Biological Molcules Flashcards
What are the 3 polysaccharides (big ones)
Maltose, sucrose, lactose
What are the monosaccharides (small ones)
Glucose, fructose, galactose
What are the monomers of lactose
Glucose + galactose
What are the monomers of sucrose
Glucose + fructose
What are the monomers of maltose
Glucose + glucose
How do you test for protein
1) label the test tubes you are going to test for proteins
2) add 2cm3 of test solution to a test table, then add 2cm3 of water and shake
3) add ten drops of biuret solution
4) if proteins are present the solution will turn violet/ purple
What is the protein test
Biuret test
What bond holds amino acids together
Peptide bond
What is a nucleotide made up of
Pentose sugar, base, phosphate
What are the 3 key features of an amino acid
Amine group, r group, carboxyl group
Rf calculation
Distance moved by spot/ distance moved by solvent front
What is primary structure
A sequence of amino acids (polypeptide chain)
What is secondary structure
Hydrogen and disulphide bonds form between the chain causing it to coil c from beta pleated sheets or alpha helix coil
What is the tertiary structure
More coils + folds form further hydrogen, disulphide, ionic bonds
How do you test for lipids
The emulsion test
-place 2cm^3 of the sample into a test tube
-add 5cm^3 of ethanol
-shake
Add 5cm^3 of water
-shake
-cloudy white means lipids are present
In a phosphoric ehat part is hydrophobic and what part is hydrophilic
Hydrophobic-fatty acid tail
Hydrophilic- phosphate head
What is a phospholipid made up of
One phosphate group, two fatty acids, and one glycerol
What are the two types of lipid
Triglycerides and phospholipids
What bonds hold triglycerides and phospholipids together
Ester bonds
What monomer is cellulose made out of
B glucose
What monomer is glycogen made out of
A glucose
What do plants store glucose as
Starch
What do animals store glucose as
Glycogen
How do you test for reducing/ non reducing sugars
1) Mix 2cm^3 of food sample with 2cm^3 of Benedicts
2) Mix up solution and heat, if colour change is visible reusing sugars are present and non reducing ones are not
3) add another 2cm^3 of food sample to 2cm^3 of dilute hydrochloric acid
4) slowly heat up as the hydrochloric acid hydrolyses the glycosidic bonds present
5) slowly add sodium carbonate while testing with pH paper to see if the solution is alkaline
6)add 2cm^3 off denedicts and heat up solution again
7)if non reducing sugars were present the solution will now go brown form the reducing monosaccharides released
How to test for iodine
Add iodine dissolved in potassium iodide to a solution. If starch is present it will go from browny orange to gluey black
What is alpha glucose made up of
Amylopectin and amylase
