4A: DNA, RNA and Protein Synthesis Flashcards
How is DNA store in Eukaryotic Cells?
Wound around histones into chromosomes
How is DNA stored in Prokaryotic Cells?
a circular chromosome that is supercoiled to fit in the cell
What is a Gene?
a coding section of DNA that codes for a specific amino acid sequence forming a polypeptide chain
What is a Locus?
the fixed position where each gene can be found on a chromosome
What is non-coding DNA?
DNA that does not code for polypeptides called introns
Where are introns found?
Between exons in Eukaryotic DNA
What are Alleles?
different forms of the same gene
What are Homologous Chromosomes?
a pair of chromosomes that are the same size and have the same genes in the same locus
What is protein Synthesis?
the production of proteins from the information contained within a cell’s DNA
What is Transcription?
where the DNA code is copied into a molecule called mRNA
What is Translation?
where the mRNA joins with an organelle called a Ribosome and the code it carried is used to synthesise a protein
What is RNA?
a single polynucleotide strand used in Protein Synthesis
What is mRNA?
made during transcription, carries the genetic code from DNA to Ribosomes
What is tRNA?
carries Amino Acids that are used to make proteins to the Ribosomes
Describe Transciption
- mRNA associates with a ribosome / ribosome attaches to mRNA;
Idea of association is required - Ribosome moves to / finds the start codon / AUG;
- tRNA brings / carries (appropriate / specific) amino acid;
Must be explicitly stated and not inferred. - Anticodon (on tRNA complementary) to codon (on mRNA);
- Ribosome moves along to next codon;
OR
Ribosome ‘fits’ around two codons / can fit two tRNAs;
Must be explicitly stated and not inferred. - (Process repeated and) amino acids join by peptide bonds /
condensation reaction (to form polypeptide);
OR
(Process repeated and) amino acids joined using (energy from) ATP
(to form polypeptide);
