Molecular Biophysics: Amino Acids and Polypeptides
18 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What replaces thymine (T) in RNA alphabet?

  • Cytosine (C)
  • Guanine (G)
  • Uracil (U) (correct)
  • Adenine (A)

    • How many bits are needed to identify a specific amino acid?

  • 5 bits
  • 3 bits
  • 4 bits (correct)
  • 2 bits

    • Which of the following is a correct structure for a phospholipid?

  • Non-polar tail + O- X X O
  • Polar head group + O CH2 CH2 N (CH3)3 (correct)
  • Polar head group + CH CH2 O P O
  • Non-polar tail + CH2 CH2 NH3+ COOH

    • What are the names of phospholipids based on the groups choline, ethanolamine, serine, and hydrogen?

    <p>Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid</p> Signup and view all the answers

    What is the main component of the non-polar (hydrophobic) tail in a phospholipid?

    <p>(CH3)3N</p> Signup and view all the answers

    How many nucleotide bases are present in DNA?

    <p>4</p> Signup and view all the answers

    Which of the following amino acids has the lowest isoelectric point (pI)?

    <p>Histidine</p> Signup and view all the answers

    In terms of side chain characteristics, which category does Glycine fall into?

    <p>Non-polar without hydrogen bond capability</p> Signup and view all the answers

    What is the pKa value of the side chain of Cysteine?

    <p>4.25</p> Signup and view all the answers

    Which amino acid has the highest relative abundance among the listed amino acids?

    <p>Glycine</p> Signup and view all the answers

    Based on side chain properties, how would Lysine be classified?

    <p>Electrically charged with ionic side chain</p> Signup and view all the answers

    What is the role of a peptid bond in protein structures?

    <p>Connects two amino acids in a protein chain</p> Signup and view all the answers

    What type of weak interactions contribute to the tertiary structure of proteins?

    <p>Ionic interactions</p> Signup and view all the answers

    Which amino acid is represented by 'ala' in the polypeptide chain ala-ala-ala?

    <p>Alanine</p> Signup and view all the answers

    What is the primary structure of a protein mainly determined by?

    <p>Amino acid sequence</p> Signup and view all the answers

    Which protein secondary structure involves hydrogen bonds between N-H and C=O groups?

    <p>Alpha helix</p> Signup and view all the answers

    In proteins, which type of bonds are known for their strength and stability?

    <p>Covalent bonds</p> Signup and view all the answers

    What is the purpose of not showing side chains (R) in the figure depicting the beta sheet secondary structure?

    <p>To avoid interference in the figure</p> Signup and view all the answers

    Study Notes

    Amino Acids

    • Lysine has a pK1' of 2.35 and a pKR of 10.53
    • L-glutamate has a pK1' of 2.19 and a pKR of 9.67
    • Amino acids can be classified into three groups based on their side chains: non-polar (incapable of hydrogen bond), polar (capable of hydrogen bond), and those with electrically charged (ionic) side chains

    Protein Structure

    • The primary structure of a protein is its amino acid sequence
    • A polypeptide chain has a specific sequence of amino acids, e.g., ala-ala-ala
    • The secondary structure of a protein refers to the specific 3D arrangement of amino acids, such as alpha helix and beta sheet
    • Alpha helix is a common secondary structure in proteins, where hydrogen bonds form between N-H groups and C=O groups
    • Beta sheet is another common secondary structure, where side chains (R) are not shown

    Tertiary Structure

    • Weak interactions between rings, including ionic, hydrophobic, and disulfide bonds between cysteine residues, help stabilize the tertiary structure
    • The tertiary structure of a protein is influenced by these weak interactions

    Quaternary Structure

    • The quaternary structure of a protein refers to the arrangement of multiple polypeptide chains in a protein
    • Polypeptide chains of different characters, possibly originating from surface charges, contribute to the quaternary structure

    Nucleic Acids

    • Nitrogen bases (nucleotides) include adenine (A), guanine (G), thymine (T), cytosine (C), and uracil (U) in RNA
    • The amount of information required to identify a specific amino acid is I = log2 20 = 4.32 bits

    Phospholipids

    • Phospholipid molecules have non-polar (hydrophobic) tails and polar (hydrophilic) head groups
    • The head group can bind to different groups, resulting in different phospholipids, such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and phosphatidic acid

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge on amino acids and polypeptides in the field of Molecular Biophysics. Questions cover topics such as lysine, L-glutamate, primary structure, and peptide bonds.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser