Chapter 8 - DNA, Genes and Protein Synthesis Flashcards
(28 cards)
What are the 3 characteristics DNA possesses
- Universal
- Non-overlapping
- Degenerate
What is meant by DNA being universal
A triplet code of DNA based codes for the same amino acid in all living organisms
Eg GGT always codes for glycine
What is meant by DNA being non-overlapping
Each triplet code and gene is separate from each other, as each nucleotide/base is part of only one triplet codon
What is meant by DNA being degenerate
The same amino acid can be coded for by more than one triplet
What is meant by genome
The complete set of genes in a cell/organism
What is meant by proteome
The full range of proteins that a cell can make
What does protein synthesis consist of
Transcription and translation
In simple terms what happens in transcription
DNA is converted into mRNA
In simple terms what happens in translation
mRNA is concerted into amino acids/proteins/polypeptide
Describe DNA in eukaryotes
- Long and linear
- Double helix
- Found In nucleus
- Tightly folded around histones
- Into chromosomes
- Have introns
Describe DNA in mitochondria and chloroplasts (in eukaryotes)
- Have their own DNA
- Same structure as prokaryotes
- But have no plasmids
Describe the structure of DNA in prokaryotes
- DNA is shorter and circular
- No nucleus
- No proteins/histones
- Have plasmids (loops of DNA that are separate to main loop
- No introns, so DNA is shorter
What is meant by a gene
A sequence of DNA that codes for a polypeptide/protein
Or
A functional RNA eg tRNA
What is meant by a locus
The location of a gene in a chromosome
What is meant by DNA triplet
Sequence of 3 DNA bases that code for a specific amino acids
What does not all DNA code for proteins
There are non-coding sections
What are introns
Regions within a gene that don’t code for proteins
What’s the difference between a triplet, codon and anticodon
Triplet - DNA
Codon - mRNA
Anticodon - tRNA
What is meant by a homologous pair
Matching chromosomes
What is an allele
A different version of a gene
What is meant by splicing
Removing introns from pre-mRNA to create mRNA
Describe the full process of transcription in eukaryotes
In folder
Describe the full process of transcription in prokaryotes
Same, but no splicing as DNA goes straight to mRNA (no pre-mRNA)
What is a codon
A universal triplet of based on mRNA coding for specific amino acids
