B1.2 Proteins HL Flashcards
The primary structure of a protein
The sequence of amino acids in the polypeptide chain, linked by peptide bonds.
This sequence determines the protein’s unique characteristics and functions
[True or False] Secondary protein structures are stabilized primarily by peptide bonds.
False
They are stabilized by hydrogen bonds formed between the backbone atoms
What type of protein structure is characterized by α-helices and β-pleated sheets?
Secondary structure
α-helices provide elasticity, while β-pleated sheets offer strength and flexibility.
How do tertiary structures of proteins form?
They form through interactions like hydrophobic interactions, hydrogen bonds, ionic bonds, and disulfide bridges between R groups of amino acids.
These interactions result in a complex 3D shape essential for protein function.
[Fill in the blank] Quaternary protein structures are composed of multiple __________ chains.
Polypeptide
Hemoglobin, a transport protein in red blood cells, is an example of a protein with quaternary structure.
What is the role of hydrophobic interactions in protein folding?
Hydrophobic interactions cause non-polar amino acid side chains to fold inwards, away from water, aiding in protein folding.
[True or False] All proteins have a quaternary structure.
False
Only some proteins, like hemoglobin, consist of more than one polypeptide chain and have a quaternary structure.
What type of protein is collagen and what is its primary function?
Collagen is a fibrous protein, providing structural support and stability to cells and tissues.
What distinguishes globular proteins from fibrous proteins?
Globular proteins are generally spherical and soluble in water, performing roles like enzyme action, while fibrous proteins are structural, insoluble in water, and provide support.
[Fill in the blank] The unique 3D shape of a protein, crucial for its function, is its __________ structure.
Tertiary
This structure allows proteins to interact specifically with other molecules.
What is a conjugated protein?
Conjugated proteins contain a non-protein component in addition to polypeptides.
Example: Hemoglobin with its iron-containing haem group.
[True or False] Hydrogen bonds play a crucial role in stabilizing the tertiary structure of proteins.
True
Hydrogen bonds between different parts of the polypeptide chain contribute to the stability of the tertiary structure.
What feature is common to all amino acids in a protein?
All amino acids have a central carbon atom, an amino group, a carboxyl group, and a unique R group.
How does the quaternary structure of hemoglobin facilitate its function?
Hemoglobin’s quaternary structure allows it to bind and transport oxygen efficiently through its multiple polypeptide subunits.
[Fill in the blank] Proteins that provide structural support, like tendons and bones, are typically __________ proteins.
Fibrous
These proteins are characterized by their long, stable structures, providing strength and resistance to forces.
