Cel 1 flashcards
what is the genome
the complete set of genes in a cell
what is the proteome
the full range of proteins a cell is able to produce
describe the structure of mRNA
carries nucleotide message fom DNA to ribosome. Linear and single stranded because carries message of one patricular gene. length of the gene. has codons.
what are codons
sequence of 3 bases in mRNA.
what is the structure of tRNA
clove leaf shaped. 80 nucleotides in size and has anticodons.
what is the function of trna
carries specific amino acids to mrna and ribosome so amino acid can be put together in order dictated to ribosome by Mrna
what is transcription
the production of mRNA from DNA
what is the role of RNA polymerase
joining mRNA nucleotides
how does transcription result in prokaryotes
directly in the production of mRNA from DNA
how does transcription result in eukaryotes
the production of premNA which is then spliced to form mRNA
What is translation
the poduction of polypeptides from the sequence of codons carried by mRNA.
describe transcription
- DNA helicase unzips DNA breaking H bonds
- RNA polymerase enables binding of complementary activated RNA nucleotides (A,U,C,G) to template strands and forms bonds in sugar phosphate backbone
- mRNA synthesis when stop triplet reached on DNA
- In prokaryotes mRNA deataches from circular DNA and travels to ribosome in eukaryotes pre-mRNA spliced into mRNA
what is splicing
splicing removes introns and rejoins extrons which can be rejoined in different orders to create different proteins
describe translation
- ribosome binds to 2 codons of mRNA at start codon
- tRNAs, carrying specific amino acids and specific anticodons
- bind to complementary codons on mRNA
- ribosome forms peptide bond between amino acids
- ribosome moves along mRNA
- codon sequence determines amino acid order
what is the function of cartilage
supports and stops trachea and bronchi collapsing
what is the function of elastic fibres
stretch and recoil
what is the function of smooth muscle
contract and relax
what is the function of goblet cells
produce mucus to trap pathogens