nutrition in animals. learning objectives for nutrition in animals basic biological molecules...

Nutrition in Animals

Learning Objectives for Nutrition in Animals Basic Biological Molecules Chemical Digestion The Human Alimentary Canal Absorption & Assimilation

Lesson Objectives

Different Biological Molecules Major Food Groups Food Tests

Biological Molecules

Food Groups Food Tests Biological Molecules

Major Food Groups

Carbohydrates Proteins Fats

Food Test Demonstration

Starch (Iodine Test) Reducing Sugar (Benedict’s Solution

Test) Protein (Biuret Test) Fat (Ethanol Emulsion Test)

Food Tests

Starch (Iodine Test) Add Iodine to

sample.

Food Tests

Reducing Sugar (Benedict’s Solution Test)

Add Benedict’s Solution to sample. Boil mixture for no more than 2

minutes.

Food Tests

Protein (Biuret Test) Add Sodium Hydroxide (NaOH) to

sample. Add Copper II Sulphate (CuSO4) drop

by drop.

Food Tests

Fat (Ethanol Emulsion Test) Add Ethanol to sample and shake. Add Water to mixture and shake.

Biological Molecules

Water Carbohydrates Proteins Fats

Water

No one owes Singapore a living

Discuss with your partner and write on:

- the importance of water in our lives

- methods to conserve water at home/school

Basic Biological Molecules Chemical Digestion The Human Alimentary Canal Absorption & Assimilation

Learning Objectives for Nutrition in Animals

Lesson Objectives

Chemical Digestion Structure and Functions of Biological

Molecules

Reflection time…

DO NOT WASTE FOOD

Food for thought.

Carbohydrates

Carbohydrases breaks down carbohydrates into simple sugars (monosaccharide)

Polysaccharides=>Disaccharides =>Monosaccharides

Chemical Digestion

Carbohydrates

Examples of monosaccharide- glucose, fructose, galactose Examples of disaccharide- maltose, sucrose, lactose Examples of polysaccharide- starch (amylose, amylopectin), glycogen

Proteins

Proteases breaks down proteins into amino acids

Protein => Polypeptide => Amino acids

Chemical Digestion

Fats/Lipids

Lipases breaks down fats into glycerol and fatty acids

Lipid => Glycerol & Fatty Acids

Chemical Digestion

Revisiting the Carbohydrates

Examples of monosaccharide- glucose, fructose, galactose Examples of disaccharide- maltose, sucrose, lactose Examples of polysaccharide- starch (amylose, amylopectin), glycogen

Revisiting the Carbohydrates

Carbohydrases breaks down carbohydrates into simple sugars (monosaccharide)

Polysaccharides=>Disaccharides =>Monosaccharides

Chemical Digestion

Hydrolysis Reaction

Carbohydrates – Condensation RxnMonosaccharides=>Disaccharides

=>Polysaccharides

Condensation Condensation

Functions of Carbohydrates

Glucose is required for cellular respiration to provide energy.

Glycogen serves as an energy store.

Revisiting the Proteins

Proteases breaks down proteins into amino acids

Protein => Polypeptide => Amino acids

Chemical Digestion

Hydrolysis Reaction

Proteins – Condensation Rxn

Proteases breaks down proteins into amino acids

Amino Acid => Polypeptide => Protein

Condensation Weak bonding

Functions of Proteins

Amino acids are converted into protein to make protoplasm.

Enzymes are made of proteins. Antibodies are made of proteins. Excess amino acids are not stored and

will be removed via deamination in the liver.

Revisiting the Fats/Lipids

Lipases breaks down fats into glycerol and fatty acids

Lipid => Glycerol & Fatty Acids

Chemical Digestion

Hydrolysis Reaction

Functions of Fats/Lipid

Fat is required for the cell membrane. Adipose tissue helps to insulate the

body and keep the body warm. Adipose tissue also helps protect the

vital organs. Fats are energy store and can be

utilised for respiration to provide energy.

Summary for Nutrients

Hydrolysis reactions- A chemical reaction where a

large and complex molecule into 2 smaller and simple molecules.

- A molecule of water is used up in the process.

Condensation reactions- A chemical reaction where 2

simple molecules are joined together to form a larger and more complex molecule.

- A molecule of water is produced in the process.

Summary for Nutrients

e.g. glucose, galactose,

fructose

Carbohydrates

Polysaccharide

(complex sugar)

Disaccharide

(double sugar)

Monosaccharide

(simple sugar)

e.g. maltose, lactose, sucrose

e.g. starch, glycogen, cellulose

Summary for Nutrients

e.g. adenine,methionine

Proteins

ProteinsPolypeptide

Chains

Amino Acids

e.g. enzymes,antibodies

Summary for NutrientsFats

Fats/Lipids

Glycerol

Fatty Acids

e.g. adipose tissues,phospholipids

Basic Biological Molecules Chemical Digestion The Human Alimentary Canal Absorption & Assimilation

Learning Objectives for Nutrition in Animals

Lesson Objectives

Parts of the Human Alimentary Canal Functions of the Human Alimentary

Canal Peristalsis

The Human Alimentary Canal

Nutrition in Human

Human Alimentary CanalProcesses and Functions Ingestion – the process of taking in food into

the alimentary canal through the mouth.

Digestion - the process of the breaking down of large, complex and insoluble substances into small, simple and soluble molecules by the action of enzymes; so as to facilitate the absorption of nutrients into the body.

Human Alimentary CanalProcesses and Functions Absorption – the process where digested

food substances are taken up by the body through the blood stream.

Assimilation – the process where the nutrients absorbed are converted into new protoplasm and/or used to release energy for the body

Human Alimentary CanalProcesses and Functions Egestion – the process where indigestible

and unabsorbed material are removed from the alimentary canal through the anus.

Egestion = Excretion*

*Excretion is the removal of metabolic waste products from the body through the excretory system (to be covered in later topics)

Buccal Cavity Food is broken down into

smaller bits by chewing (physical digestion).

- increases surface area of food substances.

Salivary glands produce salivary amylase that breaks down starch into maltose.

The bolus is swallowed and being pushed along the oesophagus by peristalsis.

Salivary glands

OesophagusSalivary amylase

Starch → Maltose

Peristalsis

Peristalsis

Longitudinal muscles

Epidermal layer

Lumen

Circular muscles

Antagonistic muscles

Stomach Gastric juices is secreted into the stomach.

Gastric juices contain hydrochloric acid, pepsin and rennin.

- hydrochloric acid kills bacteria.- hydrochloric acid lowers the pH

in the stomach (pH 2~3).- pepsin breaks down protein to

polypeptides.- rennin curdles the milk.- salivary amylase action stops

due to the low pH. (non-optimal pH conditions)

Pepsin Protein → Poly-peptides

Small intestine and peripheral organs Liver makes bile

Bile is stored in gall bladder and secreted into the duodenum via the bile duct.

- bile increases the pH (pH 9~10)- bile emulsifies fat. - emulsification of fat increases

the surface area for fat digestion.

- lipases will break down the fats into fatty acid and glycerol.

Liver

Gall bladder

Pancreas

Bile duct

Duodenum

Lipase Fats → Fatty acid + Glycerol

Small intestine and peripheral organs Pancreas produces pancreatic

juices. Pancreatic juices are secreted

into the duodenum via the pancreatic duct.

- pancreatic juices increases the pH (pH 9~10).

- pancreatic juices contains pancreatic amylase, pancreatic lipase, and trypsin.

- trypsin breaks down protein to polypeptides.

- gastric juices actions stop.

Liver

Gall bladder

Pancreas

Bile duct

Duodenum

Trypsin Protein → Poly-peptides

Small intestine and peripheral organs Small intestine produces

intestinal juices. Small intestine absorbs most of

the nutrients at the end of ileum.

- intestinal juices contains erepsin, lipases and carbohydrases.

- erepsin breaks down polypeptides into amino acids.

Liver

Gall bladder

Pancreas

Bile duct

Duodenum

ErepsinPoly-peptides → Amino acids

Large intestine, rectum and anus.

Colon absorbs the remaining water content and mineral salts.

Rectum serves as a temporary storage for indigestible material and unabsorbed material.

The anus is the opening where faeces is egested out of the body.

colon

rectum

anus

appendix

Starch maltose Protein polypeptides Fat fatty acids and glycerol

amylase

trypsin

lipase

Digestion (pancreatic enzymes)

Maltose glucose Polypeptides amino acids Fats fatty acids and glycerol

maltase

erepsin

lipase

Digestion (intestinal enzymes)

Basic Biological Molecules Chemical Digestion The Human Alimentary Canal Absorption & Assimilation

Learning Objectives for Nutrition in Animals

Lesson Objectives

Absorption of nutrients Roles of the liver

Absorption of nutrients

Nutrients absorbed in the Digestive System would be carried to parts of the body via the Circulatory System (Blood).

Adaptations in the Alimentary Canal The Human Alimentary Canal (from the mouth to the

anus) is approximately 6.5 metres long. Why?

-Food takes time to be digested.

-The longer food stays in the body, more nutrients can be absorbed.

Adaptations in the Alimentary Canal

folds

Increased surface area can help increase the rate of absorption of nutrients.

The intestinal walls are lined with networks of blood capillaries.

Adaptations in the Alimentary Canal

folds

Diagram of a villus showing the blood capillary network and the lacteal.

Blood capillaries

Lacteal

microvilli

The hepatic portal vein

Nutrients absorbed from the small intestine is transported to the liver via the hepatic portal vein

Nutrients absorbed from the large intestine is transported to the liver via the hepatic portal vein

Roles of the Liver

Metabolism of Glucose Metabolism of Amino Acid (Formation of

Urea) Metabolism of Fats Breakdown of Red Blood Cells Breakdown of Alcohol Production of heat.

Metabolism of Glucose Insulin and Glucagon are secreted

by the pancreas to regulate the blood glucose levels in the body.

In a healthy individual, insulin is secreted when blood-glucose level is high.

- Insulin promotes the uptake of glucose into the liver and the conversion of glucose into glycogen.

In a healthy individual, glucagon is secreted when blood-glucose level is low.

- Glucagon promotes the conversion of glycogen into glucose and the release of glucose into the bloodstream.

Insulin will promote the conversion of glucose into glycogen in the liver

Glucagon will promote the conversion of glycogen

into glucose in the liver

Metabolism of Amino Acids Excess amino acids will be found in

the human body after the person has taken in large amount of protein.

The excess amino acids will be deaminated to form urea.

Urea is toxic and is removed from the body via the kidney.

Urea is a metabolic waste product.The liver will deaminate excess

amino acids to form urea.

Breakdown of Alcohol Alcohol is broken down in the liver

into harmless substances through detoxification.

When there is surplus of nutrients in the body, alcohol is converted into fats and stored in the body.

When there is a shortage of nutrients in the body, alcohol is broken down by enzymes to release energy.

The liver will detoxify alcohol to form otherharmless products.

Summary of Digestion

Carbohydrates(polysaccharides)

Glucose(monosaccharides)

e.g. Glycogen(polysaccharides)

Proteins(polypeptides)

Amino Acids(monomers)

e.g. Enzymes(polypeptides)

Fats/Lipids(polymer)

Fatty Acids/Glycerol(monomers)

e.g. Adipose Tissue(polymers)

DIGESTION

ASSIMILATION

File Case 00129042009

Annabel: found dead at home in her room by her mother at 3pm.

Suspect 1: Joanne (Annabel’s mother)

Recently divorced, Status complicated

Has depression and suicidal tendency

Suspect 2: Nicholas (Annabel’s brother)

Studies at SARS University:

Life-Sciences undergrad, specializing in toxins

On bad terms with Annabel, Sibling rivalry.

Suspect 3: Bruce (Joanne’s boyfriend)

Bought all the food ate by Annabel before she died.

Annabel finds him unworthy of her mother.

Coroner’s Report

Cause of death: Acute food poisoning due to presence of neurotoxin produced by

mutant bacterial strain; Mutant bacterial strain is similar to Pseudoalteromonas tetraodonis,

a well-known marine bacterium that produces a neurotoxin that is very potent, usually found in puffer fish and other venomous marine animals.

Other evidences gathered

Unpublished blog posting from Annabel. Recorded statements from suspects. Preliminary food test results. Food test results for the presence of mutant bacterial strains.

(currently in progress)

Directives:

1. Which are the food product/s that should be tested for the presence of the mutant bacterial strain?

2. Which are the food product/s likely to be utilized by the mutant bacterial strain for its metabolism?

3. Suggest a possible reason for the observation in the Iodine test performed on the food samples collected from the body of the deceased.

3. Suggest a possible reason for the observation in the Iodine test performed on the food samples collected from the body of the deceased.

Directives:

4. Examine the results for the food test for presence of mutant bacterial strain so as to determine the cause of acute food poisoning.

5. Suggest who might be responsible for poisoning Annabel, indicating the contaminated food item, and support your deduction with logical reasoning.