Extra Nucleic Acids Flashcards
What is a nucleic acid and what is it made of?
It is a polymer, made of the monomers nucleotides
How is chemical energy stored?
In lipids and carbohydrates
What enzyme breaks the bond of the 2nd and 3rd phosphate of ATP?
ATPase
How much energy is released from the breakdown of ATP?
30.6kJ
What is the bonding of ATP and Pi called?
Phosphorylation
Why is ATP more efficient than glucose?
Single step reaction, energy released immediately and in small amounts , one enzyme needed
Describe the structure of DNA
Two polynucleotides in a double helix, phosphate and deoxyribose form the backbone, complementary base pairs on the inside running antiparallel
Describe the structure of RNA
Single stranded polymer, phosphate, ribose, bases (uracil)
Describe the structure and function of mRNA
Long, single stranded . Carries genetic code from DNA to ribosomes
Describe the structure and function of rRNA
Large complex molecule, single stranded, rRNA + proteins = ribosomes
What were the 3 theories for DNA replication?
Conservative, Semi-conservative, Dispersive
Explain how conservative replication was ruled out.
Bacteria grown in N15 medium (heavy), so all bases N15, DNA spun in centrifuge, settled at bottom, bacteria in N14 medium for 20 mins, spun, control had 1 band, conservative had 2
Explain how dispersive replication was ruled out
Conservative, bacteria grown in N14 again for 20 mins, spun, control had 2 bands, dispersive had 1
Why was bacteria only allowed to grow for 20 minutes?
So it only divided once
Explain semi-conservative replication
DNA unwinds, H bonds between bases broken between by DNA helicase, free DNA nucleotides bind to complementary base pairs on the exposed strand, catalyzed by DNA polymerase, backbone forms, DNA retwists, 2 identical DNA molecules
Genetic code is …
triplet code (3 bases code for one aa), degenerate, universal (each triplet code for the same aa in all organisms), non overlapping (codes read one at a time)
What enzyme is involved in RNA splicing?
Ligase
Explain transcription
DNA helicase breaks H bonds between complementary bases, DNA unwinds, RNA polymerase links to template strand, inserting mRNA nucleotides by complementary base pairing (C-G,A-U), end of gene stop codon, RNA polymerase leaves, pre messenger RNA made, splicing, mRNA leaves through nuclear pore
What is pre - messenger RNA?
A complementary copy of the DNA template strand, once spliced becomes mRNA
Explain translocation
mRNA binds ribosome, 2 codons exposed, tRNA with complementary anticodon + specific aa activated by ATP + attracted to codon by H bonds, second tRNA binds, peptide bonds in aa, 1st tRNA releases aa + cytoplasm, ribosome moves along, repeated, stop codon, primary polypeptide, ribosome + mRNA seperate, modification
One gene one polypeptide hypothesis
