DNA and transcription Flashcards
what dose the process of transcription do
- process of making pre mrna from DNA
- occurs in the nucleus
what dose DNA helicasde do in transcription
breaks the hydrogen bond between the bases of a section of DNA containing a code exposis the code for the protein needed for protein sythesis
what dose RNA polyimiraise do in transcription
- moves along one of two DNA strands which acts as a template joins together free RNA nucleotide that Aline through the complementary base sequence
- cyastlyises the formation of phosphodister bonds to create a strand of pre mrna
what is splicing and why dose it need to be done
- it is turning pre mrna into mrna
- it is done as pre mrna contains introns or non coding dna
what dose degenrate code mean
each amino acid may be coded for by more than one codon
what are ribosmones made of
ribsomal rna and proteins
- 2 sub units large and small which sandwich themselves between the RNA
what is the structure of trna
- single strand of rna folded into a clover leaf shape held together by hydrogen bonds
- has an amino acid binding site
- has an anti codon 3 bases which are complementary to the codon on the mRNA that codes for an amino acid
write down the translation process
-rimbosome attaches to a start codon on the mrna
- a complementary anti codon then binds to the mrna with the amino acid
- the next anticodon then comes along and binds with the Mrna
- bibsomes catlyses condation raction to join the two amino acids together with peptide bond
- process repeated
what are the two types of mutation
deletion and substitution
what are the start codons and what do they always code for
AUG which codes for methionine
what is a haploid cell
a cell containing 1/2 the DNA of a body cell
what is a diploid cell
the cell has pairs of chromones
what happens in meiosis 1
-similar too mitosis chromosomes move to the poles of the cells
- spindle fibers form
- homologous pair line up
chromosome cross over
what is chromosome cross oerv
