-12
References

Preface

This Smart Bio Lesson Book is a product of improvement efforts in the teaching
and learning of students and teachers. The preparation of content is also in
accordance with the learning standards set by the Curriculum Development Division
(BPK) and in accordance with the Curriculum and assessment standards document
(DSKP).

This lesson book prepares students to understand the concepts in topic 9 Nutrition
and Human Digestive System in Biology of Form 4. This book contains three main
subtopics that cover the entire topic in the textbook learning standards. The uses
of graphic presentation along with QR code feature make it easy for students to
search for information on their own. This encourages students in self-directed
learning.

Indeed, the publication of this lesson book is a new exploration to the author who is
a student majoring in teaching. The publication of this book to some extent
provides beneficial knowledge to the author in the future. The author is sincerely
ready to accept criticism for further improvement of this book in the future in line
with the teaching and learning of the 21st century.

The Author

Nurnisrina Binti Mohd Ayoob

(2020949517)

UNIVERISITI TEKNOLOGI MARA (UiTM)
PUNCAK ALAM

(2020-CUURENT)
Second Semester student of Bachelor’s
Degree in Education Science (Hons.) Biology

Introduction

The topic of Nutrition and Human Digestive System is considered a difficult topic
amongst the students and teachers. According to a research on “Difficult topics in
Biology from the viewpoint of students and teachers based on KBSM
implementation” conducted by Salleh, Ahmad and Setyaningsih in 2021, the topic
of Nutrition (previously combined with digestive system in human) is the second
highest difficult topic after Cell Division which was supported by 21 students
(6.0%) and 3 teachers (4.2%). In their research, the topics with lowest mean value
was considered as the most difficult. Unfortunately, the topic of Nutrition was
identified as the most difficult for students because the mean score value was
the lowest compared to other topics (M = 2.95, SD = .933). From the research, the
factors addressing the difficulties of the topics are due to the concepts that are
too abstract (15.2%), concepts that are difficult to understand (18.2%) and
various terms that are difficult to describe (57.6%) and others (9.1%). In another
literature, the findings show that the subjects and concepts perceived to be
difficult to learn by the pre-service teachers is on topic digestive system is 2.5%.
this is because the subjects and concepts perceived to be difficult to learn and
teach overlap to a great extent (Gungor and Ozkan, 2017).

Since the topic Nutrition and Human Digestive System (KSSM syllabuses) is really
associated with abstract concepts that are indescribable and cannot be visualized.
We emphasis on this book that will help students with all type of learners,
especially the Visual Learners and Auditory Learners. Visual learners are the
learners who is better at learning with visual elements such as videos, images, and
demonstration. As for Auditory Learners are the learners that best learns with
the help of audio elements such as lectures, recording, and verbalizing lessons. We
also take into account for Kinaesthetic Learners who is best learning with aid of
hands-on activity, trial-and-error and problems-solving activities. All in all, this
lesson book is suits for all type of learners in normal academic schools in Malaysia.

Learning Objectives

After go through this lesson book, student should be able to:

1. Digestive system

▪ List SIX (6) organs involved in alimentary canal
▪ Describe TWO (2) types of digestion in humans

2. Digestion

▪ Explain ONE (1) product of carbohydrate digestion in mouth
▪ State THREE (3) adaptation of epithelial cells of the stomach that involved in

digestion of protein
▪ Describe the digestion of carbohydrates, proteins and lipid in the duodenum

and ileum including the types of enzymes involved

3. Absorption

▪ Identify TWO (2) important the structure of villus that involved in
transportation of absorbed nutrient

▪ Discuss THREE (3) adaptation of villus for better absorption of nutrient in
ileum.

4. Assimilation

▪ Discuss FOUR (4) function of liver in assimilation of digested food

5. Defaecation

▪ Explain the process of absorption of water and vitamins in large intestine
▪ Explain the formation of faeces in large intestine

6. Balanced Diet

▪ Justify the modification of diets for obesity and diabetes mellitus patient

7. Health Issues related to Digestive Systems and Eating Habits

▪ Analyse the (1) effect of gastric bypass on human health in terms of
advantages, disadvantages, long-term effect and short-term effect

▪ Outline FOUR (4) health issues related to defaecation problems
▪ Briefly describe THREE (3) health issues related to eating habits including the

symptoms, factors and health risks.

1. Digestive System Structure of Human Digestive System

Salivary glands

Mouth Spleen
Oesophagus

Gall bladder Stomach

Duodenum Pancreas

Small Jejunum Colon
Intestine Ileum Caecum

Large
Intestine

Rectum

Anus
Diagram 1 Structure of human digestive system

Digestion Physical Digestion:
Involves mechanical action of teeth to increase
Chemical Digestion: the surface are for enzyme reaction and
Involves enzyme reaction alongside the digestive tracts, peristalsis action
starting in mouth, in stomach and part of the intestine.

Salivary Teeth
Glands While chewing, the teeth will break
down the food with the help of the
The presence of food in the tongue into smaller particles
mouth will stimulate the
salivary glands to secrete Oral cavity
saliva

Diagram 2 Structure in upper level of alimentary canal

Mouth Digestion of Carbohydrate 5 main components of saliva:
Water = moisten and softens the food
• Involved Salivary glands Lysozyme = kills bacteria
• Secretion: Saliva (pH 7) Sodium salt = prepares an alkaline medium
• The presence of food stimulates salivary glands Mucus = lubricates the food
Salivary amylase = hydrolyses starch and glycogen
to secret saliva to moisten the food.
• Saliva contains a Salivary amylase enzyme that

breaks down starch into maltose.
• Starch + water salivary amylase maltose

Esophagus Peristalsis Action Bolus Mucus secretion on the
esophageal wall helps move
• Saliva in mouth helps in formation of bolus to the bolus all the way to the
enter the esophagus stomach

• Rhythmic contraction and relaxation of esophagus Diagram 3 Peristalsis action
wall's muscles pushes down the food bolus into
stomach.

• No digestion occurs

Stomach Digestion of Protein Mucous cell
Secretes mucus
Involved Gastric glands (adaptation of epithelial cell)
Secretion: Gastric juice Parietal cell
Gastric juice contains: Releases HCL
- Rennin (coagulates milk )
▪ Soluble protein (Caseinogen) rennin Insoluble milk Chief cell
Releases pepsinogen
protein (Casein)
- Pepsin (active form) Diagram 4 Structures of stomach lining wall
▪ aid in the hydrolysis of protein
protein + water polypeptides pepsin polypeptides
- Hydrochloric acid (HCL)
▪ To kill the bacteria from the food
▪ Act as an acidic medium for the action of pepsin

and rennin
▪ Stop the activity of salivary amylase

Duodenum Lipid Emulsification Liver
Synthesises of bile

Digestion of Carbohydrate, Protein, Lipid

▪ Secretion of bile emulsify fats into tiny droplets Duodenum
Lipid bile lipid droplets
Pancreas
▪ Secretion of pancreatic juice Synthesises of pancreas
- Pancreatic amylase hydrolyses starch into maltose
juice

- Trypsin hydrolyses polypeptides into peptides Diagram 5 Organs of liver, duodenum, and pancreas

- Lipase hydrolyses lipids droplet completely into fatty acid + glycerol

Lipid + water lipase fatty acids + glycerol

Ileum Digestion of Carbohydrates and Protein

Involved secretion of Intestinal juice from Intestinal glands

Carbohydrate Digestion Acronym for you
• Hydrolyses of Maltose (MSDS LA)

Maltose + water maltase glucose M – Mouth
• Hydrolyses of Sucrose S – Stomach
D- Duodenum
Sucrose + water sucrase glucose + fructose S- Small Intestine
• Hydrolyses of Lactose L – Large Intestine
A – Anus
Lactose + water lactase glucose + galactose
Protein Digestion
• Hydrolysis Peptides

peptides + water eripsin amino acids

Large Intestine Absorption of Remaining Water Eripsin released by the
ileum is also known as

Peptidase

Anus Egestion of faces

i-Think

Mouth Stomach Duodenum Small Large Anus
intestine intestine

Diagram 6 Flow of arrangement of organs in the alimentary canal

Absorption Absorption in Small Intestine

The Adaptations Of Ileum And Villus Epithelium Microvilli
In The Absorption Of Dissolved Nutrient cell Goblet cell

• Absorption of digested food starts in the Microvilli

duodenum and is completed in the ileum.

Transports and absorbs Capillary
nutrients from lacteal network

(a) (c)
(b)
Scan to view
internal structure of Lacteal

ileum Absorbs glycerol, fatty acids
and vitamin A, D,E, and K.

Diagram 7 (a) Part of ileum (b) Structure of villus (c)
Epithelium cell with microvillus

Absorption of Dissolved Nutrient
i-Think

Water Soluble Types of Dissolved Fat Soluble Nutrients
Nutrients Nutrient
❑ Vitamin A, D, E, and K
❑ Vitamin B and C ❑ Fatty acids and glycerol
❑ Glucose
❑ Amino acids
❑ Mineral ions

Diagram 8 Types of Dissolved nutrient

Yes! It is easy since Anna, do you think you
it already presented can explain Adaptations

in the table. of ileum and villus in
the absorption of
digested food?

Table 1 Adaptation of ileum and small intestine and its importance

Adaptation Importance

▪ The ileum is long and coiled. ✓ Prolongs the absorption time of dissolved food
▪ The villus is made up of a layer of epithelial ✓ To facilitate the absorption of nutrient to the

cells that very thin. blood or lacteal capillaries

▪ the inner wall of the ileum is greatly folded ✓ To increase the surface area of dissolved
with villi. nutrient absorption

▪ The surface of a villus epithelial cells is
covered with millions of microvilli projections

▪ Presence of goblet cells that secrete mucus ✓ To keep the surface of the villus moist

✓ Aid in lubricate the movement of undigested
food

✓ To allow nutrients to dissolve in

▪ Each villus has complete network of blood ✓ To facilitates the absorption and transport of
capillaries and lacteal. dissolved nutrients to body tissues and organs

Table 2 Method of nutrient absorption in ileum

Method of Food Digested food Absorbed through
Absorption
Vitamin A, D, E, and K Epithelial cells → Lacteal
Simple Diffusion Amino Acids Epithelial cells → blood capillaries

Facilitated Diffusion Fatty acids and glycerol Epithelial cells → Lacteal
Active Transport Vitamin B, C, and ions Epithelial cells → blood capillaries
Osmosis Fructose Epithelial cells → blood capillaries
Glucose and Galactose Epithelial cells → blood capillaries
Amnio acids Epithelial cells → blood capillaries
Water Epithelial cells → blood capillaries

Assimilation • The uptake and use of absorbed nutrients by cells for metabolism.

Assimilation of Amino acids: Deamination Assimilation of Glucose: Blood Glucose Regulation
• The liver synthesizes plasma protein • Excess glucose will be converted to glycogen

(fibrinogen & prothrombin), enzymes and and stored in the liver or the muscle by insuline
hormones • When the blood glucose level is lower than
• Excess amino acids is break down and converts
into amino group into urea to be secreted as threshold level, the liver converts the glycogen
urine or sweat back into glucose
• When the glycogen level reach its maximum,
the excess glucose is converted to fats
• Fat is stored as adipose tissue under the skin.

Diagram 9 Assimilation of digested food Assimilation of Fats & Lipid
• Lipids in the blood are used to synthesis
Detoxification
• Bacteria will be destroyed by phagocyte cells in cholesterol and plasma membrane
• Excess fats are stored as adipose tissues
the liver
• Toxic substances are transported by the blood underneath the skin and around the organs as
stored energy
to the liver and chemically converted to non - • When glucose is insufficient, fats will be
toxic substances for elimination oxidized to release energy

Do you know that LIVER is the
largest solid internal organ in

human?

It weighs approximately 3–3.5
pounds or 1.36–1.59 kilograms

Anna, what is the name of blood vessel that
carries nutrient-rich blood in our digestive

system?

That was Hepatic portal vein. It functions to
carries the blood contains absorbed nutrient
from the small and large intestine and spleen to

the liver to assimilate.

Yes. That is correct, Ana.

Defaecation • Functions of Large Intestine

Absorption of Water and Mineralls Faeces contains dead cells from the
inner layer of the intestine, waste
• Absorption of water, mineral salts, and water salts, soluble
products such as bile
vitamins (vitamin B and folic acid) pigments, bacteria and toxic
• Has no digestive activity and no presence of villi
• Chlorine and Sodium are relatively absorbed in few quantity substances.

Formation of Faeces Scan to watch
Digestion
Secretion of mucus from the walls smoothen Absorption
the movement of faeces until the anus
Defaecation

Ascending colon Appendix Descending colon
Absorption of water & Absorption of water &
vitamins vitamins

Caecum The movement of faeces
Absorption of water & ions takes about 12 to 24 hours
before entering the rectum

Elimination of stored faeces Rectum
Anus Serves as temporary storage
of the faeces

Faeces
Diagram 10 Structure of large intestine

Anal sphincter

Do you know why is Anus When the anal
faeces are brown in sphincter relaxes and
the muscle of rectum
colour? contract, faeces are
push out through anus
It is due to the
presence of bile Diagram 11 Structure of anus

pigments

2. Balance Diet Scan to learn more on Malaysia
Food Pyramid or click on
• Balanced diet contains all the 7 classes of food
(carbohydrates, lipid, protein, vitamin, mineral salts, http://www.myhealth.gov.my/e
fibers and water) with the correct proportions according n/malaysian-food-pyramid-2/

to individual’s needs
• However, a person’s need for balanced diet is influenced by many factors

i-Think Factors influences Balanced Diet

Age Sex Occupation Daily activities Health Current living
condition climate

Diagram 12 Factors influence balanced diet

Diet Modification on Specific Individuals

What are modification of diet for diabetes
mellitus and obesity patient?

Obesity patient with diabetes mellitus is advised to
avoid food that is fried and high in fats. They also

could not take food with high content of sugar.

3. Health Issues Related to Digestive System and Eating Habit

Diagram 13 Before and after gastric bypass Effects on modifying organs on human health

Gastric Bypass
• A surgery that makes a new connection of the

intestine to the stomach
• This surgery is used for obesity patient to

reduce the body weight
• It is also used to control cardiovascular

diseases, diabetes mellitus, and osteoporosis.

Can you predict the short-term and long-term
effect on patient who had gastric bypass?

Yes. I presented here in form of the table

Short-Term Effect Long-Term Effect
• Acid reflux • Dizziness
• Nausea • Low blood sugar level
• Vomiting • Malnutrition
• Expanded oesophagus • Stomach ulcer
• Certain food prohibition • Defaecation problems

Table 3 Short-term and long-term effect of gastric bypass

Health Issues related to Defaecation

Polyps

Diagram 14 Constipation Diagram 15 Colon cancer
Constipation Colon Cancer

• A condition where the stool is hard and dry is • A type of cancer that occurs on the tissues of
difficult to pass through the colon due to the colon
abnormal water absorption in the colon.
Causes of colon cancer:
• Usually, the bowel movements happens slowly, and • Prolonged constipation
absorption of water is higher • Carcinogens from the bacteria
• Toxic substances in the feaces
• Ingesting high fat and low fibre diet

Diagram 16 Diarrhea Diagram 17 Heamorrhoids
Heamorrhoids
Diarrhea
• A condition whereby the defecation is difficult • A condition whereby the veins around the anus
or lower rectum are inflamed and swollen.
to control due to watery stools in the large
intestines. Caused by:
• Chronic diarrhea that lasts for several days, • Prolonged constipation
causing the body to dehydrate. • Diarrhea
• It is usually caused by ingestion of food
contaminated by viruses, bacteria or parasites

• To prevent defaecation-related problems, we must drink a
lot of water, eats a lot of food with high fibers and
also exercise regularly.

• Fiber is not digested by our digestive system; therefore, it
helps to solidify the stool because it absorbs water and
adds bulk to stool.

Good thing, I love to drink water at least 8
glasses per day!

Health Issues Related to Eating Habits

Table 4 Health issues related to eating habits

Obesity Gastritis Anorexia nervosa Bulimia nervosa Muscle
dysmorphia
Definition ▪ Accumulation ▪ The ▪ A type of ▪ A type of
of excess fat inflammation of eating disorder eating disorder ▪ A health
in the body the lining od associated with associated with condition that
stomach psychological psychological cause individual
epithelial layer problems problems to think
constantly
▪ Originally has ▪ Originally is about building
normal body underweight or muscle on their
weight normal weight body

▪ Overweight ▪ Feel painful & ▪ Deprives ▪ Sequences of ▪ Has strict diet
▪ Slow
uncomfortable themselves excessive food and dietary
movement intake & supplement
at the upper from food ▪ Over-intensive
Symptoms ▪ Always think purging back
abdomen workouts and
▪ Nausea & that they are from stomach
▪ Common among weightlifting
vomiting fat ▪ Dissatisfaction
▪ Loss of ▪ Fear of weight young females
▪ Difficult to on appearance
appetite & gain
▪ Excessive control that leads to
weight
exercise appetite/cravin depressed

g moods or anger

Factors • Age • Irregular meal ▪ Low self- ▪ Negative ▪ Traumatic
• Unhealthy
time esteem feeling on one’s experience in
lifestyle • Excess ▪ Dissatisfied
• Genetics own body shape the past
secretion of with own’s body ▪ Mental
▪ Associate with or body weight
pepsin ▪ Low self- disturbance
• Taking too mental and
esteem
much alcohol & emotion

smoking problems

Health risks High risk to High risk to High risk to High risk to High risk to
• High blood • Gastric ulcer • Malnutrition • Malnutrition • Steroid misuse
• Stomach • Hear failure • Hear failure • Depression
pressure • Die from • Dehydration • Thought of
• Heart cancer • Mental
severe suicide
diseases disturbances • Heart failure
• Diabetes undernourishme • Stroke

mellitus nt

What are the treatments for
eating disorder such as bulimia
nervosa and anorexia nervosa??

These two health issues are treated with medication
and psychotherapy. It is best to give moral support

for them.

Summative Evaluation Do not forget to
try this Summative
1. Diagram 1 shows a line of epithelial cells at gastric gland.
Evaluation!!

Cell P

What happens if cell P is malfunction?
A. Slows the hydrolysis of protein
B. Stops the activity of salivary amylase
C. Stops the growth of bacteria in stomach
D. Less mucus produced

2. Discuss THREE (3) adaptation of villus for better absorption of nutrient in ileum.

3. Briefly explain assimilation of protein in the liver.

4. Briefly explain why diabetes patient is advised to avoid eating rice too much in their diet.

5. A man is suffering from cancer, causing his pancreas to be removed. State THREE (3)
ways that he should do to control the health problems that may arise due to the removal
of pancreas?

Scan this QR code to Or you can scan QR
check your answer! code here to do
quick revision on
Quizziz.

Try This

References

Gungor, S. N., & Ozkan, M. (2017). Evaluation of the Concepts and Subjects in Biology Perceived to
Be Difficult to Learn and Teach by the Pre-Service Teachers Registered in the Pedagogical
Formation Program. European Journal of Educational Research, 6(4), 495-508.

Khalib, J., Sudin, S., Abd Wahid, R., & Ibrahim, N. H. (2021). Chapter 9: Nutrition and Human
Digestive System. In Focus Biology SPM Tingkatan 4&5 KSSM (First edition 2021, pp. 124–145).
Pelangi Sdn. Bhd. 2021.

Salleh, W. N. W. M., Ahmad, C. N. C., & Setyaningsih, E. (2021). Difficult topics in Biology from the
view point of students and teachers based on KBSM implementation. EDUCATUM Journal of
Science, Mathematics and Technology, 8(1), 49-56.

Tan, M. H. (2021). Chapter 9: Nutrition and Human Digestive System. In Module & MORE Biologi
Tingkatan 4 KSSM (First edition 2021 , pp. 117–129). Pelangi Sdn. Bhd. 2021.

Yat, G. W., Abd Aziz, N. A., Mohd. Yusuf, Y., & Ibrahim, N. H. (2019). Chapter 9: Nutrition and
Human Digestive System. In Biology Form 4 KSSM (Textbook) (First edition 2021 , pp. 142–161).
(S. Melkion & M. H. Kahar, Eds.; M. Haris, N. A. Abd Aziz, & Y. Mohd. Yusuf, Trans.). Ministry of
Education Malaysia. 2019.

Posted October 12, 2017 in C. M. (2021, July 15). 4 types of learners in education: Advancement
courses. Advancement Courses' Teacher Resources. Retrieved February 1, 2022, from
https://blog.advancementcourses.com/articles/4-types-of-learners-in-education/

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Diagram 3 system/
Diagram 4
Diagram 5 [Digestive system]. Servier Medical Art: SMART.
Diagram 7 https://smart.servier.com/category/anatomy-and-the-human-body/digestive-
Diagram 9 system/

Diagram 10 [Digestive system]. Servier Medical Art: SMART.
Diagram 11 https://smart.servier.com/category/anatomy-and-the-human-body/digestive-
Diagram 13 system/
Diagram 14
Diagram 15 [Digestive system]. Servier Medical Art: SMART.
Diagram 16 https://smart.servier.com/category/anatomy-and-the-human-body/digestive-
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[Digestive system]. Servier Medical Art: SMART.
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[Digestive system]. Servier Medical Art: SMART.
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Yat, G. W., Abd Aziz, N. A., Mohd. Yusuf, Y., & Ibrahim, N. H. (2019). Chapter 9. 9.4
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[Digestive system]. Servier Medical Art: SMART.
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[Gastric bypass]. Mymeditravel. https://www.mymeditravel.com/gastric-bypass-
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[Constipation]. The Nemours Foundation.
https://kidshealth.org/Nemours/en/parents/az-symptoms-constipation.html

[Digestive system]. Servier Medical Art: SMART.
https://smart.servier.com/category/anatomy-and-the-human-body/digestive-
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[Diarrhea]. Freepik. https://www.freepik.com/free-vector/cartoon-character-with-
diarrhea-symptoms_9819163.htm

[Digestive system]. Servier Medical Art: SMART.
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