DNA In Cells Flashcards
What are the three steps to creating DNA?
1) Protein synthesis
2) Transcription
3) Translation
What is transcription?
Transcription is when information in a strand of DNA is copied into a new molecules of messenger RNA (mRNA) by using RNA polymerase and RNA nucleotides.
What are the three main steps of translation?
1) Initiation
2) Elongation
3) Termination
What is a sense and missense strand of DNA?
A sense (coding strand) is a strand of DNA is the segment within a double-stranded DNA that carries the translatable code which is complementary to the antisense (template strand) strand of DNA.
How enzymes contribute to transcription?
The enzyme that aids transcription is called RNA polymerase. RNA polymerase link nucleotides to form a RNA strand which forms mRNA.
What is translation?
Translation is the decoding of instructions for making proteins.
What is Initiation?
It is the beginning stage when small subunits of ribosome bind to the mRNA sequence and the tRNA start codon and anticodon bind to the ribosome.
What is Elongation?
Elongation is when RNA get longer due to the addition of new nucleotides. Amino acids are brought to the ribosome by tRNA and linked together to form a polypeptide chain.
What is Termination?
Termination is the end of transcription and occurs when RNA polymerase cross a stop (termination) code in the gene. The polymerase has transcribed a DNA template.
The release factor (type of enzyme) attaches onto the stop codon and creates a water molecule.
What are codons and anticodons?
Condon are trinucleotide units in mRNA that codes for an amino acid.
Anticodon are trinucelotide units in tRNA that is complementary to the codon in mRNA.
What is the role of Codons?
Codons transfer genetic information from the nucleus to the ribosomes where protein synthesis takes place.
What are three types of RNA?
1) mRNA— carry the coding sequence for transcription
2) tRNA— molecules carry amino acids to the ribosomes during protein synthesis.
3) rRNA— molecules from the core of a cell’s ribosome (structure where protein synthesis happens)
What are polysomes?
Many ribosome transcribe the same mRNA so many copies of the same protein can be made. The clusters of ribosomes are called polysomes.
What is helicase?
Helicase is the enzyme that “unzips” a molecule of DNA at their origins (genomic regions where DNA replication starts) by breaking the hydrogen bonds between base pairs and unwinding the two strands of the molecule.
What is a release factor enzyme?
A release factor is a protein that allows for the termination of translation by recognizing the termination codon or stop codon in an mRNA sequence.
