Unit 1 KA3 - Gene expression terms Flashcards
what is gene expression?
involves the processes of translation and transcription to synthesise a protein.
what is a cell’s genotype determined by?
the sequence of DNA bases in its genes. (the genetic code)
what is the phenotype of an organism and what is it determined by?
an organism’s physical/chemical state is determined by the proteins produced as the result of gene expression
name the stages of gene expression
transcription, RNA splicing and translation.
what are introns?
long stretches of DNA within a gene that do not play a role in coding for the polypeptide about to be formed.
non-coding regions of a gene.
what are exons?
coding regions of a gene.
what is a ribosome?
site of protein synthesis.
made up of proteins and rRNA.
what are amino acids?
building blocks of protein.
linked by peptide bonds to form polypeptides.
describe how the structure of a protein is formed.
the polypetpide chains fold to form 3-D shape of a protein.
the chains are held together by hydrogen bonds and other interactions between individual amino acids.
these cross-connections are important as they cause the molecule to adopt a 3-D structure that it needs to carry out a specifc function.
what is an anticodon?
a specialised base triplet that binds to a specific mRNA codon.
Explain the three sources of variation in structure and function of proteins.
The arrangement of amino acids in polypeptide chains;
the association of more than one polypeptide chain in the mature protein;
the inclusion of non-protein structures, e.g. phosphates, metal ions, and carbohydrates.
amino acids are joined together by strong ………… bonds to form a …………… ………..
peptide, polypeptide.
