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