biological molecules Flashcards
what are carbohydrates
made from Carbon, Hydrogen and Oxygen (CHO)
what are fats and oils
made from Carbon, Hydrogen and Oxygen (CHO)
what are proteins
made from Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulfur (CHON(S))
what are the basic units (monomers)
- simple sugars
- fatty acids and glycerol
- amino acids
what are larger molecules (macromolecules)
- starch and glycogen
- fats and oils
- proteins
test for starch
Add few drops of iodine, +ve result = blue-black colour
test for reducing sugar
Add Benedict’s reagent, then mixture is heated in water bath for 2 to 3 minutes. +ve result = brick-red precipitate, -ve result = remains blue
test for proteins
Add few drops of Biuret reagent, +ve result = mauve colour
test for fats
Emulsion test; ethanol is added to mixture, and this is poured into a test tube with an equal amount of distilled water, +ve result = milky-white emulsion
test for vitamin C
Decolourisation of DCPIP shows that a vitamin C is probably present.
what are chromosomes
Chromosomes are made of a molecule called DNA
Each chromosome is a very long molecule of tightly coiled DNA
structure of DNA
Two strands coiled together to form a double helix
what are DNA bases
Each strand contains chemicals called bases
Cross-links between strands are formed by pairs of bases
what are the DNA base pairs
The bases always pair up in the same way:
A and T
C and G
