ms. stacey-ann joseph hsb section b: life...

Ms. Stacey-Ann Joseph HSB

1 | P a g e

Section B: Life Processes

Describe the major nutrients and their sources.

Nutrients:

The food we eat contains different kinds of nutrients.

Food are consumed to:

Provide energy for our cells to carry out all the functions of life

Provide the raw materials for the new biological material needed in our bodies

for growth, and also to repair and replace damaged and worn out cells.

Provide the resources needed to fight disease and maintain a healthy body.

Macro-nutrients provide the bulk of our food and are the proteins,

carbohydrates and fats.

Micro-nutrients are vitamins and minerals because only small quantities are

required.

The nutrients are:

Carbohydrates

Proteins

Fats/ Lipids

Mineral salts

Vitamins

Water

Dietary Fibre/ Roughage is also necessary

Carbohydrates:

- Contains the three elements C, H, O.

- Carbohydrates are obtained from plant foods.

- They include sugars and starches.

Starch molecules are made up of thousands of glucose (sugar) molecules

linked together in a long chain. Starch is insoluble in water. Foods

containing starch are bread, potatoes and cereals.

Sugars: Glucose like all sugars is soluble and tastes sweet. Glucose is a

simple sugar meaning that its molecule is made up of one sugar unit. The

sugar obtained from sugar cane is called sucrose, this is a complex sugar


2 | P a g e

made up of two simple sugar molecules; glucose and fructose linked

together.

Reducing Sugars:

Monosaccharides: are the simplest carbohydrates. They have the formula

C6H12O6.

They include: glucose and fructose.

Non-Reducing Sugars:

The more complex sugars are groups of simple sugar molecules built up

into long chains. The simplest consists of two units of monosaccharides

joined together (disaccharides).

Disaccharides include: lactose from milk, sucrose from cane sugar and

maltose.

Polysaccharides are the most complex carbohydrate and are long chain

molecules made up of smaller repeating units.

Glucose/ Fructose: Monosaccharides

Sucrose: Disaccharide

O

Glycosidic

Bond


3 | P a g e

Disaccharide Source Monosaccharide units

Sucrose Stored in plants such as sugar

beet and sugar cane

Glucose + Fructose

Lactose Milk sugar- this is the main

carbohydrate found in milk

Glucose + Galactose

Maltose Malt sugar- found in

germinating seeds such as

barley

Glucose + Glucose

Proteins:

- Contains the elements C, H, O, N and sometimes S (Sulphur)

- A protein molecule is made up of many smaller molecules all linked together in a

long chain. These smaller units are called amino acids.

- There about 20 different amino acids. They can be linked together in any order.

Any change in the order makes a different kind of protein.

- Eggs contain a protein called albumin.

- There are different proteins in the body each performing a different function.

Protein Function

Haemoglobin Transporting oxygen

Enzymes Catalyzing metabolic reactions

Keratin Making skin, nails and hair strong and waterproof

Antibodies Destroying invading bacteria and viruses

Collagen Making bone and cartilage tough

- Soluble proteins are haemoglobin and enzymes and insoluble proteins are keratin

and collagen.


4 | P a g e

Lipids:

- Contains the elements C, H, O.

- The atoms of these elements are arranged together very differently, so lipids have

very different properties than carbohydrates.

- Lipids include fats and oils. Fats are lipids that tend to be fairly solid at room

temperature and mostly comes from animals. Oils tend to be liquid at room

temperature and mostly comes from plants.

Lipids are insoluble in water.

- Lipids is used as an energy source. They contain twice as much as carbohydrates.

- Plant oils usually contain unsaturated fats. These help protect from heart disease.

Fish oils are also unsaturated fats.

- Animal fats and oils are mostly saturated fats. This increases the risk of

developing arteriosclerosis and heart diseases.

Mineral salts:

- The human body needs many different minerals which are inorganic ions.

Vitamins:

- A vitamin is a nutrient that is needed in small quantities in the diet. If we do not

have enough of a particular vitamin, then we may suffer from a deficiency

disease.


5 | P a g e

Summary of Macro-nutrients:

Nutrient Chemical parts Test to detect Rich food

source

Function in

body

Protein C, H, O, N Biuret Meat, fish, egg,

plant legumes

not such a

variety of amino

acids

Growth and

repair, part of

enzymes,

structural parts

of molecules e.g.

haemoglobin

and insulin

Carbohydrates:

Sugars

Starches

Cellulose

C, H, O form

glucose,

2x more

hydrogen than

oxygen

Benedict’s test

for reducing

sugars, iodine

solution for

starch

Sugar, bread and

cakes

Vegetables,

cereal and bran

Provide energy,

stored as

glycogen in

animals and

provides

roughage for

peristalsis

Fat C, H, O form

glycerol and

fatty acids,

Fewer oxygen

molecules

Grease spot,

emulsion

Butter, lard, pork

and oils

Provide energy,

insulation,

solvent for

vitamins A and

D, forms cell

membranes


6 | P a g e

State the functions and the main source of vitamin A, B1, C, D and the minerals calcium and

iron

Mineral Salts:

Element Daily

requirement

Use in the

body

Deficiency

results in

Some good

sources

Calcium 0.7-2.0g Formation of

bones and teeth,

assists in blood

clotting, muscle

contraction

Osteoporosis Milk, cheese,

green

vegetables

Iron 5-15mg Forms

haemoglobin in

red blood cells

Anemia Green

vegetables,

liver, yeast, egg

yolk, kidney

Iodine 0.1mg Forms

thyroxine in the

thyroid gland

Goitre and

reduced growth

(dwarfism)

Sea fish,

iodized table

salt, cheese

Phosphorus 1.0g Formation of

bones and teeth,

needed in the

nucleus and as

ATP for energy

release

Rickets Cheese, meat,

fish, eggs and

nuts


7 | P a g e

Vitamins:

Vitamin Rich source Deficiency results in Functions

A

Retinol

Fish liver oil, egg

yolk, butter, cheese,

abundant in carrots,

green vegetables

and palm oil.

Night blindness,

damage to

membranes

Can be made from

carotene, Keeps vision

healthy.

B1

Thiamine

B2

Riboflavin

Yeast, egg yolk,

liver, kidney, whole

grain of wheat and

rice

Beri-Beri Proper functioning of

nerve cells

C

Ascorbic

acid

Citrus fruits and

green vegetables

Scurvy, wounds heal

slowly

Needed to make collagen,

aids in the formation of

liver bile

D

Calciferol

Animal fats, butter,

fish liver oils, egg

yolk

Rickets- calcium not

absorbed,

Osteomalcia-

decalcification of

bones resulting in

softness.

Can be made from

ergosterol and sunlight, in

the skin.

Needed for healthy bones

and teeth, immunity and

blood cell formation

E

Tocopherol

Vegetable oils,

nuts, green leafy

vegetables

Weakness of red

blood cells, nervous

system development

problems (child)

Antioxidant that protects

cell membranes and other

fat soluble parts of the

body, such as LDL

cholesterol (bad) from

damage

K

Menaquinone

Kale, spinach,

Brussels sprout,

soybean oil, canola

oil, olive oil

Hemophilia,

hemorrhages

(newborn), bleeding

Helps transport calcium,

for proper bone growth and

blood coagulation

(clotting)


8 | P a g e

State the cause, symptoms and treatment of deficiency diseases.

Deficiency Cause Symptoms Treatment

Night Blindness Vitamin A

deficiency

- Difficulty seeing in

the dark

- Poor vision in

discontinuous lighting

Vitamin A supplements.

A diet that includes a large

source of Vitamin A:

- Fish, Liver, Carrots,

Green leafy vegetables

Anemia Iron deficiency - Fatigue and loss of

energy

- Shortness of breath

and headaches

- Dizziness

- Pale skin

Iron Supplements.


source of Iron:

- Red meat

- Dark, green and leafy

vegetables

- Iron fortified cereals

Rickets Vitamin D

deficiency

- Pain or tenderness in

the bones of the arms,

legs, pelvis, or spine.

- Stunted growth and

short stature.

- Bone fractures.

- Muscle cramps.

- Teeth deformities,

such as: delayed tooth

formation, holes in the

enamel

- Skeletal deformities,

including; an oddly

shaped skull, bowlegs,

or legs that bow out.

Vitamin D supplements


source of Vitamin D:

- Fish, Liver, Milk or Eggs


9 | P a g e

Classify vitamins as fat or water soluble

Fat soluble vitamins:

- Soluble in fats solvents (non-polar solvents)

- Relatively insoluble in water

- These are stored in the body for long periods of time

- Examples include; vitamins A, D, E and K

Water soluble vitamins:

- Vitamins that are not stored in the body and easily excreted

- Must be consumed regularly as foods or supplements to maintain a healthy lifestyle

- Soluble in water

- Examples include; vitamins B1 and C

Equations involved in Nutrition:

Difference between glucose and fructose:

The formation of sucrose:

Condensation

Hydrolysis


10 | P a g e

Proteins:

Lipids:

- Triglyceride

- Stearic Acid: Saturated fatty acid- carbon atoms joined by a single covalent bond

- Linoleic Acid: Unsaturated fatty acid- carbon atoms have one or more double bonds.

Condensation

Amino acid 1 Amino acid 2

Dipeptide Water

Hydrolysis


11 | P a g e

Perform tests to distinguish among food nutrients

Starch: Iodine solution

- Method:

Solid sample:

1. Peel off the skin of any vegetables e.g. potato and fruits as these are often impermeable.

Use a clean spatula to remove samples of powdered food. Avoid cross contamination

with other foods.

2. Add a few (2-3) drops of bench iodine solution to a piece of solid food on a white tile.

3. Make observations.

Liquid sample:

1. Add 10 cm3 of the liquid food sample to a clean, dry test tube.

2. Add about 5 drops of iodine solution to the test tube.

3. Note any colour changes.

4. To prepare a control, perform steps 1 -3 for distilled water.

- A blue black colour indicates the presence of starch


12 | P a g e

Reducing sugars: Benedict’s Reagent

- These sugars react readily with Benedict’s solution. They reduce copper (II) ions to

copper (I) ions and are therefore reducing sugars. The reducing sugars include all of

the monosaccharides and some of the disaccharides.

- Method:

1. Bring the water to boil in the beaker using the Bunsen burner.

2. In one boiling tube add water to a depth of about 2cm. This will act as your

control.

3. In another tube add a sample of glucose powder and water to a depth of about

2cm.

4. Place any food samples to be tested in other boiling tubes in the same way.

5. Add a few drops of Benedict’s solution to each boiling tube- enough to colour the

mixture blue.

6. Place the tubes in the boiling water and leave for several minutes. Take care with

the boiling water.

7. If a reducing sugar is present the clear blue solution will change as an orange red

precipitate appears.

Non-reducing sugars:

- Method:

1. Bring the water to boil in the beaker using the Bunsen burner.

2. In one boiling tube add water to a depth of about 2cm. This will act as your

control.

3. In another tube add a sample of sucrose and water to a depth of about 2cm.


13 | P a g e

4. Place any food samples to be tested in other boiling tubes in the same way.

5. Add a few drops of hydrochloric acid to each tube. Place them in the beaker of

boiling water and boil the mixture for about 2 minutes.

6. Allow the tubes to cool a little, and then add a few drops of sodium hydrogen

carbonate solution to neutralize the acid in each tube. (When the solution no

longer fizzes when you add the sodium hydrogen carbonate, the contents are

neutral).

7. Now add Benedict’s reagent to each tube and carry out the test for reducing

sugars as normal.

8. If a non-reducing sugar such as sucrose is present, it will have been hydrolyzed

into its monosaccharide units by the acid and so these reducing sugars will now

react with the Benedict’s reagent and change color.

Protein: Biuret Reagent (5% KOH or NaOH and 1% CuSO4 solution)

- Method

1. In one boiling tube add water to a depth of about 2cm. This will act as your control.

2. In another tube add a sample of protein powder (albumin) and water to a depth of

about 2cm. Shake to mix.

3. Place any other food samples to be tested in other test tubes in the same way.

4. Add an equal volume of dilute potassium or sodium hydroxide solution and mix.

5. Add a few drops of dilute copper sulphate solution. (N.B: if biuret reagent is

available skip steps 4 and 5 replacing it with a few drops of biuret reagent).

6. A purple (mauve) colour will develop if protein is present.


14 | P a g e

Lipids: Emulsion Test

- Method

1. Place a sample of ethanol in a dry test tube to a depth of about 2cm.

2. Place a small sample of food in a dry test tube and add a similar amount of ethanol.

3. Shake the food to dissolve any lipid in the ethanol.

4. Take two more test tubes and about half fill each with water.

5. Carefully pour the contents of the tube containing food into one of the tubes

containing water.

6. Pour the pure ethanol into the other tube containing water and compare the two. If

lipid is present a white, cloudy layer forms o top of the layer of water.


15 | P a g e

State the functions of water in the body

Water:

Function of water Examples

To form part of all body fluids In blood, lymph, tissue fluid etc.

For numerous chemical reactions By hydrolysis to break down food molecules

As a solvent It dissolves nutrients during digestion

For transport around the body Blood transports many substances such as urea etc.

Within cells for support Much cell support comes from turgor pressure

To produce cooling By evaporation of sweat

For cleaning and personal hygiene By washing the body, laundry, clothing, dishes

Cooking food By boiling to soften food and destroy pathogens

State the role of dietary fibre in the body

Dietary Fibre:

- Some food cannot be digested

- Most of this indigested material is fibre

- Fibre is mostly cellulose from plants. This is a carbohydrate but we do not have the

enzyme to digest it.

- Fibre is important to the diet as it stimulates the muscles of the alimentary canal (gut)

to work.

- Fibre helps to keep food moving through the alimentary canal

- Without fibre everything slows down and a person may become constipated.


16 | P a g e

Describe the causes and effects of constipation and diarrhea

Constipation:

- Constipation is caused due to an insufficient amount of dietary fibre/ roughage being

consumed.

- Roughage is important in the large intestines, where with the absorption of water, the

faeces are kept soft for movement and for passing out of the body.

Diarrhoea:

Food poisoning causes diarrhoea. It usually causes gastroenteritis which makes

the person generally feel unwell. For example; it may be caused by bacteria

called Salmonella which causes sickness and diarrhoea.

Avoid contamination by keeping food safe from bacteria and fungi as well as

practicing proper hygiene during preparation of food. The harmful ones are most

likely deposited on the food by:

- People’s hands that have not been washed after using the toilet and have come in

contact with faeces.

- Someone sneezing or blowing their nose over food.

- Houseflies, cockroaches, rats or other pests that may have been feeding on rubbish or

other contaminated material.

- Contact with other food that already has microorganisms growing on it.

Avoid bacterial growth by placing food in the refrigerator or freezer. It does not

kill the microorganisms slows microbial growth.


17 | P a g e

Explain what is meant by a balanced diet

A balanced diet:

- A balanced diet contains the correct amount of nutrients, in the right proportions for

all our needs, including maintaining good health.

- Diet must include:

Carbohydrate and fat sufficient to provide energy for all activities. Some fat is

also important for cell membranes.

Proteins for growth and repair.

Foods that prevent deficiency diseases: Vitamins and Minerals

Water and roughage (dietary fibre is necessary for peristalsis and emptying of

large intestines).

- Growing children requires more protein for growth and repair whereas a manual

labourer will require more carbohydrates for energy.

- The energy present in food is given in kilojoules.

- A balanced diet is different for different people and will vary according to age,

gender, physical activity and religion.

- Caribbean diet includes yam, rice, plantain, cassava, potato, corn, pasta, oatmeal,

breadfruit, fish coconuts and most fruits including bananas. In the Caribbean, the

most frequent nutrient deficiencies may include vitamin A and iron but others may be

present based on our respective diet.


18 | P a g e

Explain the effects of malnutrition on the human body

A balanced diet includes a sufficient amount of all the major food groups (carbohydrates,

proteins, lipids, minerals, vitamins, water and fibre) to supply the energy and nutrients

needed to maintain the cells, tissues and organs of your body in a healthy state and to

support healthy growth and development of your body when it is needed.

If too little food is eaten this results in under-nutrition and if too much food is eaten it

results in over-nutrition, or any one element of the diet is lacking then you will suffer

from malnutrition.

Malnutrition suggests that:

The diet has too many kilojoules in it, so the person becomes seriously

overweight.

The diet has too few kilojoules in it, so the person becomes seriously

underweight.

The diet does not contain enough of one or more nutrients, for example a

vitamin, which could lead to the development of a deficiency disease.

The diet contains too many saturated fats, which increases the risk of heart

disease.

The table below gives the daily energy requirements per day for respective individuals.

Age/ Sex/ Occupation Energy needed/ day (kJ)

Newborn baby 2000

Child aged 2 5000

Child aged 6 7500

Girl aged 12-14 9000

Boy aged 12-14 11000

Girl aged 15-17 9000

Boy aged 15-17 12000

Female office worker 9500

Male office worker 10500

Heavy manual worker 15000

Pregnant woman 10000

Breastfeeding woman 11300

Woman aged 75+ 7610

Man aged 75+ 8770


19 | P a g e

Illnesses associated with malnutrition:

Obesity:

Being seriously overweight

Increases the risk of several diseases including heart diseases and diabetes.

In order to reduce weight, fewer kilojoules must be consumed

Anorexia:

A mental illness in which a person has a distorted image of their body, and

thinks that they are too fat when in reality they are too thin.

The person eats very little and loses so much weight that they become

seriously ill.

If untreated results in death

Bulimia/ Binge eating:

A psychological and severe life-threatening eating disorder where an

abnormally large amount of food is consumed in a short period of time,

followed by an attempt to avoid gaining weight by purging what was

consumed.

Methods of purging include; forced vomiting, excessive use of laxatives or

diuretics and extreme or prolonged periods of exercising.

Kwashiorkor:

This is a form of malnutrition when there is not enough protein in the diet.

Children who develop this disorder may not grow or develop properly and

may remain stunted for the rest of their lives.

Kwashiorkor causes a buildup of fluid in the body that can cause the face to

become round and the belly to become distended.

Marasmus:

Marasmus is a form of severe malnutrition. It can occur in anyone who has

severe malnutrition, but it usually occurs in children.

The main symptom of marasmus is being underweight. Children with this

condition have lost a lot of muscle mass and subcutaneous fat. Subcutaneous

fat is the layer of fat just under the skin. Dry skin and brittle hair are also

symptoms of marasmus.


20 | P a g e

Seriously malnourished children may look older and have little to no energy

or enthusiasm for anything. It is as a result of a carbohydrate deficiency

Determine body mass index

Body mass index (BMI)

The Body Mass Index (BMI) is a guide to whether someone is underweight,

normal weight or overweight. You can calculate the BMI using this formula:

BMI = mass in kg ÷ (height in m) ²

The meaning of BMI’s are shown below in the table:

BMI Meaning

Under 18.5 Underweight

Between 18.5 and 24.9 Normal

Between 25 and 29.9 Overweight

Between 30 and 39.9 Obese

Over 40 Very obese

Relate the types of teeth present in an infant and an adult human to their roles

Teeth:

When a baby is born, it has no teeth.

At the age of approx. 24-30 months a child has a set of 20 teeth.

Most of these are classified as deciduous or milk teeth.

They are gradually replaced by permanent teeth at an age of about 7 years.

The eight molars at the back do not fall out. These eight (8) plus the replaced

ones (12) together with twelve (12) new ones, make up a complete set of

permanent teeth.

Most people have all their permanent teeth (32 altogether) at an age of about 17

years.


21 | P a g e

Labeled diagram below showing milk teeth of a child:

N.B. Baby teeth, also called deciduous teeth, do not have premolars. Instead, in the

places where adults have premolars, children have what dentists call first molars. Once

this fall out, they are replaced by premolars as theory states BUT THE TEXTBOOK

STATES THAT CHILDREN HAVE PREMOLARS SO PLEASE FOLLOW THE

TEXT. THIS ALSO AFFECTS THE DENTAL FORMULA WHICH I HAVE

EDITED TO SUIT.

Labeled diagram below showing permanent teeth of an adult:

Premolar

Premolar

Premolar

Premolar


22 | P a g e

Roles of teeth:

Incisors: chisel- shaped teeth at front to cut off pieces of food. There are 8 in total

in the upper and lower jaw.

Canine: pointed in shape and tears tough food. There are 4 in total in the upper

and lower jaw.

Molars and Pre-molars: have larger flat surfaces with ridges for grinding food.

There are a total of 8 pre-molars and 12 molars in total in the upper and lower

jaw.

Dental formula:

- The kind and number of teeth are explained in the form of formula called the dental

formula.

Dental formula of a child: Dental formula of an adult:

Child 20 deciduous/milk teeth Adult 32 permanent teeth

Incisors: 2/2 Incisors: 2/2

Canine: 1/1 Canine: 1/1

Premolars: 2/2 Premolars: 2/2

Molars: 0/0 Molars: 3/3

Describe the importance of teeth in the process of digestion

Importance of teeth in the role of digestion: Mastication

Mastication, or chewing, is the first step of digestion and serves to increase the

surface area of the material brought into the oral cavity so that enzymes in saliva

can begin to break down the food more efficiently.


23 | P a g e

Describe the structure and function of the typical tooth

Vertical-section of a tooth:

Relate the structures of the tooth to their functions

Structure Function

Crown Surface for biting and crushing food

Neck In gum for support

Root In bone socket, holds tooth

Enamel Covers crown, very hard surface prevents wear

Dentine Bulk of tooth, similar to bone

Pulp cavity Nerves and blood vessels, supplies nutrients and sensitivity

Cement Lines root, holds tooth in place

Periodontal membrane Provides support with flexibility

Root opening Small passage for nerves and blood capillaries


24 | P a g e

State the causes of tooth decay

Causes of tooth decay:

Not brushing and flossing your teeth regularly and not seeing a dentist for

checkups and cleanings.

Eating foods that are high in sugar and other carbohydrates, which feed the

bacteria in your mouth.

Not getting enough fluoride. Fluoride helps prevent tooth decay by making teeth

more resistant to acids produced by plaque. Fluoride is added to many public

water supplies.

Not having enough saliva. Saliva washes away food and harmful sugars, so it

helps protect your teeth from decay. A dry mouth may be caused by a condition

such as xerostomia or Sjögren's syndrome, by taking certain medicines, or by

breathing through your mouth. Older adults are more likely to have a dry mouth.

Having diabetes.

Smoking, using spit (smokeless) tobacco, or breathing secondhand smoke.

Describe the process of tooth decay

Process of tooth decay:

Germs (bacteria) in our mouth grow on the teeth every day and help in the formation

of plaques.

Plaque is the sticky deposits that collect, in particular, around the gum line, the edges

of fillings and the grooved surfaces of the teeth.

If plaque is allowed to collect over time it will harden into a substance called tartar.

The plaque uses the food and drink that we eat (especially sugars) to make acid. Some

foods, like fizzy drinks and lollies are already acidic.

This acid attacks the tooth's outer layers (enamel and dentine) and eats them away

(erosion).

Over time, a small hole known as a cavity can develop on the surface of the tooth

(enamel).


25 | P a g e

The bacteria can also infect the tissue within the pulp, causing a dental abscess. Tooth

decay typically occurs in the teeth at the back of your mouth, known as the molars

and premolars. These are large flat teeth that you use to chew food. Due to their size

and shape and rough surface, it is easy for small particles of food to get stuck on and

in between these teeth. They are also harder to clean properly.

Once cavities have formed in the enamel, the plaque and bacteria can reach the

dentine. As the dentine is softer than the enamel, the process of tooth decay speeds

up. Erosion is faster.

Without treatment, the plaque and bacteria will then enter the pulp. At this stage, your

nerves will be exposed to the bacteria, making your tooth very painful.

The bacteria can also infect the tissue within the pulp, causing a dental abscess.

Tooth decay typically occurs in the teeth at the back of your mouth, known as the

molars and premolars. These are large flat teeth that you use to chew food. Due to

their size and shape and rough surface, it is easy for small particles of food to get

stuck on and in between these teeth. They are also harder to clean properly.

Effects of tooth decay:

The tooth could break

The nerve or pulp could get infected

The nerve could die

You could get toothache

You could get swelling of your face

You might feel sick

You might need a filling

You might need to have the tooth taken out. If it was a front tooth it would spoil

your lovely smile.


26 | P a g e

Outline the guidelines for the care of the teeth

Guidelines for the care of teeth:

Regular dental visits (treat damaged teeth)

Proper brushing with toothpaste after meals and at night (remove decaying food)

Eat hard, crisp foods (stimulates membrane blood supply)

Eat foods with calcium, phosphorus and vitamins; C and D (for growth)

Fluoride in water (prevents decay)

Do not suck fingers (distorts growth in young babies)

Reduce sugar in diet (makes acids which destroys enamel)

Use dental floss (to remove plaque)

Use disclosing tablets (to show bacteria present)

ms. stacey-ann joseph hsb section b: life...

Documents