Section of DNA that contains the coded information for making polypeptides and functional RNA
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Why is the genetic code 'degenerate'?
Most amino acids are coded for by more than one triplet
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Why is the genetic code universal?
Each triplet codes for the same amino acid in all organisms
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What are introns and exons?
Exons are coding sequences, introns are non-coding sequences between exons
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What is the difference between DNA in eukaryotic and prokaryotic cells?
Eukaryotes have longer linear DNA, associated with histone proteins. Prokaryotes have short circular DNA with no proteins.
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What is the structure of a chromosome?
DNA molecules highly coiled around histones. Two thread like structures called chromatids joined at the centromere.
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What is a homologous pair?
Two chromosomes that carry the same genes but not always the same alleles
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What is an allele?
One of a number of alternative forms of a gene
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What is the function of mRNA?
Transfers the DNA code from the nucleus to the cytoplasm
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What is the genome?
Complete set of genes in cell
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What is a proteome?
Full range of proteins produced by the genome
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Describe the structure of RNA
Pentose sugar, organic bases adenine & uracil, cytosine & guanine, and phosphate group
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Describe the structure of mRNA
Long strand in a single helix. Base sequence determined by sequence of bases on DNA in a process called transcription
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Describe the structure of tRNA
Single stranded chain folded into clover shape. One end of chain extends beyond others so specific amino acid can attach and anticodon is specific too
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What happens to the anticodons in protein synthesis?
Pair with three complementary organic bases that make up codon on mRNA
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Describe the process of transcription
DNA strands separate exposing bases. Bases on template strand find complementary pairs. RNA polymerase joins nucleotides to form pre-mRNA, and keeps going until it reaches 'stop' code
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What is splicing of pre-mRNA?
Removing base sequences corresponding to introns then joining functional exons to form mRNA
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How are proteins assembled?
Polypeptide coiled/folded (secondary), folded further (tertiary), more polypeptide chains & non-protein groups linked (quaternary)
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Describe protein synthesis
DNA sequence of triplets determine codon sequence on mRNA, which determines order tRNA lines up in. Determines sequence of amino acids in polypeptide, protein and enzymes
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Other cards in this set
Card 2
Front
Why is the genetic code 'degenerate'?
Back
Most amino acids are coded for by more than one triplet
Card 3
Front
Why is the genetic code universal?
Back
Card 4
Front
What are introns and exons?
Back
Card 5
Front
What is the difference between DNA in eukaryotic and prokaryotic cells?
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