DNA Replication
What is a semi-conservative process / What is DNA replication?
Process in which one strand will be from the original template molecule and one strand will be newly synthesized
What is transcription?
Using DNA as a template for mRNA
What are nucleic acids?
The genetic material of the cell and are composed of recurring monomeric units called nucleotides.
What is the genetic code?
The set of rules by which information encoded within mRNA sequences is converted into amino acid sequences (polypeptides) by living cells.
What is the helicase?
Unwinds the double helix and separates the two polynucleotide strands; does this by breaking the hydrogen bonds that exist between complementary base pairs
How many different types of RNA are there and name them?
mRNA, tRNA, rRNA
What does non-coding DNA do?
What three things make up a nucleotide?
Phosphate group, sugar and nitrogenous base
Where are amino acids joined together to make polypeptides?
What do the DNA polymerase I and III do?
Polymerase I unbinds the RNA primer and replaces it with DNA nucleotides
Polymerase III synthesizes new strands from the two parental template strands; cleaves the two excess phosphates and uses the energy released to link the nucleotide to the new strand
On which stand does transcription occur?
Antisense, so that the strand makes sense
What happens in the promotor section?
A repressor can bind to stop the transcription or a transcription factor can join to enhance transcription
Who are James Watson and Francis Crick?
The scientists who won a nobel prize for the discovery of the structure of DNA
initiation, elongation, and termination
What are Okazaki fragments?
Okazaki fragments are short, newly synthesized DNA pieces formed discontinuously on the lagging strand (3 - 5) during DNA replication.
What enzymes are needed in transcription
RNA polymerase
To RER
What is the four differences between DNA and RNA?
1. Sugar (deoxyribose and ribose)
2. Bases (U and T)
3. Strands (double and single)
4. Length (short and long)
Why is DNA degenerate?
DNA is degenerate as more than one codon corresponds to an amino acid and therefore mutation will affect DNA less.
By growing E. coli in heavy Nand switching to light N, they used density gradient centrifugation to track the DNA, finding a hybrid intermediate density after one generation that confirmed this model
Outline the stages in the production of mRNA by transcription.
a. DNA is unwound/strands are separated «by RNA polymerase»
b. new nucleotides attached to template strand «by RNA polymerase»
c. complementary base pairing/base pairing
d. mRNA detaches from template
e. DNA rewinds
Explain what happens to proinsulin?
roinsulin is synthesized in RER due to the signal sequence. This is spliced off after traslation is complete. Proinsulin is then transported to the golgi apparatus. Connecting segment is spliced in the golgi and the two remaining segments are foleded and joined by disulphide bonds - STORED IN VESICLES
How does the DNA condense? Draw it on the board
EPA