Proteinsynthesis Flashcards
what is proteinsynthesis
process of making proteins where amino acids are linearly arranged to fold into complex proteins
describe the process of proteinsynthesis in the transcription stage
- RNA polymerase attaches to start codon
- separates double helix structure
- polymerase moves along gene making a strand of mRNA out of free bases in nucleus
- uses coding DNA in the gene as a template to make the mRNA
- base pairing between DNA and RNA ensures the mRNA is complementary to the gene
- mRNA processed by adding and deleting sections of RNA
- mRNA moves out of nucleus into cytoplasm where it joins with a ribisome
- process is transcription
what nucleotides match up in proteinsynthesis
C and G
A and T
what happens when RNA places a complement to an ‘A’ on the DNA template
- it complements it with a ‘U’ for uracil
- RNA uses uracil instead of thymine
what effect does the order of bases in a gene have
it decides the order of amino acids in a protein
what are the parts of dna that dont code for proteins responsible for
- switching genes on and off so they control whether a gene is expressed or not
- this is used to make specific proteins from controlling the start and end codons and what genes compose an amino acid to create the protein
where are proteins made
in the cytoplasm on tiny structures call ribisomes
why is mRNA used to make proteins instead of using the DNA itself
because dna in the nucleus of cells cant move out as they are too big
how does mRNA act like a messenger
- because it carries the code copied from the dna to the ribisome
- its the method in which they communicate
list some examples of proteins that are made from proteinsynthesis
- enzymes
- hormones
- structural proteins
what is the role of an enzyme
acts as a biological catalyst to speed up chemical reactions in the body
what is the role of hormones
to carry messages around the body through the blood
what is the role of structural proteins
- theyre just physically strong so theyre used as building blocks
- collagen is a structural protein that strengthens connective tissue
what are proteins made up of
chains of amino acids in a polypeptide bond
how are proteins made from amino acids
the chain of amino acids fold up to create a complex 3D structure
what is the significance of the randomness o how the chain of amino acids fold
- it gives each protein a different and specific shape
- meaning each protein has its own different function
how are particular proteins coded for
- each gene contains a different sequence of bases
- which is what allows it to code for a different protein
what is RNA polymerase and what is its function
- RNA polymerase is an enzyme
- it is involved in joining together RNA nucleotide to make mRNA
describe the process of proteinsynthesis in the translation stage
- ribosomes bind to start codon on mRNA
- ribosome reads mRNA 3 bases at a time to produce amino acids
- tRNA carries the corresponding amino acids to ribisomes
in the order mRNA is read - added to growing chain of amino acids with peptide bonds
- polypeptide chain of amino acids fold into complex 3D shape to form protein when last amino acid is added
what does the order in which the amino acids are brought to the ribosome match in proteinsynthesis
the order of the base triplets in the mRNA (in other words, codons)
what is an anticodon and what is part of
- anticodon is part of the tRNA
- it is complementary to the codon for the amino acid
- the pairing of the codon and anticodon makes sure that the amino acids are brought to the ribosome in the correct order
how can non coding regions still affect the phenotype of an organism
- RNA polymerase binds to the region of non coding DNA in front of a gene
- if mutation happens, it could affect the ability of RNA polymerase to bind to it
what does how well RNA polymerase can bind to the non coding part of DNA affect
- how much mRNA is transcribed
- and therefore how much of the protein is produced
- depending on the function of the protein, the phenotype of the organism may be affected by how much is made
what is the role of transfer rna
to bring the amino acids to the ribosome
