Food Flashcards
Food is needed for:
-energy
-growth of new cells
-repair of existing cells, tissues, organs etc.
Food supplies materials & energy for:
-metabolism
-continuity’ of life
Food is made up of (chemical elements):
- C (carbon)
- H (hydrogen)
- O (oxygen)
- N (nitrogen)
- P (phosphorus)
- S (sulfur)
Food is made up of (salts):
- Na (sodium)
- Mg (magnesium)
- Cl (chlorine)
- K (potassium)
- Ca (calcium)
Food is made up of (trace elements):
- Cu (copper)
- Fe (iron)
- Zn (zinc)
*CIZ
How food is formed:
Elements combine in different ratios to form bio-molecular molecules
Biomolecule
molecule found in living thing
Food biomolecules
- carbohydrates
- vitamins
- water
- lipids
- minerals
- proteins
What is human body made up of:
water - 65%
protein - 18%
fat - 10%
carbohydrate - 5%
vitamins - 1%
minerals- 1%
Elements - carbohydrates
- C (carbon)
- H (hydrogen)
- O (oxygen)
Formula - carbohydrates
Cx(H2O)y
Ratio - carbohydrates
2:1
(hydrogen : oxygen)
(carbohydrate) monosaccharides
- single sugar molecules
- simple sugars
- soluble in water
- sweet to taste
- smallest carbohydrate unit
(carbohydrate) Name examples of monosaccharides & where it’s found
(e.g. glucose & fructose)
(fruit)
(carbohydrate) disaccharides
- 2 monosaccharide sugar units joined together
- soluble in water
- sweet to taste
(carbohydrate) Name example of disaccharides & where it’s found
(e.g. sucrose, lactose, maltose)
(sugar, milk)
(carbohydrate) polysaccharides
-many monosaccharide sugar units
- insoluble in water
- are not sweet tasting
(carbohydrate) Name example of polysaccharides & where it’s found
(e.g. starch, cellulose, chitin)
(found in bread, pasta, rice)
Structural polysaccharides
- cellulose (plant cell walls)
- chitin (insect exoskeleton and fungi)
name storage polysaccharides
starch (plants)
glycogen (animals)
lipids include (eg):
-fats (solid @ room temp)
-oil ( liquid @ room temp)
- steroids (ie cholesterol &some sex hormones)
-waxes (covering insect bodies & plant leaves)
(lipids) elements:
carbon, hydrogen, oxygen
(lipids) types of molecules:
fatty acids
glycerol
(lipids) types
triglycerides
phospholipids
Triglyceride
smallest lipid
Phospholipid
One fatty acid of lipid molecule replaced by phosphate group
Sources of lipid
Fat
butter
cooking oils
fresh cream
Protein elements:
Carbon hydrogen oxygen nitrogen
(proteins) sources
lean meat
fish
eggs
soya
Structure of proteins
-Long chains of amino acids
-joined by peptide bonds
-forms polypeptide chains
Peptide contains:
Less than 20 amino acids
Polypeptides contain:
Over 20, less than 200 amino acids
Protein contains:
20 common and several rare (over 200) amino acids
Chemical groups in amino acids:
Single hydrogen atom
amino group
carboxyl group
side chain
Fibrous structure(eg)
Not folded (eg keratin -hair & nails)/(collagen - bones & tendons)
Globular structure (eg)
Folded (eg haemoglobin - blood)/ (enzymes)
Vitamins
Essential organic catalysts of metabolism
Catalyst
Alters rate of reaction
Vitamins we need:
A, B, C, D, E, K
What can vitamins be?
water/ fat soluble
vitamins that are water soluble
B & C
Vitamins that are fat-soluble
A, D, E, K
Sources of vitamins & benefits (eg)
C - citrus fruits, green vegetables
(fight infection & prevent sickness)
D - milk, sun
(nourishing bones)
Diseases due to vitamin deficiency
Vitamin C - scurvy
symptoms: (bleeding gums, poor healing of skin)
Vitamin D - Rickets/osteomealacia
symptoms: (weak, deformed bones that are brittle)
Example of plant mineral, location and function(2)
Magnesium:
-found in soil forms
-chlorophyll
calcium:
-found in salt in soil
-helps cell walls attach
Example of animal mineral, source and function (2)
Iron:
-found in liver, meat
-forms haemoglobin
Calcium:
-found in milk, dairy, cheese
-forms strong teeth and bones
Function of minerals:
-Form part of rigid body tissues
-Form pigments
-Regulate body fluids
Examples of pigments formed by minerals:
-Iron in haemoglobin
-Magnesium in chlorophyll
How much of cells and bodily fluids are made up of water?
70% to 95%
Physical properties of water:
-Slow to heat and cool
-good absorber of energy
-moves dissolved material in and out of cells
-controls cell shape
-strong adhesive & cohesive properties
Chemical properties of water:
-Universal solvent for transporting substances in the blood/plants
-medium for metabolism
-reactant/product in chemical reactions (e.g. photosynthesis)
Formula for photosynthesis:
Carbon dioxide + water
➡️ light/chlorophyll
➡️oxygen + glucose
Formula for respiration:
Food/glucose + oxygen
➡️
Carbon dioxide + water
Formula for glucose
CO2 + H20 ➡️ C6H12O6
Examples of anabolic reactions in plants and animals:
Plants: photosynthesis
animals: protein synthesis
Examples of catabolic reactions in plants and animals:
Plants: respiration
animal: digestion
Structural role of carbohydrates:
-Cellulose: in cell walls
-keratin: structural protein under skin, hair nails
-chitin: insect exoskeletons
Structural role of lipids:
-Waterproofs body
-protects organs
-component in cell membrane
-insulates body
Metabolic role of carbohydrates and lipids:
Primary sources of energy for metabolism
Metabolic role of proteins:
Enzymes and chlorophyll
