Introduction to DNA replication and protein synthesis
DNA replication and protein synthesis is a core JC1 topic in H2 BIO A levels. This topic examines DNA as one of the many types of biomolecules. In addition, we learn the process of how DNA replication occurs as well as how subsequently genes undergo transcription which produces mRNA. And the translation of mRNA forming proteins.
Useful study resources for DNA replication and protein synthesis
👆🏻 video describing the process of DNA replication
Purchase notes (including phrasing error corrections & review question solutions) for DNA protein synthesis
Most common phrasing errors students commit during exams
Leading and lagging strand synthesis occurs in opposite directions. In the leading strand, DNA synthesis occurs in the 5′ to 3′ direction, while in the lagging strand, DNA synthesis occurs in the 3′ to 5′ direction
Non-coding genes
Only mRNA is a product of transcription
A base/mRNA/gene codes for an amino acid
DNA/amino acids/genetic sequence is degenerate
DNA polymerase transcribe the second DNA strand
rRNA genes code for proteins that make up the ribosome
RNA transcription occurs first then translation of proteins next
DNA replication and transcription both occur in the 5′ to 3′ direction
Both parental strands act as template for synthesis of a daughter strand
Formation of 2 new DNA molecules consisting of 1 parental strand and 1 daughter strand
Deletion of a codon results in loss of phenyalanine production/gene lacking the amino acid
In translation, release factor binds to stop codon which will result in hydrolysis of the peptide
Consumption of GTP occurs in translation (for the translocation of ribosomes) but not in transcription and replication
Exam tips
1 DNA molecule is comprises 2 DNA strands
There is a difference between DNA unzip and unwind
There is a difference between base (nitrogenous), nucleotide, nucleoside (less frequently used)
In DNA replication, each of the 2 strands acts as a template. In transcription, only 1 strand acts as template
The triplet of 3 bases that forms the genetic code is known as the base triplet code in DNA, Codon in mRNA, Anti-codon in tRNA
The primers used in DNA replication in cells are made up of RNA nucleotides. The primers in PCR are made up of DNA nucleotides
Questions and other matters
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