Biological molecules Flashcards
1
Q
Carbohydrates
A
- Monosaccharide -> C6H12O6
- Disaccharide -> C12H22O11
- Polysaccharide -> ( C6H10O5 ) n
2
Q
Benedict’s test
A
- Blue solution
- 2cm3 of food sample
- 2cm3 of solution added
- Boil mixture at 80-90^C for 2mins
- colour change from blue -> green -> yellow -> orange -> brick red if reducing sugar is present
3
Q
Iodine test
A
- add few drops of iodine to food sample
- ## turns blue black if starch is present
4
Q
Ethanol emulsion test
A
- 2cm3 of oil in test tube
- 2cm3 ethanol added
- 2cm3 water then added
- solution is shaken
- cloudy white emulsion is formed
5
Q
Biuret test
A
- 2cm3 food sample
- 2cm3 NaOH added
- few drops of dilute CuSO4
- Mixture is shaken
- Violet/ purple colour obtained if protein is
present - Mixture remains blue if absent
6
Q
What is a nucleotide made of
A
- a pentose sugar ; 5 carbon ( deoxyribose )
- a nitrogen-containing base
- a phosphate group ; from phosphoric acid
7
Q
What are the 4 types of nitrogen-containing bases
A
1) Adenine ; A
2) Thymine ; T
3) Guanine ; G
4) Cytosine ; C
A&T ; G&C
8
Q
DNA structure
A
- many nucleotides join together to form a polynucleotide
- 2 polynucleotide chains twisted to form a double helix
