Protein Structure And Synthesis Flashcards
What are proteins?
Proteins are linear chains of amino acids arranged in a 3D structural hierarchy
What are intrinsically disordered proteins (IDS)?
Proteins that have lost their native, functional folding resulting in insoluble aggression in many organs.
Causing many diseases
Structure of amino acids
Carbon, an amino group and a carbonyl functional group
How are amino acids bonded to form proteins?
Linked by covalent peptide bonds formed between carboxylic acid and amino groups of two consecutive amino acids.
How are amino acids bonded to form polypeptides?
Continuous peptide bonds between amino acids form polypeptides and the backbone of the protein.
What are the 4 levels of protein structures?
Primary
Secondary
Tertiary
Quaternary
What is a primary level of protein structure?
Unique sequence of amino acids in a polypeptide chain, with no folding.
What is the secondary level protein structure?
Stable special coils and folds of segments within a polypeptide chain.
Forms H-bond between backbone amino and carbonyl groups.
What is the tertiary level protein structure?
Three dimensional folding pattern determined by interactions among various side chains.
Stabilised by hydrophobic interactions, ionic bonds and hydrogen bonds.
What is the quaternary level protein structure?
Two or more polypeptide chain closely packed arrangement.
What changes in transcription?
DNA to mRNA
Why does transcription happen in the nucleus?
DNA is too large to leave the nucleus.
How do we produce pre-messenger RNA?
RNA polymerase uses one of the DNA strands as a template to produce pre-messenger RNA, which codes for proteins.
What are the 3 phases of transcription?
Initiation
Elongation
Termination
When does RNA processing occur?
Before pre-messenger RNA can leave to the cytosol.
Polyadenylation at 3’ end
Splices ( exons are joined together)
What changes in translation?
RNA to protein in the cytoplasm on the ribosomes.
What are tRNAs?
Adapters between codons of mRNA and the corresponding amino acid.
Ensures that the genetic code is applied.
What happens during initiation?
Ribosome gets together with the mRNA and the first tRNA.
What happens during elongation?
Amino acids are linked to form a chain.
What happens during termination?
Finished polypeptide is released.
how many hydrogen bonds are between a C-G pair?
3
how many hydrogen bonds are between a A-T pair?
2
which enzyme is responsible for denaturing DNA strands during genome replication?
helicase
what monomers are used to produce pre-mRNAs?
ribonucleotides
what monomers are used to produce proteins in translation?
amino acids
where does transcription happen?
nucleus
where does translation happen?
cytoplasm
what type of bond is formed between ribonucleotides?
phophodiester bonds
what type of bond is formed between amino acids?
peptide bonds
in what direction does the new polymer form in transcription?
5’ –> 3’
in what direction does the new polymer form in translation?
n-term –> c term
what is the difference between peptide and a protein?
peptide has less than 50 amino acids
which type of RNA contains the codon?
mRNA
which type of RNA contains the anticodon?
tRNA
which type of RNA carries the amino acids to the mRNA?
tRNA
which type of RNA is involved in the formation of ribosomal subunits?
rRNA
which region of the primary transcript is removed in the splicing reactions?
introns
