Protein Structures and Functions

A set of flashcards reviewing key concepts about protein structures and functions, essential for understanding their roles in biological systems.

What are the major classes of proteins?

1. Fibrous proteins 2. Globular proteins 3. Membranous proteins 4. Intrinsically disordered proteins (IDPs)

What characterizes fibrous proteins?

Fibrous proteins have long strands or sheets, are generally insoluble in water, and feature simple repetitive motifs.

What is the basic structure of collagen?

Collagen is made of helices but not alpha-helices, and consists of three helical chains that make a super twist with a right-handed helicity.

What is the structural unit found in globular proteins?

A motif or fold, which is a structural unit that contains at least two secondary elements.

How does the hydrophobic effect influence protein folding?

The hydrophobic effect is the major driving force for the folding of globular proteins.

What is the term for proteins made of multiple subunits?

Oligomers.

What is protein denaturation influenced by?

Temperature, pH extremes, high salt concentrations, and high concentrations of denaturing agents.

What role do chaperones play in protein folding?

Chaperones assist in the folding of proteins that cannot fold spontaneously and help refold partially unfolded proteins.

What defines intrinsically disordered proteins (IDPs)?

IDPs lack hydrophobic amino acids and are often rich in charged amino acids.

What is proteostasis?

Maintaining a set of proteins in their functional condition, including processes like protein synthesis, folding, and degradation.

How are disulfide bridges relevant in protein stability?

Disulfide bridges stabilize protein tertiary structures and can be reduced to restore the original structure.