DNA and protein synthesis Flashcards
what is a genome
the complete set of genes in a cells including those in mitochondria and or chloroplasts
what is a proteome
the full range of proteins that a cells/ genome is able to produce
what is an allele
different version of the same gene
what is a homologous pair of chromosomes
same size chromosomes with same genes but different alleles
what are the two stages of protein synthesis
transcription - production of mRNA from DNA
translation- production of polypeptides from the sequence of codons carries mRNA
describe mRNA
messenger RNA
made by transcription in nucleus
acts as a template in translation in cytoplasm
straight chain molecule
sequence of bases in RNA determine squeeze of amino acids in polypeptide
sequence of bases in RNA determined by sequence of bases in DNA - triplet code
chemically unstable so breaks down after a few days
describe tRNA and draw with labels
transfer RNA
caries an amino acid - amino acid binding site
anticodon - 3 bases complementary to mRNA codon
east tRNA is specific to one amino acid in relation to its anticodon
clover shape help by hydrogen bonds
clover leaf shape with amino acid binding site, t loop, anticodon loop, anticodon, d loop
what are similarities and difference between mRNA and tRNA
similarities
- both single polynucleotide stands
differences
- mRNA is single helix/straight, tRNA folded into clover shape
- mRNA is longer where tRNA is shorter
- mRNA contains no paired bases or hydrogen bonds, tRNA has some paired bases and hydrogen bonds
describe the process of transcription
in nucleus
DNA double helix unzipped by helicase - hydrogen bonds broken
RNA nucleotides align next to complementary bases on template
RNA polymerase joins adjacent nucleotides in condensation
forming phosphodiester bonds
when RNA polymerase reached stop codon mRNA or pre-mRNA detaches from DNA
mRNA leaves via nuclear pores
splicing removes introns from pre-mRNA and exons spliced together in eukaryotes
describe the process of translation
sequence of mRNA codons determines sequence of amino acids
tRNAs carry specific amino acids in relation to their anticodon
at the ribosome tRNA binds to mRNA codon
two amino acids joined hh condensation forming a peptide bond using ATP
tRNA detaches ribosome moves along mRNA to next codon
continue until stop codon
what is the role of ATP in translation
hydrolysis of ADP to ADP and Pi releases energy
for the bond between the amino avid and it corresponding tRNA molecule - amino acid attached to binding site
for peptide bond formation between amino acids
what is the role of tRNA in translation
attached to and transports specific amino acid in relation to anticodon which is complementary to base pairs to mRNA codon forming hydrogen bonds
two tRNAs being amino acids together for formation of peptide bond
about 60 types of tRNA to carry 20 amino acids - genetic code is degenerate
what is the role of ribosomes in translation
attached to mRNA and houses tRNA allowing codon-anticodon complementary base pairing
allows peptide bonds to form between amino acids
how would you relate base squeeze of nucleic aid to amino acid sequence of polypeptides when provide with data
tRNA anticodons are completely to mRNA condone eg. ACG and UGC
mRNA sequence of bases are complementary to swine e of bases on DNA template strand
in RNA uracil replaces thymine
