DNA, RNA and Protein Synthesis Flashcards
How is DNA stored in eukaryotes?
-Wound around histone proteins
-DNA and histone protein are coiled up tightly to make a chromosome
What is a genome?
-The complete set of genes in a cell
What is a proteome?
-The full range of proteins that the cell is able to produce
What are introns?
-Sections of a polypeptide that don’t code for amino acids
What are exons?
-Sections of a polypeptide that do code for amino acids
What is an allele?
-A form of a gene
What is mRNA?
-Transcription
-Made during transcription
-Carries genetic code from the DNA to the ribosomes
-Single polynucleotide strand
What is tRNA?
-Translation
-Carries the amino acids to ribosomes
-Single polynucleotide strand folded into a clover shape
-H bonds between specific base pairs hold the molecule in the shape
-Anticodon
-Amino acid binding site
Describe the process of transcription
-RNA polymerase attaches to DNA at the start of a gene
-H bonds between two strands are broken by DNA helicase
-RNA polymerase lines up free nucleotides along exposed bases on template strand
-CBP
-Complementary mRNA strand made
-RNA polymerase moves along DNA, H bonds reform, strands recoil
RNA polymerase reaches stop signal and detaches
-mRNA moves out of nucleus and attaches to ribosome
Describe the process of translation
-mRNA attaches to ribosome and tRNA molecules carry amino acids to it
-tRNA molecule, with anticodon, attaches to mRNA by CBP
-Second tRNA molecule attaches itself to the next codon
-Two amino acids joined by peptide bond
-First tRNA molecule moves away, leaving the amino acid behind
-Process continues until there is a stop signal
What is the genetic code?
-The sequence of base triplets in mRNA which code for a specific amino acid
What does non-overlapping mean?
-Codons don’t share bases
What does degenerate mean?
-More possible combinations of triplets than amino acids, so some amino acids are coded for by more than one codon
What does universal mean?
-The same specific base triplets code for the same amino acids in all living things