2A:the relationship between nucleic acids and proteins Flashcards
What are nucleic acids?
Information molecules that encode instructions for the synthesis of proteins
Includes DNA and RNA.
What are the three main forms of RNA?
mRNA, rRNA, tRNA
Each type of RNA plays a specific role in protein synthesis.
What is the genetic code?
A universal triplet code that is degenerate
It consists of codons that correspond to specific amino acids.
What are the steps in gene expression?
Transcription, RNA processing, translation
These processes involve the synthesis of RNA from DNA and then translating RNA into proteins.
What are exons and introns?
Exons are coding regions; introns are non-coding regions of genes
Exons are expressed in the final mRNA, while introns are spliced out.
What is the function of the trp operon?
A simplified example of gene regulation in prokaryotes
It illustrates how genes can be turned on or off depending on the needs of the cell.
What are amino acids?
Monomers of a polypeptide chain
They combine to form proteins.
What are the four types of biomacromolecules?
Proteins, Nucleic Acids, Carbohydrates, Lipids
These are the main classes of biological macromolecules.
What forms the backbone of amino acids?
A central carbon atom, carboxyl group, amino group, R-group, hydrogen atom
The R-group varies for each amino acid.
What is a polypeptide chain?
A long chain of amino acids joined together
It is formed through peptide bonds.
What is condensation polymerization?
A process where molecules join together, losing small molecules as by-products
Used to form proteins and DNA.
What are the four levels of protein structure?
Primary, Secondary, Tertiary, Quaternary
Each level describes different aspects of protein folding and complexity.
What defines the primary structure of a protein?
The sequence of amino acids in a polypeptide chain
It determines how the protein will fold and function.
What is the secondary structure of a protein?
Arrangement into alpha-helices and beta-pleated sheets
Formed by hydrogen bonding between nearby amino acids.
What is the tertiary structure of a protein?
The overall functional 3D shape of the protein
Determined by interactions between R-groups of amino acids.
What is quaternary protein structure?
Formed when two or more polypeptide chains join together
Not all proteins have a quaternary structure.
What are prosthetic groups in proteins?
Non-amino acid groups added to proteins
Examples include glycoproteins (with carbohydrates) and lipoproteins (with lipids).
True or False: The tertiary structure of a protein forms spontaneously.
False
It requires assistance from chaperone proteins.
What is the role of chaperone proteins?
Assist in the folding of polypeptides into their functional shapes
They stabilize the protein’s structure.
What happens if the primary structure of a protein is altered?
The protein may not fold correctly, affecting its function
Changes in amino acid sequence can lead to loss of activity.
What is the proteome?
The entire set of proteins expressed by an organism at a given time
Reflects the functional diversity within an organism.
Fill in the blank: Proteins are also known as _______.
Polypeptides
This term emphasizes their polymeric nature.
What is an example of a protein with quaternary structure?
Hemoglobin
It carries oxygen in red blood cells and consists of four polypeptide chains.
What stabilizes the tertiary structure of proteins?
Hydrogen bonds and disulfide bonds
These interactions help maintain the protein’s 3D shape.
