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Unit 1: Chapter 3- Food and Nutrition - Coggle Diagram
Unit 1: Chapter 3- Food and Nutrition
Functions of food
Growth and repair of body cells
To build the chemicals required for metabolism (
enzymes and hormones
)
To produce energy in respiration
To aid continuity of life
Protei
n
Elements:
Carbon, Hydrogen, Oxygen and
N
itrogen
(Sometimes Sulphur and Phosphorus)
Fibrous
proteins - Little or no folding (e.g. proteins found in
hair, skin and nails
)
Globular
proteins - Lots of folding (e.g.
protein hormones, enzymes and antibodies
)
Examples
Hormones:
chemical messengers e.g.
insulin
Enzymes:
involved in digestion e.g.
amaylase breaks down starch into maltose.
Muscles:
e.g.
myosin
pigments:
e.g.
haemoglobin and chlorophyll
Structural Function
Found in cell membranes of cells along with phospholipids
Keratin:
hair and nails
Myosin and Actin
: Muscles
Collagen:
Bones, Ligaments and tendons
Metabolic Function
Enzymes:
In digestion
Hormones:
e.g. insulin which
controls
blood sugar levels
Pigments:
haemoglobin and chlorophyll
Dietary sources of protein:
Meat, fish, eggs, nuts, nuts, peas, beans and milk.
Amino acids:
Smallest form of proteins
Peptide
= less than 20 amino acids.
Polypeptide
= +20 amino acids
Protein
= +200 amino acids
Basic Structure:
amino acid + Peptide bonds = Peptide chain
Important Note:
The body
cannot
store excess protein - it is broken down in the liver into
Urea
by a process called
Deamination.
Urea then travels to the kidneys where it is excreted.
Urine = urea + salts + water
Fats / Lipids
Elements:
Carbon Hydrogen Oxygen (
CHO
).
Structural Function
Phospholipids are a part of cell membrane
Fat cells (
adipose tissue
) insulate the body
Protect delicate internal organs
Secretes sebum (
oil
) - protects skin.
Metabolic Function
Make energy in respiration (
long-term energy source
)
Basic structure:
1 Glycerol + 3 fatty acids (
triglyceride
)
Oils:
Liquid at room temperature
Fats:
Solid at room temperature
Phospholipids
: one fatty acid is replaced with a phosphate
Dietary sources:
Meat, eggs, cheese, butter, oils, margarine
Nutrients / Biomolecules:
Are organic chemicals produced and found only within living organisms
Common
elements
found in food: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous, Sulphur (
C,H,O,N,P,S
).
5 elements present in the body as
dissolved salts:
Sodium, Magnesium, Chlorine, Potassium, Calcium (
Na, Mg, Cl, K, Ca
).
Carbohydrates
Elements:
Carbon, Hydrogen, Oxygen - Ratio of H:O = 2:1 (Glucose = C6H12O6)
General Formula:
Cx(h2o)y
Basic Structure:
Disaccharide
2 Saccharides
Examples
Malt
ose
(barley)
Sucr
ose
(table sugar)
Lact
ose
(Milk)
Functions
Metabolic function:
Disaccharides are metabolised to make
energy in respiration
.
Polysaccharide
+2 Saccharides
Examples
Storage Polysaccharide
Plants
store glucose as
strach
in chloroplasts
Humans
store glucose as
glycogen
in liver and muscle cells
Structural polysaccharide
Cellulose
(fibre): Cell wall of plants
Chitin
: Cell walls of fungi
Functions
Structural function:
Cellulose give strength and support to plants. Cellulose stimulates
peristalsis
- aids digestion, prevents constipation.
Monosaccharide
1 Saccharide
Examples
Gluc
ose
(Fruit)
Fruct
ose
(Fruit)
Galact
ose
(Milk)
(also called
reducing sugars
)
Functions
Metabolic function:
Glucose is used to make
energy
in respiration.
Vitamins
Vitamins are organic molecules needed by organisms in very small amounts because they cannot be made in the body -
must be obtained from food
Fat-soluble:
A,D,E,K
Vitamin D
Dietary sources:
Dairy foods - milk, cheese, yoghurts
Non-Dietary sources:
Sunshine
Function:
Healthy bones and teeth
Deficiency disease:
Rickets, Osteoporosis, Osteomalacia and tooth decay
Water-solube:
B,C
Vitamin C
Dietary sources:
Oranges, lime and lemon
Functions:
Helps the
absorption of iron
in the body. (
Lack
of iron is called
anemia
Makes connective tissue
to support skin and blood vessels
Deficiency Disease:
Scurvy (bleeding gums, loose teeth and wounds are slow to heal)
Minerals
These are called
trace elements
because they are needed in small amounts.
Calcium
Function - Animals
Strong bones and teeth
Sources:
Dairy - milk, cheese and yoghurt
Function - Plants
Holds plant cells together
Sources:
Salts absorbed through soil
Iron
Function - Animals
Forms
haemoglobin
in red bood cells
Sources
: Liver Spianch
Lack of Iron:
Anaemia
Magnesium
Function - Animals
Formation of bones
Sources:
fish
Function - Plants
Formation of
chlorophyll
lack of which lead to reduced rate of photosynthesis
Sources:
Salts absorbed through soil
Water
It makes up
70-95% of cell mass
It is an excellent
solvent
in which
all biochemical reactions occur
It
participates in chemical reactions
- e.g.
photosynthesis, respiration and digestion
.
Carries substances around
the
body of animals and plants
Good
absorber of heat energy
Responsible for the
turgidity of plant cells