Nutrients Flashcards
Nutrients: Food tests, Carbohydrates, Lipids and Proteins
What molecules are always present in biomolecules?
AKA molecules that make up living things
Carbon, Hydrogen and Oxygen (sometimes Nitrogen)
What is a common property of lipids (fats)?
They do not mix well with water
What are examples of monosaccharides?
Glucose, Fructose and Galactose
What are examples of disaccharides and what are they made of?
Maltose (Glucose + Glucose)
Sucrose (Glucose + Fructose)
Lactose (Glucose + Galactose)
What are examples of polysaccharides?
Starch, Cellulose and Glycogen
Which carbohydrates are reducing sugars?
All monosaccharides and disaccharides that we learnt except sucrose
Which polysaccharide (that we learnt) is not digestable by humans?
Cellulose
What are the 3 levels of structure in proteins?
Primary: Polypeptide chain
Secondary: Alpha-helix OR Beta-pleated sheet
Tertiary: Combination of Alpha-helix and Beta-pleated sheet
Some have a quarternary structure, which is tertiary structure x2
What does an iodine test indicate?
Presence of starch
Turns blue-black: Present
Remains brown: Not present
What is the procedure of a Benedict’s test?
Mix the test solution with an equal volume of Benedict’s solution, then place in a hot (90°C) water bath for 3 min
What does a Benedict’s test indicate?
Presence of reducing sugar
Turns brick-red: Large amount
Orange-red: Moderate
Green: Trace amounts
Remains blue: Not present
What is the procedure of a Biuret test?
Mix the test solution with an equal amount of dilute sodium hydroxide, then add 1% copper sulfate solution, shaking after every drop.
What does a Biuret test indicate?
Presence of proteins
Turns purple: Present
Remains blue: Not present
What is the procedure of an Ethanol Emulsion test?
Mix the test solution with ethanol and shake, then add and equal amount of water and shake.
