Biological Molecules Flashcards
What is a monomer?
Give some examples
Monomer = small sub unit that firms larger molecules
e.g. monosaccharides, amino acids, mononucleotides
What is a polymer?
Give some examples
Polymer = multiple monomers joined together
e.g. polysaccharides, protein, DNA
What reaction occurs when 2 monomers join together to form a polymer?
Condensation reaction
What’s a hydrolysis reaction?
When a chemical bond is broken down between 2 molecules using water
Name 3 structures and functions of starch
insoluble = no osmosis occurs
large = don’t diffuse out of cells
H bonds = compact
Name 3 structures and functions of glycogen
branched = terminal end for hydrolysis
insoluble = no osmosis or diffusion occurs
1,4 + 1,6 glycosidic bonds = compact
Name 3 structures and functions of cellulose
straight, unbranched molecule
H bonds link myofibrils = high tensile strength
1,4 glycosidic bonds
Describe Benedict’s test for reducing sugars
- Add equal vol. Benedict’s reagent to sample
2.Heat in water bath for 5 minutes - +ve result = blue –> brick red ppt.
Describe Benedict’s test for non-reducing sugars
- -ve result = sol. remains blue
- Hydrolyse non-reducing sugar + heat in water bath for 5 minutes
- Neutralise mixture with sodium carbonate
- Proceed with Benedict’s test with same outcome
Describe the test for starch
- Add iodine
- +ve result = orange –> blue-black
Describe the test for lipids
- Add ethanol + shake
- +ve result = cloudy white ppt
How are triglycerides formed?
Condensation reaction between 1 glycerol and 3 fatty acids (forms ester bonds)
What’s the difference between a saturated and unsaturated fatty acid?
Saturated contain only single bonds
Unsaturated contain C=C double bonds
Describe the structure and function of phospholipids
Hydrophilic phosphate head
Hydrophobic fatty acid tails
Form a bilayer
Why is water a polar molecule?
Forms from delta -ve O and delta +ve H
O is more EN than H