DNA And Protien Synthesis 4.1 Flashcards
What is a gene
-a sequence of DNA/RNA that codes for an amino acid
What is the gene locus
The specific position of a gene on a chromosome
What is an intron
A NON-CODING section of a gene
What is an exon
A coding section of DNA
What are non coding multiple repeats
Non-coding sections of DNA found between genes
Why can much of DNA be considered as non-coding
-contain non-coding repeat units between genes
-Contain non-coding introns in gene
What are the proteins that associate with eukaryotic DNA
Histones
What is a Chromosome
-A long linear strand of DNA attached to a histone
Describe the DNA in eukaryotes
-Longer and linear
-Contains introns and exons
-attached to histones
-in chromosomes
Describe the DNA in prokaryotes
-DNA is shorter
-DNA is not associated with proteins
-DNA contains exons only
-DNA in short circular loops
Describe DNA in chloroplast and mitochondria
-DNA in short circular loops
-DNA not associated with protiens
Why is genetic got described as degenerate
-Most amino acids are coded for by more than 1 triplet
Why is genetic code described as non-overlapping
-Each base is only read once
Why is genetic code described as universal
-each triplet codes for the same amino acid in all organisms
What is the genome?
All the different alleles an organism contains
What is a preotome?
-The FULL RANGE of proteins that a cell is able to produce
State the differences between and DNA nucleotide and an RNA nucleotide
DNA nucleotide:
-Contains deoxyribose
RNA nucleotide
-contains ribose sugar
( Both contains phosphate and base)
Describe the structure of mRNA
(Messenger RNA)
-straight chain
-Single chain
-Base sequence is complimentary to DNA code
-Carries ‘blue print’ from nucleus to cytoplasm
-contain codons
Describe the structure of tRNA
(Transfer RNA)
-clover leaf shape
-Carries amino acid the the ribosome
-Amino acid binding site
-Have anticodon complimentary to codon on mRNA
What is a codon?
-Sequence of three bases coding for an amino acid on mrna
What is an anticodon
-region of 3 bases
-Specific to amino acid on tRNA
-complimentary to codon on mRNA
What is pre-mRNA
-mRNA before splicing
-Contains introns and exons
What is splicing
-Introns are removed from mRNA through “splicing”(only in eukaryotes)
-Exons are joined together to produce an RNA molecule that only has coding regions in the gene mRNA passes out of the nucleus via nuclear pore
-mRNA goes to ribosome (both prokaryotes and eukaryotes)
Describe the process of transcription
-Enzyme unwinds DNA
-one strand is used as a template called the template strand
-Complimentary RNA nucleotides join with exposed DNA bases via base pairings on the template strand
U to A, A to T and C to G
Describe the process of Translation
-mRNA attaches to ribosome
-Moves to bind to start codon
-tRNA carrying a specific amino acid binds to the first codon on mRNA via complimentary base pairings with its anticodon
-Second tRNA carrying a specific amino acid binds to the first codon on mRNA via complimentary base pairings with its anticodon
- Second tRNA carrying a specific amino acid binds to the first codon on mRNA, via complimentary base pairings with its anticodon
-Enzymes join amino acids together forming a peptide bond using energy from the hydrolysis of ATP
-Ribosome moves along mRNA to the next codon
-The tRNA is lost from the first codon it no longer has an amino acid which moves away to collect another of the same amino acid
- process repeats with the addition of one amino acid (ATP required) each time untill the codon is reached
- polypeptide is releases
What is a triplet
-3 bases on a DNA molecule that code for a specific amino acid
What is a stop codon
-Marks the end of protein synthesis
