What is the primary function of mRNA in protein synthesis?
It carries genetic information from DNA in the form of codons.
Which type of RNA is responsible for translating the mRNA code into an amino acid sequence?
tRNA (transfer RNA).
The binding of tRNA to mRNA is based on the complementarity between a codon on mRNA and an _____ on tRNA.
anticodon
What is the role of rRNA (ribosomal RNA)?
It associates with proteins to form ribosomes, which catalyze the assembly of protein chains.
Term: Translation
The processing of mRNA into a polypeptide or protein, mediated by ribosomes.
What are the fundamental building blocks that form protein polymers?
Amino acids.
What part of an amino acid determines properties like shape, charge, and hydrophilicity?
The amino acid side chain (R group).
What level of protein structure is represented by the linear sequence of amino acids?
Primary protein structure.
The alpha-helix and beta-pleated sheet are examples of what level of protein structure?
Secondary protein structure.
What type of bond is responsible for stabilizing secondary protein structures like the alpha-helix and beta-pleated sheet?
Hydrogen bonds.
The overall three-dimensional folding of a single polypeptide chain is known as its _____ structure.
tertiary
What level of protein structure involves the assembly of multiple polypeptide chains (subunits)?
Quaternary protein structure.
When does the folding of a protein’s N-terminal domain typically begin?
While the polypeptide chain is still growing and attached to the ribosome.
The process of modifying a protein after it has been synthesized is broadly known as _____.
post-translational modification
What is the term for the initial, unfolded polypeptide chain as it emerges from the ribosome?
Nascent polypeptide chain.
According to the diagram, what is the final step in forming a mature functional protein after folding, covalent modification, and cofactor binding?
Binding to other protein subunits.
Proteins destined for secretion or to be membrane-bound are synthesized by ribosomes associated with which organelle?
The endoplasmic reticulum (ER).
What is the term for the endoplasmic reticulum that is associated with ribosomes?
Rough ER (RER).
What type of sequence do proteins destined for the ER, organelles, or secretion typically contain at their N-terminus?
A signal sequence or signal peptide.
When protein transport into the ER occurs simultaneously with translation, this process is described as _____.
co-translational
What is the simplest form of proteolytic cleavage that most proteins undergo after translation?
Removal of the first methionine residue.
What is the primary function of phosphorylation as a post-translational modification?
To regulate the biological activity of a protein.
Which type of enzyme transfers a phosphate group from ATP to a protein?
A kinase.
Which type of enzyme removes phosphate groups from a protein?
A phosphatase.
