Transcript Proteins - Animal Nutrition

Nutrition in Animals
Learning Objectives for
Nutrition in Animals
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Basic Biological Molecules
Chemical Digestion
The Human Alimentary Canal
Absorption & Assimilation
Lesson Objectives
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Different Biological Molecules
Major Food Groups
Food Tests
Biological Molecules
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Food Groups
Food Tests
Biological Molecules
Major Food Groups
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Carbohydrates
Proteins
Fats
Food Test Demonstration
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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
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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
Learning Objectives for
Nutrition in Animals
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Basic Biological Molecules
Chemical Digestion
The Human Alimentary Canal
Absorption & Assimilation
Lesson Objectives
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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
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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
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Revisiting the Carbohydrates
Hydrolysis
Carbohydrases breaks
downReaction
carbohydrates into simple
sugars (monosaccharide)
Polysaccharides=>Disaccharides =>Monosaccharides
Chemical Digestion
Carbohydrates – Condensation Rxn
Monosaccharides=>Disaccharides =>Polysaccharides
Condensation
Condensation
Functions of Carbohydrates
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Glucose is required for cellular respiration to
provide energy.
Glycogen serves as an energy store.
Revisiting the Proteins
Hydrolysis Reaction
Proteases breaks down proteins into amino acids
Protein
=>
Polypeptide => Amino acids
Chemical Digestion
Proteins – Condensation Rxn
Proteases breaks down proteins into amino acids
Amino Acid => Polypeptide => Protein
Condensation
Weak bonding
Functions of Proteins
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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
Hydrolysis Reaction
Lipases breaks down fats into glycerol and fatty acids
Lipid
=> Glycerol
&
Fatty Acids
Chemical Digestion
Functions of Fats/Lipid
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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
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Hydrolysis reactions
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Condensation reactions
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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.
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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.
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Summary for Nutrients
Carbohydrates
Monosaccharide
Disaccharide
Polysaccharide
(simple sugar)
(double sugar)
(complex sugar)
e.g. glucose,
galactose,
fructose
e.g. maltose,
lactose,
sucrose
e.g. starch,
glycogen,
cellulose
Summary for Nutrients
Proteins
Amino Acids
Polypeptide
Proteins
Chains
e.g. adenine,
methionine
e.g. enzymes,
antibodies
Summary for Nutrients
Fats
Fatty Acids
Glycerol
Fats/Lipids
e.g. adipose tissues,
phospholipids
Learning Objectives for
Nutrition in Animals
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Basic Biological Molecules
Chemical Digestion
The Human Alimentary Canal
Absorption & Assimilation
Lesson Objectives
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Parts of the Human Alimentary Canal
Functions of the Human Alimentary Canal
Peristalsis
The Human Alimentary Canal
Nutrition in Human
Human Alimentary Canal
Processes and Functions
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Ingestion – the process of taking in food into
the alimentary canal through the mouth.
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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 Canal
Processes and Functions
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Absorption – the process where digested
food substances are taken up by the body
through the blood stream.
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Assimilation – the process where the
nutrients absorbed are converted into new
protoplasm and/or used to release energy for
the body
Human Alimentary Canal
Processes and Functions
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Egestion – the process where indigestible
and unabsorbed material are removed from
the alimentary canal through the anus.
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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
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Salivary glands
Salivary amylase
Starch →
Maltose
Oesophagus
Food is broken down into
smaller bits by chewing
(physical digestion).
increases surface area of food
substances.
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Salivary glands produce
salivary amylase that breaks
down starch into maltose.
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The bolus is swallowed and
being pushed along the
oesophagus by peristalsis.
Peristalsis
Peristalsis
Longitudinal muscles
Epidermal layer
Lumen
Circular muscles
Antagonistic muscles
Stomach
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Gastric juices is secreted into
the stomach.
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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)
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Pepsin
Protein → Poly-peptides
Small intestine and peripheral organs
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Liver
Gall
bladder
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Bile duct
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Pancreas
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Duodenum
Lipase
Fats → Fatty acid + Glycerol
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.
Small intestine and peripheral organs
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Liver
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Gall
bladder
Bile duct
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Pancreas
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Duodenum
Trypsin
Protein → Poly-peptides
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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.
Small intestine and peripheral organs
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Liver
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Gall
bladder
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Bile duct
Pancreas
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Duodenum
Erepsin
Poly-peptides → Amino acids
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.
Large intestine, rectum and anus.
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colon
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appendix
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rectum
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.
Digestion (pancreatic enzymes)
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Starch
Protein
Fat
amylase
trypsin
lipase
maltose
polypeptides
fatty acids and glycerol
Digestion (intestinal enzymes)
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Maltose
Polypeptides
Fats
maltase
erepsin
lipase
glucose
amino acids
fatty acids and glycerol
Learning Objectives for
Nutrition in Animals
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Basic Biological Molecules
Chemical Digestion
The Human Alimentary Canal
Absorption & Assimilation
Lesson Objectives
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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
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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
Increased surface area
can help increase the rate
of absorption of nutrients.
The intestinal walls are
lined with networks of
blood capillaries.
folds
Adaptations in the Alimentary Canal
Diagram of a villus showing
the blood capillary network
and the lacteal.
microvilli
folds
Blood
capillaries
Lacteal
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
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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
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Insulin will promote
the conversion of glucose
into glycogen in the liver
Glucagon will promote
the conversion of glycogen
into glucose in the liver
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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.
Metabolism of Amino Acids
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The liver will deaminate excess
amino acids to form urea.
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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.
Breakdown of Alcohol
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The liver will detoxify
alcohol to form other
harmless products.
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.
Summary of Digestion
Carbohydrates
(polysaccharides)
Proteins
(polypeptides)
Fats/Lipids
(polymer)
Glucose
(monosaccharides)
Amino Acids
DIGESTION
(monomers)
Fatty Acids/Glycerol
(monomers)
e.g. Glycogen
(polysaccharides)
e.g. Enzymes
ASSIMILATION
(polypeptides)
e.g. Adipose Tissue
(polymers)
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
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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:
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1. Which are the food product/s that should be tested for the
presence of the mutant bacterial strain?
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2. Which are the food product/s likely to be utilized by the mutant
bacterial strain for its metabolism?
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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:
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4. Examine the results for the food test for presence of mutant
bacterial strain so as to determine the cause of acute food
poisoning.
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5. Suggest who might be responsible for poisoning Annabel,
indicating the contaminated food item, and support your deduction
with logical reasoning.