Nutrition Flashcards
Two main groups of CHO
Starch and sugar
3 groups of CHO
Monosaccharides, disaccharides, polysaccharides
Monosaccharides
Single ring of C atoms, small molecules, taste sweet, dissolve in water eg. Fructose, glucose
Disaccharides
Two rings of C atoms, small molecules, taste sweet, dissolve in water e.g. Sucrose, maltose(barley and beer), lactose
Polysaccharides
Many rings of C atoms, large molecules, dont’t taste sweet, don’t dissolve in water e.g Starch, cellulose, glycogen
Why do we eat CHO?
Energy
Carbohydrates are made by what?
plants during photosynthesis, plants capture energy from sunlight and trap it as carbohydrates
The energy in the carbohydrate molecules is released and changed into a form cells can use, what’s it called? What process is it?
ATP, respiration
Starch test
Iodine, starch turns iodine solution into a dark blue black color
Reducing sugars test
Benedict’s test, Benedict’s solution is used, color changes from blue to browinsh red when heated if positive
Proteins test
Biuret test, Potassium hydroxide is added, few drops of copper sulphate is added, if positive turns purple
Fats test
Ethanol/emulsion test, ethanol is used to dissolve fat, water is then added, tiny drops of fat form an emulsion, emulsion is a creamy white color
What are proteins made of?
Amino acids
How many amino acids are there?
20
The amino acids form different sequences following the instructions of what?
DNA
What 5 elements do proteins contain?
Carbon, hydrogen, oxygen, sulfur, nitrogen
How many essential amino acids are there?
9, body cannot manufacture them
Where is complete protein found? Why is it complete?
Animal sources because they contain all essential amino acids
Where is incomplete protein found? Why is it incomplete?
Vegetables because they don’t contain all essential amino acids
Functions of proteins
Build new cells - growth and repair, cell membranes and cytoplasm contain a lot of protein, muscle cells contain a lot of protein
Foods which contain a lot of protein
fish, lean meat, milk, yoghurt, spinach, broccoli, brazil nuts
What are fats also known as?
lipids
Fats at room temperature are known as..?
oils
What smaller molecules are fats made up of?
glycerol and fatty acids
What elements are fats made of?
Carbon, hydrogen, oxygen
Characteristics of saturated fat
single bonds between C atoms, as many H atoms as possible bonded to C atoms
Characteristics of unsaturated fat
one or more double bonds in fatty acid chain, could absorb more H atoms
What are mono-unsaturated fats?
One double bond
What are poly-unsaturated fats?
More than one double bond
What process is fat broken down by?
Respiration
Where is extra fat stored?
Under the skin
How much energy does fat contain compared to carbohydrates?
Twice as much
Uses of fat
heat insulation, prevents heat being lost from body, make cell membranes
What foods contain a lot of fat?
oil, fatty meat like sausages and bacon, butter, chips
Uses of vitamins
overall health, normal cell function, growth and development
How many essential vitamins are there?
13
What is another name for vitamin C?
Ascorbic acid
Foods which contain a lot of vitamin C
citrus fruits, kiwi fruits, red peppers, broccoli
What should you eat to make sure you have a lot of vitamin C?
Fresh fruit and vegetables
When do foods lose vitamin C?
If stored for a long time or cooked in boiling water
Uses of vitamin C
Forms collagen, keeps blood vessels strong, helps wounds heal
Deficiency disease for vitamin C
scurvy
Scurvy characteristics
skin covered in ulcers, bruises, soft gums which bleed very easily, in extreme cases teeth may fall out
Foods which contain a lot of vitamin D
fish oils (cod liver oil), egg yolks, milk, butter, margarine, oily fish (salmon, tuna, sardines, mackerel)
Vitamin D functions
Helps absorb calcium
Vitamin D deficiency disease
rickets
Characteristics of rickets
bones tend to bend into a permantently bent shape
haemoglobin
Haemoglobin is found in red blood cells, it helps transport oxygen around the body
Function of enzymes
catalysts that control the speed of metabolic reactions
Function of antibodies
made by white blood cells, help destroy bacteria and viruses that invade the body
Function of keratin
tough, insoluble protein which forms hair, nails and the outer layer of skin
Function of collagen
tough, insoluble, slightly stretchy protein found in bones and skin
Function of insulin
hormone which helps reduce blood glucose(sugar) levels
Uses of minerals
growth, development, staying healthy
What type of substances are minerals
inorganic
Where are minerals found?
soil and rocks
essential minerals are divided into two groups, what are they?
major minerals(macro-minerals), minor minerals(micro-minerals)
What is iron for?
making haemoglobin
Without enough haemoglobin, what happens?
The blood can’t carry enough oxygen around the body, without enough oxygen the body can’t do respiration and without respiration the body has less energy and feels very tired. Skin will also become pale from lack of haemoglobin.
Deficiency disease for Iron
anaemia
characteristics of anaemia
pale, tired
foods with a lot of iron
red meat (liver), spinach and broccoli, lentils and beans, nuts, seafood (oysters, mussels, clams)
Uses of calcium
makes healthy bones and teeth(makes them hard), helps blood clot
deficiency disease for calcium
rickets
foods which contain a lot of calcium
milk, yoghurt, cheese, spinach, broccoli
Uses of water
- Good solvent - allows many different substances to dissolve in it - many metabolic reactions take in cytoplasm, reactions only take place when chemicals are dissolved in water, person loses too much water, reactions may stop, person dies
- Solvent to transport substances around the body - blood plasma is mainly water with many substances dissolved in it - hormones, amino acids, glucose, vitamins, antibodies - waste substances; CO2, urea - red and white blood cells float in blood plasma
- take part in many chemical reactions - water is needed to break down molecules in digestive system
- the evaporation of water in sweat helps cool us down
What does the amount you eat depend on?
- age
- sex
- occupation and physical activity
- pregnancy and lactation
- illness and injury
What is the energy in basal metabolism used for?
heary lungs and digestive system working normally - maintains nerve impulses to and from the brain and chemical reactions
Other energy (not used for basal metabolism) is used for..?
muscles, physical work, posture
What happens during starvation?
- Person uses all stores of fat
- Person loses weight, becomes thin
- uses tissue protein (particularly muscles) for energy
- muscles become small and weak
- bones cannot grow
- death occurs around 60 days
Deficiency disease for protein
kwashiorkor
Characteristic of kwashiorkor
‘pot belly’ from infiltration of fat in the diet
People who are obese are more likely to suffer..?
varicose veins, diabetes, gall stones, high blood pressure, complications during surgery, heart disease
Saturated fat is found in..?
fatty meat (sausages, bacon, burgers), cakes and pasteries, butter and cream, ice-cream and chocolate
Polyunsaturated fat is found in..?
olive oil, sunflower oil, salmon, mackerel, sardines
What can eating to much salt cause?
high blood pressure, heart disease, strokes
What does adding fat to a food cause?
increases energy content
What low energy sugar substitute should you use and why?
saccharin because it reduces energy value in drinks and dishes but still tastes sweet
Why should you eat foods with high proportions of water
low in energy because water yields no energy
What are the 4 main additives and their uses?
Preservatives - keep food fresh
antioxidants - keep food components from mixing with oxygen (can cause discoloration and spoil the taste)
flavourings and colorings - add to appearance and tatse of food
stabilisers - stop foods like ice-cream from seperating into watery and fatty components
