Topic 1 - DNA + Protein Synthesis Flashcards
(33 cards)
DNA stand for?
- Deoxyribo nucleic acid
DNA structure?
- 1 DNA molecule consists of 2 strands of repeating units (nucleolides)
- 2 strands twisted into double helix
What’s the monomer of DNA?
- made up of lots of nucleotides (joined together)
- deoxyribose sugar (DNA)
-Ribose sugar (RNA)
4 DNA bases?
- Guanine + cytosine
- adenine + thymine
Purine bases?
- Adenine + guanine
Pyramidine bases?
- Cytosine + thymine + uracil
DNA is a polymer of what?
- is a polymere of mononucleotides
What reaction forms a sugar phosphate bond?
- condensation
Where do mononucleolides join together from?
- Phosphate (of one nucleotide) and phosphate group of adjoining nucleotide
- Peter to free form for diagram
A base is attached to each sugar molecule
What do sugar and phosphate units make up?
- The ‘backbone’ of the nucleic acid
Base pairing:
A strands of double helix held by what type of bonds?
Bonds between the —?
- hydrogen bonds
-Between the bases
Single hydrogen bond can be —?
Collection they can be —?
- Weak singularly
- very strong collectively
Hydrogen bonds + phosphodiester bonds
Hydrogen bonds = between bases ( nitrogenous bases)
Phosphodiester= 5’ phosphate grp (of one nucleotide) + 3’ hydroxyl grp (of another)
( check freeform for diagram)
Function of DNA?
- heredity material responsible for passing G.I from cell to cell
How DNA adapted to do it’s job?
- Stable
- strands can separate + self - replicate
- large molecule that carries lots of info
- base pairs prevents corruption from outside chemicals or physical forms
describe what happens in DNA replication:
- DNA helicase catalayses the breaks down of hydrogen bonds, and seperation of the two DNA strands
- free nucleotides join onto their complementary base pairs on template strand
- adjacent nucleotides joined by phosphodiester bonds catalysed by DNA polymerase
- Condensation reaction
What are the two parts of Protein Synthesis called?
-Transcription
-Translation
Protein synthesis
Describe what happens in Transcription:
-* mRNA is found in the nucleus*
- RNA polymerase catalyses the breakdown of hydrogen bonds, uncoiling DNA
- Template strand/anti-sense strand
- free nucleotides join onto their complementary base pairs with phosphodiester bonds. cataysed by RNA polymerase
- mRNA moves from nucleus through the pores and attach to ribosomes in cytoplasm ( site of photosynthesis)
what comes first
Translation or Transcription?
transcription then translation
Protein synthesis
Describe what happens in Translation:
- amino acids join to form polypeptide chains
- mRNA joins to ribosome on RER
- tRNA molecule with specific amino acid attached to its amino acid binding site, bind to mRNA via its anticodon
- hydrogen bonds btwn anticodon of tRNA + mRNA
- happends again- 2 amino acids form a peptide bond
- 3rd tRNA molecule joins -> first one leaves the ribosome
- process repeats forming a polypeptide chain until a stop codon is reached
name a start codon
AUG
what’s a codon?
what do they code for?
- triplet bases
- amino acids
bonds btwn amino acids?
- peptide bonds
