Biological molecules part 2 Flashcards
can you draw the general structure of amino acid ?
can you draw alpha and beta glucose ?
can you draw basic structure of triglyceride and phospholipid and show their formation ( condensation reaction)
primary structure of a protein determines what ?
the location of the ionic, hydrogen and disulphide bonds present in the tertiary structure. location of bond determines how protein folds and the 3D shape
How do you carry out the test for proteins ?
- Add biuret solution to food sample
- positive test observation: solution turns from blue to purple
How to test for lipids ?
- dissolve sample in ethanol and shake
- add distilled water
- a positive test observation: white emulsion forms
Draw the structure of DNA nucleotide
How does DNA replicate ?
through process of semi-conservative DNA replication
What does semi-conservative DNA replication mean?
in the daughter DNA one strand is from the parent and one strand is newly synthesised
What are the two enzymes involved in DNA replication ?
DNA helicase and DNA polymerase
Describe the process of DNA replication ( parental DNA into daughter DNA)
- DNA helicase breaks the hydrogen bonds between the complementary base pairs. this causes DNA double helix to unwind
- each of the separated strands acts as a template strand. free floating DNA nucleotides attract to their complementary base pairs on temp strands
- DNA polymerase catalyses the joining together of adjacent nucleotides to form phosphodiester bonds. joined together by a condensation reaction
- now we have 2 DNA daughter strands which contain one original strand and one that has been newly synthesised
What is meant by conservative DNA replication?
original DNA remains intact and the two newly synthesised strands of DNA join together
How will the isotope of nitrogen in which the bacteria are grown in affect the position of band of DNA ?
- bacteria grown in a medium containing 14 N nitrogen will have DNA that only contains that isotope and be lighter. The 15N growth medium will result in heavier DNA
- position of DNA band will be higher up when it is lighter and lower down when heavier.
How can the density of the DNA be confirmed ?
samples can be spun in a centrifuge
