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BIOLOGICAL COMPOUNDS &

NUTRIENTS

Organic molecules

• Molecules are called organic compounds if they:

• contain carbon-to-carbon bonds AND• are made exclusively by plants and/or

animals,• (This naturally excludes compounds like

CO2, which is made by living organisms, but not exclusively— plenty-of other processes produce CO2). 2

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INORGANIC COMPOUNDS

ORGANIC COMPOUNDS

1. Do not contain the element CARBON (except as single carbon atoms - CO2 )

1. Always contain the element carbon (forming chains)

2. They are usually raw materials from the environment

2. Made by Living organisms

4. Do not burn 4. Burn (Combustible)

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ORGANIC COMPOUNDS

• Contains CARBON with either a HYDROGEN or another/other CARBON/S attached to it.

• CO2:• CH4

• CCl4:• C6H12O6:

ORGANIC

INORGANIC

ORGANIC

ORGANIC

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CARBOHYDRATES• "CARBO" = CARBON;

"HYDRATE" = WATER • Hence the elements

are Carbon, Hydrogen and Oxygen and the

• ratio of Hydrogen to oxygen is ALWAYS 2:1 (2 hydrogen's for every 1 oxygen, as in water)

C6H12O6 = glucose C12H22O11 = sucrose

Formula = CnH2nOn

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Monosaccharides – the monomers of carbohydrates

• Monosaccharides (single sugar units) E.g., Glucose, fructose, galactose• Properties Soluble in water, sweet, can form crystals• Functions Serve as a source of energy e.g. glucose.

• Disaccharides are made from monosaccharides as follows• GLUCOSE + FRUCTOSE sucrase (enzyme) + H2O

(found in )

• GLUCOSE + GLUCOSE maltase (enzyme) + H2O (found in )

• GLUCOSE + GALACTOSE lactase (enzyme) H2O (found in )

• In each case, enzymes remove one ______________ molecule by a process called __________________ to join the two smaller molecules together.

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SUCROSE

GERMINATING SEEDSMALTOSE

DAIRY - MILKLACTOSE

SUGAR – FOR TEA

WATERCONDENSATION

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• Physical properties: Soluble in water and sweet to the taste.

• When 2 monosaccharides react together they form a disaccharide (meaning two sugar units). This reaction is known as condensation and this reaction involves the removal of a water molecule.

Disaccharides

CONDENSATION- H2O

glycosidic bond

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POLYSACCAHRIDES • A polysaccharide is a POLYMER ("poly" = many), made

of many single units or monosaccharides called MONOMERS

• Polysaccharides are formed by condensation reactions where many monosaccharides are joined together, in a process generally called POLYMERISATION. Polysaccharides are hydrolysed (by the addition of water) into simple monosaccharides .

• They are insoluble in water and are not sweet.

Examples of polysaccharides are

• CELLULOSE - • LIGNIN -• GLYCOGEN -• STARCH –• PECTIN -

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CELL WALLS – PRIMARY

CELL WALLS –SECONDARY (WATERPROOF)

IN LIVER AND MUSCLES

IN LEUCOPLASTS

IN MIDDLE LAMELLA

• Made by CONDENSATION of many glucose units only

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Physical properties of Carbohydrates

• Simple carbohydrates are soluble in water

• Polysaccharides are generally insoluble in water

• Monosaccharides and most disaccharides taste sweet

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FOR ALL ORGANISMS1. They are a good source of __________________ ____________________

energy, such as glucose.2. They form part of nucleic acids DNA and RNA.

FOR PLANTS FOR ANIMALS3. Plants store food as

_______________ in seeds and bulbs.

3. Animals store food as ____________in muscles and liver.

4. Plants transport food as glucose in a tissue called __________________.

4. Animals transport food as glucose in the ____________ ______________.

5. Carbohydrates like _____________ & ____________ form part of cell walls.

5. Carbohydrates like _____________ form part of the exoskeleton of insects.

6. __________________ in plants keeps cells glued together

7. __________________ forms an important source of roughage in our diets.

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CHEMICAL POTENTIAL ENERGY

STARCH GLYCOGEN

PHLOEMBLOOD

STREAM

CELLULOSE LIGNIN CHITIN

PECTIN CELLULOSE

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LIPIDS OR FATS• C, H & O• Ratio of

H:O = >2:1• 1 Glycerol

and 3 fatty acids

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THE DIFFERENT FATTY ACIDS MAKE UP THE DIFFERENT LIPIDS

• SHORTER FATTY ACIDS FORM OILS

• LONGER FATTY ACIDS FORM SOLIDS (BUTTER)

• VERY LONG FATTY ACIDS FORM WAXES

1 = GLYCEROL

2 = FATTY ACID3 = ESTER BOND

• Fatty acids are classified as being SATURATED OR UNSATURATED

• Saturated Fatty Acids have _______________________ carbon –to-carbon bonds so they are completely saturated with hydrogen. These tend to occur in ____________________ fats like butter and cream, and they generally increase cholesterol in the body. Limit them in your food!

• Unsaturated fatty acids have ________________ C-to-C bonds, so some spaces are not saturated with hydrogen. They occur mainly in _______________ oils like canola oil and olive oil, etc., and they decrease cholesterol. It’s much healthier to consume these fats than animal fats.

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SINGLE

ANIMAL

DOUBLE

PLANT

• Your body needs cholesterol to make new cells, insulate nerves and produce some hormones. Normally the _________makes all the cholesterol you need, but people also take in cholesterol with foods like _________, _______________ and ________________________.

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Cholesterol and heart disease:

RED MEATEGGS MILK

LIVER

Cholesterol and heart disease:• High cholesterol can

cause a cardiovascular problem called ATHEROSCLEROSIS - fat is deposited between the epithelial and muscle layer of blood vessels, causing the lumen / cavity to become _________________ so a partial blockage develops & slows down blood flow.

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NARROWER

• In the heart, this causes a reduced supply of oxygen to the heart muscle, causing _________ called

• _______________. A __________ __________ will result if the obstruction causes a complete blockage.

• Cholesterol is transported in the blood in 2 forms;• LDL's (Low Density Lipoproteins): also called

_______________ cholesterol. This contains little protein and much cholesterol and Is the chief agent causing arterial blockage (e.g., ________________, _______________)

• HDL's (High Density Lipoproteins): Also called ____________ cholesterol. This form has lots of proteins and little cholesterol. If actually works to ___________ fatty deposits in the blood stream.

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PAINANGINA HEART ATTACK

BAD

BUTTERCREAM

GOODREDUCE

• REMEMBER: High cholesterol levels in the blood stream cause NO SYMPTOMS at all

• Everyone over the age of 20 should have their cholesterol levels checked at least every 5 years, thereby decreasing their chances of heart disease. It's definitely also advisable to decrease _____________________ fats and INCREASE PLANT FATS, fruit and vegetables in the diet.

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ANIMAL

• Fats or lipids are formed when I glycerol and 3 fatty acids are joined by enzymes by means of _______________________________.

• 1 glycerol + 3 fatty acids 1 lipid + 3 H20• The process ___________________can be used to

break the lipid down again:• 1 lipid + 3 H20 molecules 1 glycerol + 3 fatty acids

• 2.4 Physical properties of lipids:

• They are insoluble in _______________________.• They are soluble in

______________________________________ etc.• They are hydrophobic, i.e.,

_________________________. 21

CONDENSATION

HYDROLYSIS

WATER

REPEL WATER

ALCOHOL, ETHER, AMMONIA

Biological importance of Lipids:

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FOR ALL ORGANISMS1. They are the best form of _______________________________ energy

in the form of stored fats). Gram for gram, they have more than TWICE the energy in carbohydrates).

2. They form part of all _______________________ in plants and animals.

3. Lipids are important for waterproofing leaves and insects by means of a waxy layer called the _______________________________.

FOR ANIMALS1. Lipids __________ delicate organs like kidneys and eyes from

injury.2. Lipids under our skin ______________________________ the body

against heat loss in cold weather.3. Lipids are important for the absorption of fat-soluble

________________ like Vit. A and D.

CHEMICAL POTENTIAL

CELL MEMBRANE

CUTICLE

PROTECT

INSULATE

VITAMINS

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PROTEINS• C, H, O,

NITROGEN (+ P,S)

• No fixed H:O ratio, varies greatly.

• Consist of the monomers amino acids joined together.

There are 20 natural amino acids, used to construct MANY, MANY proteins.

Monomers of Proteins

• The ___________________ __________ form the basic molecules (monomers) of which proteins are constructed.

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AMINO ACIDS

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DIPEPTIDE

TRIPEPTIDE

POLYPEPTIDE

A molecule is only called a protein if it contains more than _________ amino acids.. TheSmallest known protein is ____________, which has 51 amino acids; others have thousands.

50INSULIN

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Dipeptides• There are 20 naturally occurring amino acids

which we call the essential amino acids for life. • The amino acid MONOMERS are used to build up

proteins. • Amino acids join to each other by a

CONDENSATION REACTION. WATER is removed in a reaction between the amino group of one amino acid and the carboxyl group of the other.

• They are broken down by means of HYDROLYSIS• The bond between the amino acid molecules in a

protein molecule is called a PEPTIDE BOND

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HYDROLYSIS• Notice in the drawing below, we have

shown the HYDROLYSIS, where water is added to break up sucrose into two monosaccharides, one glucose and one fructose molecule.

+

Sucrase enzyme

HYDROLYSIS+ H2O

Amino acids are joined together by _____________ and broken down by ____________________

CONDENSATION

HYDROLYSIS

PHYSICAL PROPERTIES - PROTEINS

• They are ____________________ (large)• Sensitive to changes in _____

(acidity/alkalinity)• Sensitive to ______________ (cold does

not affect the structure but high temperatures can cause a breakdown in their structure called _________________

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MACRO-MOLECULES

pH

TEMPERATURE

DENATURATION

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The Denaturing of Proteins:Normal protein (with its _______________________ bonds intact and able to function.

Denatured Protein:bonds are __________ so it loses its ___________ and can’t function.

INTRA-MOLECULAR

BROKENSHAPE

CAUSES:• pH • Temperature increase

Biological importance of Proteins:FOR ALL ORGANISMS

1. Proteins form part of ______________________, the living substance in cells.

2. They form part of all _____________ __________, e.g., nuclear membrane.3. They act as ___________, speeding up biochemical reactions.4. They form a structural part of _________________________, together with

DNA.5. They can be used as a _______________________ when carbohydrates and

lipids are in short supply. This is for emergencies only.FOR ANIMALS

1. Some hormones like _________ are proteins (it controls blood glucose level)

2. Proteins can be ___________ like melanin or haemoglobin.3. Some proteins act as part of the immune system, e.g.,

____________________ in blood.30

PROTOPLASM

CELL MEMBRANES

ENZYMES

CHROMOSOMES

ENERGY SOURCE

INSULIN

PIGMENTS

ANTI-BODIES

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Polymers• All organic compounds are built up into

POLYMERS by the process of _______________________ and can be broken down by _________________, e.g., during digestion.

• METABOLISM consists of building up processes called _____________________________ and breaking down processes called ________________________________.

CONDENSATIONHYDROLYSIS

ANABOLISM

CATABOLISM

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FOOD TESTS• All the tests described below are CONTROL

TESTS to show what a positive result looks like - we will be using the actual substance we are lasting for with the appropriate method.

• This will show you what a positive test looks like, so that further tests on food samples can be COMPARED with these controls.

• When you are testing a food sample, DO NOT ADD THE SUBSTANCE TESTED FOR! 33

• Two procedures to be followed when testing food samples for various compounds:

• ___________________________________

• ___________________________________

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CRUSH IT OR CUT IT FINELY TO INCREASE THE SURFACE AREA OF THE REAGENT TO REACT WITH

ADD WATER TO CREATE A LIQUID MEDIUM FOR THE CHEMICAL RECTIONS TO WORK IN

GLUCOSE TEST• Place a small amount of glucose powder (or food) into a test tube. Addwater

& shake it. Light a Bunsen burner.• Add a few drops of BENEDICTS SOLUTION to the mixture and shake.• Use a test tube holder to heat the solution over the flame, moving it

constantly and keeping the open end of the test tube away from people. (Heat Is used here to ____________________________________________________

• Record colour changes. DO NOT overheat the mixture - stop when it boils,• RESULT:• No glucose • some glucose • more glucose • lots of glucose• CONCLUSION

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SPEED UP THE RATE OF THE REACTION

BLUEGREEN

YELLOWREDDISH-ORANGE

IF A SUBSTANCE TURNS ORANGE IN THE PRESENCE OF BENEDICT’S SOLUTION AND HEAT, IT CONTAINS GLUCOSE

TO TEST FOR THE PRESENCE OF STARCH:• Place a small amount of starch powder (or food) Into a test tube and

add a little water. Shake it. No heat is needed - why? ____________________________

• Add a few drops of IODINE SOLUTION and shake it.• Record colour changes.•  RESULT: • ______________________________________________________

• CONCLUSION:

• ______________________________________________________

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THE REACTION IS FAST ENOUGH

BROWN IODINE CHANGES TO BLUE-BLACK

ANY FOOD THAT TURNS FROM BROWN TO BLUE-BLACK IN THE PRESENCE OF IODINE CONTAINS STARCH.

Biological Compounds Page 9• All organic compounds are built up into

POLYMERS by the process of _______________________ and can be broken down by _________________, e.g., during digestion.

• METABOLISM consists of building up processes called _____________________________ and breaking down processes called ________________________________.

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CONDENSATIONHYDROLYSIS

ANABOLISM

CATABOLISM

TO TEST FOR THE PRESENCE OF PROTEINS: • The Biuret test:• Put a small amount of raw egg white (or food) into a test tube. Add a little• water and shake It gently.• Add a few drops of COPPER SULPHATE solution (CuS04).• Use a different dropper to fill about one third of the test tube SODIUM

HYDROXIDE solution (NaOH).• Go back to your group and shake the test tube when you get there, note

colour changes.• RESULT:

• ____________________________________________________________

• CONCLUSION:

• ____________________________________________________________38

COLOUR CHANGES: BLUE TO VIOLET

ANY FOOD THAT TURNS VIOLET WITH CuSO4 (COPPER SULPHATE) AND NaOH (CAUSTIC SODA) CONTAINS PROTEIN

Page 11FOOD TEST

REAGENT

HEAT? Positive test:

Colour?

Negative test: Colour?

GlucoseStarchProtein

sBiuret test

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BENEDICTS

IODINE

CuSO4

+NaOH

YES

NO

NO

GR/YE/OR

BLUE-BLACK

MAUVE/PURPLE

BLUE

BROWN

NONE

Food labels• To compare different foods, use the

Nutritional content per 100g (this is also easily converted into % (30g per 100g = 30%

• Keep fat content to a minimum• Water is seldom included (if it adds up to

less than 100g, the remainder is water).• Carbohydrates include only digestible

(starch, sugar), not fibre, cellulose• Go for fewer refined carbs (like sugars) 40

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WORKSHEET RELATING TO FOOD LABELSExamine the label of a Aero chocolate bar

Nutritional information Per 100g Per 45g

servingEnergy 2196 kJ 989 kJ

Carbohydrates 57,6 g 26 gFats 29,9 g 13,4 g

Proteins 6,5 g 3,0 g

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1.Which compound forms the majority of this food item? __________________ (1)

2.What is the main specific carbohydrate in an Aero bar likely to be?

• ______________________________________ (2)

3 Use the serving size to calculate the percentage fats in this food item. Show your working.

(3)4 Do you think that these fats are likely to be

saturated or unsaturated? Give a reason for your answer.

(2)43

CARBOHYDRATES

LACTOSE. AERO IS A CHOCOLATE AND IS MADE OF DAIRY AND ADDED SUGAR (SUCROSE)

29,9/100 X 100 = 0,299 X 100 = 29,9% (OR 29,9G OF 100G = 29,9%)

SATURATED: CHOCOLATE CONTAINS CREAM WHICH CONTAINS SATURATED FATS

• If a person needs 150 g of protein in a day to maintain her body, how many of these bars should she consume daily if she eats nothing else? Give your answer to the nearest whole bar.

_____________________________________________ (3)• Would you suggest that she eats Aero bars in order to

obtain the correct protein content in her diet? Give a reason for your answer.

• ____________________________________________(3)• Calculate the percentage water in this food item• __________________________________________ (2)

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150G/3G = 50 = 50 BARS.

NO WAY! ALTHOUGHS HE GETS THE REQUIRED PROTEINS SHE WILL EAT TOO MUCH FAT AND CARBOHYDRATES.

100 – (57,6 + 29,9 + 6,5) = 6/100 = 6%

VitaminsVitamins: Group of complex organic compounds, needed in small quantities that help your body maintain normal metabolism, growth, and development.

Vitamins mainly made by plants and animals obtain theirs from the food they eat.

• They have no energy value - taking a vitamin supplement can't "give you energy", but can optimise certain functions like energy release from food.

• They act as important REGULATORS in body processes and are essential in the maintenance of good health.

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Two Groups of Vitamins:• Water-Soluble

• Fat-SolubleWater-Soluble Vitamins: • Vitamins that dissolve in water

and are NOT stored in your body for future use

Vitamin B and Vitamin C

Vitamins

Fat-Soluble Vitamins: • Vitamins that dissolve into

and are transported by fat

• They can be stored in fat tissue, the liver, and the kidneys.

• Vitamins A, D, E, and K

Vitamins

Examples of Fat-Soluble Vitamins:• Vitamin A: • Essential for forming of a pigment in

the rods of the eye (retina) to see in dim light. Maintains good vision, promotes body cell growth, helps protect teeth–Food sources: green vegetables (carrots, spinach, gem squash), dairy products

–Deficiency diseases: Nightblindness

Vitamin B3: Acts as a co-enzyme in cell respiration, assisting energy release from food.–Food sources: Red meat, unrefined cereals, Marmite, Bovril

–Deficiency disease: Pellagra – skin rashes, redness, swollen red tongue, diarrhea

Examples of Water-Soluble Vitamins:

• Vitamin C: Essential for formation of collagen and plays a role in immunity (fights against infection, maintains healthy gums, strengthens and maintains blood vessel structure)–Food sources: citrus

fruits, tomatoes, strawberry, pineapple, guava, leafy vegetables

Deficiency disease: Scurvy & anaemiaBleeding gums, poor wound healing, frequent infections

• Vitamin D: Essential for absorption of calcium and phosphorus and thus hardening bones and teethFood sources: eggs, cod liver oil, salmon,

butter, margarine, fortified breakfast cereal. Other sources include sunlight

Deficiency disease: Rickets (children) - soft bones causing bow-legs or knock knees

• Vitamins found in all the major food groups but, NO ONE FOOD CONTAINS ALL THE REQUIRED VITAMINS.

• A balanced diet is the best way to ensure that one gets all the necessary vitamins.

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IMPORTANCE OF WATER IN NUTRITION1. RAW MATERIAL FOR _______________________

(and a waste product of cellular respiration)2. CHEMICAL REACTIONS IN CELLS ALWAYS TAKE

PLACE IN THE MEDIUM OF WATER. Water acts as a ______________________. Ions, atoms and molecules are SOLUTES which dissolve in water before being able to react.

3. WATER CAN BE INVOLVED IN A CHEMICAL REACTION CALLED _______________ ("hydro" = water; "lysis" = to dissolve or break down Water actually is involved in the reaction (usually digestion) and it splits a larger molecule into smaller molecules.e.g. Maltose + water = glucose + glucose maltase (enzyme)

PHOTOSYNTHESIS

SOLVENT

HYDROLYSIS

4. WATER IS _________________________ MEDIUM FOR SUBSTANCES, e.g. foods, gases and waste products in the blood circulation of animals or in the phloem of plants.

5. WATER EVAPORATES FROM THE SKIN AND THEREFORE COOLS THE BODY (IT HELPS THE BODY TO REGULATE ITS TEMPERATURE)

6. WATER ACTS AS A _______________________, REDUCING FRICTION, e.g. in the joints of the body, allowing freer movement.

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A TRANSPORT

LUBRICANT

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MINERALS• 20, inorganic, NOT MADE BY PLANTS

OR ANIMALS• Macro-elements are elements required in

LARGE QUANTITIES BY AN ORGANISM.

• Micro-elements are elements required in SMALL QUANTITIES BY AN ORGANISM (they are also known as TRACE ELEMENTS).

MACRO-NUTRIENTS

Main purpose SOURCE DEFICIENCY

Nitrogen*

Essential for formation of ________________ which make up ___________________

Essential for ___________________ formation

Milk Cheese ___________

Stunted growth

___________ in plants

(yellow leaves)

Magnesium

All three are needed for _________________________________________________________

Milk Eggs ____________ All three leads

to _______________ in children soft bones. They work with Vitamin _____

Phosphorus Milk Eggs ____________

Calcium

Milk Eggs ____________ ____________

____________

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PROTEINS

AMINO ACIDS

CELL MEMBRANEMEAT

CHLOROSIS

HARDENING OF BONES AND TEETH

MEAT

CHEESE

CHEESEGREEN VEGETABLES

RICKETS

D

MICRO-NUTRIENTS

Iron*

Part of ___________________ in red blood cells

Liver ___________ ___________ ____________

____________

____________ Too few red blood cells,

lack of energy.

Iodine

Part of the hormone ___________________that regulates metabolic rate

______________ Swollen thyroid gland, tiredness.

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HAEMOGLOBIN MEATEGGSRAISINSGREEN VEGG

ANAEMIA

THYROXINSEA FOODIODISED TABLE SALT VEGETABLES

GOITRE