18 Questions
When hydrogen bonds are formed between the polypeptide backbones of separate polypeptide chains, what are they called?
Interchain bonds
What type of structure is primarily found in the core region of globular proteins?
A combination of α-helices, β-sheets, and nonrepetitive sequences
What is the arrangement of N-terminal and C-terminal ends of β-strands in an antiparallel β-sheet?
Alternating
In a β-sheet formed by a single polypeptide chain folding back on itself, what type of hydrogen bonds are present?
Intrachain bonds
Which structural elements are usually adjacent in the final folded protein due to packing side chains close to each other?
α-helices and β-sheets
Which type of β-sheet arrangement involves all the N-termini of the β-strands together?
Parallel arrangement
What type of structures are the α-helix and β-sheet in proteins?
Secondary structures
Which part of the peptide bond is involved in hydrogen bonding in proteins?
C=O and NH groups
Which family of proteins has a nearly entirely α-helical structure and is a major component of hair and skin?
Keratins
What type of bonds stabilize an α-helix in proteins?
Hydrogen bonds
Which characteristic determines the rigidity of keratins found in hair and skin?
Number of disulfide bonds between polypeptide chains
What is the term used to describe regular arrangements of amino acids located near each other in the linear sequence of a polypeptide?
Secondary structure
Which type of secondary structure involves peptide bond components that are all involved in hydrogen bonding?
Globular structure
How many amino acids are present in each turn of an α-helix?
3.6 amino acids
What do hydrogen bonds do collectively to the helix?
Stabilize
In which type of secondary structure are the peptide chains almost fully extended?
β-sheet
Which type of secondary structure involves peptide bond components linked to each other through intrachain hydrogen bonds?
β-sheet
What is the relationship between amino acid residues spaced three or four residues apart in the primary sequence when folded in an α-helix?
They are spatially close together
Test your knowledge on the arrangement of beta-sheets and polypeptide chains in proteins. Learn about the differences between parallel and antiparallel β-sheets and how hydrogen bonds contribute to their stability.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
