DNA and protein synthesis Flashcards
What is the difference between eukaryotic and prokaryotic DNA?
Prokaryotic: Shorter, circular, aren’t associated with proteins
Eukaryotic: Longer, linear, associated with proteins called histones which form chromosomes
Mitochondria/chloroplasts: Contain DNA which is like the DNA of prokaryotes
Gene definition
DNA base sequence that codes for polypeptides or a functional RNA
Allele definition
An alternative form of a gene
What are sections of non-coding DNA called?
Introns
What is the triplet code?
3 DNA bases (triplet) code for 1 amino acid
Degenerate definition
Most amino acids are coded for by more than one triplet
Non-overlapping definition
Each base is only read once
Universal definition
Each triplet codes for the same amino acid in all organisms
Genome definition
All the DNA in a cell
Proteome definition
The whole range of proteins that a cell is able to produce
What is the difference between mRNA and tRNA?
mRNA: Linear shape, has codons
tRNA: Clover leaf shape, has anticodons
What does tRNA contain?
Anticodons, amino acid binding site
What does transcription do?
DNA –> mRNA
What are the 4 steps of transcription?
- Hydrogen bonds between 2 strands are broken so DNA strands separate
- 2 strands used as template strands
- Complementary free RNA nucleotides join with exposed DNA bases via base pairing on template strand
- RNA polymerase joins adjacent nucleotides via phosphodiester bonds
What does splicing do?
*Removes introns from pre-mRNA so mRNA molecule only has coding regions
*mRNA passes out of the nucleus via a nuclear pore and goes to a ribosome
*Doesn’t occur in prokaryotes