3.4.2 DNA and Protein synthesis Flashcards
What is the Genome?
Complete set of genetic information contained in the cells of an organism
What is the Proteome?
Complete set of proteins that can be produced by a cell
Describe the structure of messenger RNA (mRNA)
- Long and single stranded
- It’s DNA sequence is complementary to the DNA it was transcribed from
Suggest advantages of using mRNA rather than DNA for translation
- mRNA is shorter and contains uracil which breaks down quickly so no excess polypeptide forms.
- mRNA is single stranded and linear so ribosome will move along strand and tRNA can bind to exposed bases
- mRNA contains no introns
Describe the structure of transfer RNA (tRNA)
Single strand of about 80 nucleotides that is folded over into a clover leaf shape , on one end is an anticodon on the opposite end is an amino acid binding site.
What is produced by Transcription?
mRNA
Where does Transcription take place?
In the nucleus
What happens to mRNA after Transcription?
In eukaryotic cells: Pre mRNA undergoes splicing to remove introns which are non coding regions of DNA in order to leave the coding regions only. It then moves out the nucleus and attaches to a ribosome.
Outline the process of Transcription
DNA uncoils into 2 strands with exposed bases and one is used as a template. Free nucleotides line up next to their complementary bases and are joined together by RNA polymerase.
What is produced by Translation?
Protiens
Where does Translation take place?
In the cytoplasm (on ribosomes)
Outline the process of Translation
The anticodon of tRNA attaches to complementary bases on the mRNA. Amino acids bonded to tRNA form polypeptide bonds , continuing to form a polypeptide chain until a stop codon is reached. This process requires ATP.
