Amino acid residues - Study guides, Class notes & Summaries

BCHM 307 EXAM 1 QUESTIONS WITH ANSWERS Secondary structure - Answer-the local 3-dimensional structure of the peptide backbone - there are 4 major classes of secondary structure (alpha helix, beta sheet, turns, and random coil) The alpha helix of the secondary structure - Answer-the alpha helix is a helical region of the peptide backbone that is stabilized by hydrogen bonding - carbonyl residue of each amino acid residue is hydrogen bonded to the amide group 4 residues further toward the c...

Which of the following differentiates the biochemical standard state from the standard state when discussing standard free energy changes? correct answers pH of 7 If a typical person hydrolyzes 100.0 mol of ATP per day, how much does this ATP weigh? (The molecular weight of ATP is 507 g/mol.) correct answers 50.7 kg A reaction is always spontaneous if correct answers the change in free energy, ΔG, is negative. Which of the following is an example of a heterotroph? correct answers yeast...

Typical Van der Waals energies are about: correct answers 2-4 kJ/mol A possible drug to treat COVID-19 has been discovered and is known to be a weak acid. At the pH of blood (7.4) the concentrations of acid and conjugate base are 0.075 and 0.025 respectively. What is its pKa? correct answers 3.00 What is the [A-]/[HA] ratio whent he weak acid is in solution alone pH unit above its pKa? correct answers 10:1 What are the primary chemical components present in a phosphate buffer at pH 7.4?...

Types of Proteins - ANSWER-o Cellular / nuclear o Integral membrane, membrane-anchored, membrane-attached o Extracellular / secreted Examples of proteins - ANSWER-Collagen, Hormones, Receptors - cell surface/nuclear, Enzymes, Transporters, Channels, Cytoskeleton, Motor proteins / transport, Antibodies, Neuropeptides, Transcription factors, Chaperones, Histones, Binding proteins primary protein structure - ANSWER-Linear sequence of amino acid residues joined through peptide bonds to form ...

Which of the following amino acid would not be commonly found in the middle of a an α-helical domain? - Proline. It is considered a 'helix breaker' and would not be found in an alpha helix; all other residues are nonpolar hydrophobic and could reside in a transmemebrane domain. Changes in the physiological variables listed below can alter the affinity of hemoglobin for oxygen. Which of the following will lower the affinity of hemoglobin for oxygen? a) decrease in protons b) increase in...

Nucleic acids stain with ______ dyes which impart a ________ color. Therefore, nucleic acids are described as ______. A. Base-like; blue/purple; acidophilic B. Acid-like; red/pink/orange; basophilic C. Base-like; blue/purple; basophilic D. Acid-like; red/pink/orange; acidophilic - Answer-C. Base-like; blue/purple; basophilic Which molecules are lost from cells during the processing for H&E staining? a. Carbohydrates b. Proteins c. Lipids d. Nothing is lost - Answer-c. Lipids A slide-m...

Henderson-Hasselbach Equation - pH = pKa + log ([A-] / [HA]) FMOC Chemical Synthesis - Used in synthesis of a growing amino acid chain to a polystyrene bead. FMOC is used as a protecting group on the N-terminus. Salting Out (Purification) - Changes soluble protein to solid precipitate. Protein precipitates when the charges on the protein match the charges in the solution. Size-Exclusion Chromatography - Separates sample based on size with smaller molecules eluting later. Ion-Exchange...

What amino acids have nonpolar, aliphatic R groups? - Glycine, Alanine, Proline, Valine, Leucine, Isoleucine, Methionine What amino acids have polar, uncharged R groups? - Serine, Threonine, Cysteine, Asparagine, and Glutamine What amino acids have aromatic R groups? - Phenylalanine, Tyrosine, and Tryptophan What amino acids have negatively charged R groups? - Aspartate and Glutamate What amino acids have positively charged R groups? - Lysine, Arginine, and Histidine What is isoel...

what residues are connected through the α helices hydrogen bonds? the hydrogen bonds occur between the H atom of the electronegative N of a peptide linkage and the electronegative carbonyl O atom of the fourth amino acid of the amino-terminal side of that peptide bond how many amino acids are present in a turn of the a helix? 3.6 describe the α helical structure. rigid and rodlike

(T/F) A biochemical reaction, without a catalyst or thermodynamic coupling, takes 50 years to reach a state of equilibrium. Without more information, we cannot make a determination on either the value of the Keq constant or the positive or negative value of the ΔG of the reaction. Correct Answer-False (T/F) Due to its small size, the amino acid glycine can be found in tight turns in a protein structure. Correct Answer-True (T/F) The ΔG of a reaction is defined as the energy required to b...