NUTRIENTS (Proteins (amino acids are its building blocks (they are…
are organic molecules made up of the same elements carbon, hydrogen, oxygen and nitrogen too. Another element, sulfur, may also be present.
proteins must be broken down in the body because its molecules are too big to pass through living cell membrane
- add 2cm cube of sodium hydroxide to 2cm cube of egg white solution in a test tube and shake it throughly
- add 1% of copper sulfate solution drop by drop and shaking it after every drop
- observe what does colour changes to
it will turn violet if proteins are present
What are the functions of proteins?
-synthesizes of new protoplasm
- synthsises of new enzymes
-formation of antibodies
they are organic molecules made up of the elements carbon , hydrogen and oxygen but their fats contain much less oxygen to hydrogen
What are some of the functions of fats
-A source of energy
- an insulating material that prevent heat loss
-an essential part of protoplasm
What are the sources of fats?
-foods that are rich in fats includes butter , cheese , fatty meat , olives and many more.
How can we identify fats?
-A cloudy white emulsion will appear when ethanol and water are added to fats
Ethanol emulsion test
*on liquid food
-Add 2cm cube of ethanol to a drop of coconut oil in a test tube and shake it
-add 2 cm cube of water to the mixture and shake it.
Are organic molecules made up of elements carbon , hydrogen and oxygen. The hydrogen and oxygen atoms are presented in the ratio 2:1
Disaccharides (single sugars)
They all have the same chemical formula and they can pass through the cell membrane because they are small molecules.
*Each molecule of the double sugars are made up of two molecules of single sugars.
- They have the same chemical formula hence their atoms are arranged differently.
GLUCOSE + GLUCOSE <condensation reaction> = MALTOSE + WATER
-A condensation reaction is a chemical reaction when 2 simple sugars combined together to form a larger molecule with the removal of water molecule.
MALTOSE + WATER<HYDROLOTIC REACTION> = GLUCOSE + GLUCOSE
-A hydrolytic reaction is a reaction in which a water molecule is needed to break up a complex molecule into smaller molecules.
Testing for reducing sugars
- Glucose , fructose , galactose , maltose and lactose are reducing sugars .
- the colour brick red will appear to show if that substance or sample has reducing sugars in it.
- The experiment is called " Benedict's test"
1) place 2cm cube of food sample into a test tube
2) add 2cm cube of benedict's solution to the food sample
3) place it in a boiling water bath for 3 minutes.
- they consist of many monosaccharides joining together.
Why glycogen and starch are suitable as storage materials in cells?
- insoluble in water
- they are large molecules which cannot fit in the cell membrane
What are some of the functions of carbohydrates ?
- as a substrate for respiration
- to form supporting structures
- for the formation of nucleic acids for example ; DNA.