biochemistry module 2 (part 1) extra questions

Which of the following best describes the nature of protein primary structure? a. Structural elements such as alpha helices and beta pleated sheets b. Amino acids linked together in a specific order by peptide bonds c. Two or more polypeptide chains coming together to form the final functional protein d. The overall three-dimensional shape of a chain of amino acids

Amino acids linked together in a specific order by peptide bonds

As a piece of bacon is heated in a skillet on the stove, you observe that the appearance of the bacon changes. You may even notice that the bacon becomes crispy if left in the skillet. What type of bonds or interactions in proteins are susceptible to temperature changes? Why? a. Hydrophobic interactions. Hydrophobic interactions are oily, when the bacon grease cooks away from the bacon it takes away the hydrophobic interactions. b. Hydrophobic interactions. As the temperature increases, as it does in the skillet, the atoms in the proteins in bacon begin to move more rapidly. This causes the hydrophobic areas of the protein to become exposed. c. Ionic bonds. As the bacon cooks, charged amino acids become neutral causing proteins to aggregate. This aggregation causes the characteristic look of crispy bacon. d. Disulfide bonds. Disulfide bonds are associated with the smell of cooking bacon.

Hydrophobic interactions. As the temperature increases, as it does in the skillet, the atoms in the proteins in bacon begin to move more rapidly. This causes the hydrophobic areas of the protein to become exposed.

Which of the following statements about protein structure and stability is true? a. Denaturation is the loss of primary, secondary, and tertiary structure b. Denatured proteins retain their tertiary structure c. Ionic bonds between the side chains of the charged amino acids stabilize the protein structure d. Protein structure is not stabilized by the hydrophobic effect

Ionic bonds between the side chains of the charged amino acids stabilize the protein structure

Which of the following statements about the secondary structure of proteins is true? You may select more than one answer. a. It involves hydrogen bonding between the backbone atoms b. It includes alpha helices as a common form. c. It includes beta pleated sheets as a common form. d. It involves hydrogen bonding between amino acid side-chains.

It involves hydrogen bonding between the backbone atoms It includes alpha helices as a common form. It includes beta pleated sheets as a common form.

Which of the following are true about a misfolded protein? You may select more than one answer. a. It will lose its normal function. b. It can be degraded by the cell. c. It can be the result of denaturation. d. It can cause protein aggregation. e. It loses its primary structure.

It will lose its normal function. It can be degraded by the cell. It can be the result of denaturation. It can cause protein aggregation.

Aggregation of proteins is the main reason behind many neurodegenerative diseases. Which one of the following mutations will likely cause a neurodegenerative disease? a. Replacing a positively charged amino acid with a negatively charged amino acid b. Replacing a polar amino acid with a non polar amino acid c. Replacing a polar amino acid with another polar amino acid d. Replacing a negatively charged amino acid with a negatively charged amino acid

Replacing a polar amino acid with a non polar amino acid

Which of the following statements about the different levels of protein structure is true? a. Two or more polypeptides each with their own secondary structures come together to form a single larger tertiary structure of a protein b. Peptide bonds between amino acids make up the secondary structure of a protein c. The interactions between the side chains of the amino acids make up the secondary level structure of a protein d. The interactions between the side chains of the amino acids make up the tertiary level structure of a protein

The interactions between the side chains of the amino acids make up the tertiary level structure of a protein.

Which of the following statements is true about the secondary structure of proteins? a. It involves hydrogen bonding between the backbone atoms. b. It includes alpha helices as a common form. c. It includes beta pleated sheets as a common form. d. All of these.

all of these

When Estrogen binds to the binding pocket of the Estrogen Receptor, it is stabilized by hydrogen bonds. Which amino acids listed below could stabilize the interaction with Estrogen in the binding pocket of the Estrogen Receptor? Check all that apply. a. Amino Acid 1 b. Amino Acid 3 c. Amino Acid 10 d. Amino Acid 16

amino acid 16

Primary structure consists of the order of ______ in a protein. These are held together with ______ bonds that are formed by a ______ reaction. a. Nucleotides, phosphodiester, dehydration b. Amino acids, peptide, hydrolysis c. Amino acids, peptide, dehydration d. Nucleotides, peptide, dehydration

amino acids, peptide, dehydration

Primary structure is defined by the order of ______ in a protein. These are held together by ______ bonds that are formed as a result of a ______ reaction. a. Nucleotides, phosphodiester, dehydration b. Amino acids, peptide, hydrolysis c. Amino acids, peptide, dehydration d. Nucleotides, peptide, dehydration

amino acids, peptide, dehydration If you selected Amino acids, peptide, dehydration, you are correct. The ordered sequence of amino acids in a linear chain is what defines the primary level of protein structure. The peptide bond is what joins the amino acid together and the reaction that facilitates the joining is a dehydration reaction.

In order to fulfill their function, proteins must fold in proper, three-dimensional conformations. Which one of the following molecules, available in a cell, is likely to help a protein fold properly? a. Cysteine b. Glycine c. Chaperone d. Polymerase

chaperone

In order to fulfill their function, proteins must fold in proper, three-dimensional conformations. Which one of the following molecules, available in a cell, is likely to help a protein fold properly? a. Cysteine b. Glycine c. Chaperone d. Polymerase

chaperone If you selected chaperone, you are correct. A chaperone is a molecule in the cell that grabs onto a newly made protein and helps it reach its native (fully folded) state.

Which type of bonding or interaction is correctly paired with a chemical or change in environment that will disrupt/break the interaction or bond? a. Peptide bonds: Reducing agents b. Hydrophobic interactions: Change in pH c. Peptide bonds: Change in pH d. Hydrogen bonds/ionic bonds: Change in pH

d. Hydrogen bonds/ionic bonds: Change in pH

A toddler mistakenly swallows a bathroom cleaning solution, containing a strong reducing agent. Which interaction is most likely to be disrupted within a glycoprotein in the lining of the toddlerʼs esophagus? a. Hydrogen Bond b. Disulfide Bond c. Hydrophobic interactions d. Ionic Bonds

disulfide bond

Which of the following interactions can only occur between two cysteine amino acids? a. hydrogen bond b. hydrophobic interaction c. disulfide bond d. ionic bond e. none of these

disulfide bond If you selected disulfide bond, you are correct. Disulfide bonds only occur between two cysteine amino acids.

A diabetic patient is suffering from ketoacidosis. Which interaction(s) could be disrupted within the patientʼs hemoglobin due to this condition. (Click all that apply) a. Hydrogen Bond b. Disulfide Bond c. Hydrophobic Interactions d. Ionic Bonds

hydrogen bond, ionic bonds

What type of reaction breaks peptide bonds apart? a. Condensation Reaction b. Methylation Reaction c. Hydrolysis Reaction d. Oxidation/Reduction Reaction

hydrolysis reaction

Alzheimer disease is caused by aggregation of the Amyloid beta peptide and tangle formation by the tau protein. What kinds of amino acids are likely to drive the formation of these protein aggregates? a. Hydrophobic b. Hydrophilic c. Polar d. Cysteine

hydrophobic

Alzheimer's disease is caused by aggregation of the Amyloid beta peptide and tangle formation by the tau protein. What kinds of amino acids are likely to drive the formation of these protein aggregates? a. Hydrophobic b. Hydrophilic c. Polar d. Cysteine

hydrophobic If you selected hydrophobic, you are correct. Hydrophobic amino acids like to hide from water and in so doing they will cause aggregation (clumping up) of the tau protein.

Which of the following interactions can occur between two non-polar amino acids? a. hydrogen bond b. hydrophobic interaction c. disulfide bond d. ionic bond e. none of these

hydrophobic interaction If you selected hydrophobic interaction, you are correct. Two non-polar amino acids would form a hydrophobic interaction between them.

A patient presents with a fever of 110°F. Which interaction(s) would be disrupted within a neuronal protein if the fever is not resolved quickly. a. Hydrogen Bond b. Disulfide Bond c. Hydrophobic Interactions d. Ionic Bonds

hydrophobic interactions

As a piece of bacon is heated in a skillet on the stove, you observe that the appearance of the bacon changes. You may even notice that the bacon becomes crispy if left in the skillet. What types of bonds or interactions in proteins are susceptible to temperature changes? a. Ionic Bonds b. Hydrogen Bonds c. Hydrophobic interactions d. Disulfide Bonds

hydrophobic interactions

Which of the following forces can lead to aggregation as a result of protein misfolding? a. disulfide bonds b. hydrogen bonds c. ionic bonds d. hydrophobic interactions

hydrophobic interactions

Which of the following forces can lead to aggregation as a result of protein mis-folding? a. disulfide bonds b. hydrogen bonds c. ionic bonds d. hydrophobic interactions

hydrophobic interactions If you selected hydrophobic interactions, you are correct. When proteins misfold, their hydrophobic amino acids at their cores are exposed to the aqueous environment in the cell. To avoid water, the hydrophobic/nonpolar amino acids that have been exposed will interact with other hydrophobic/nonpolar amino acids, causing aggregation (the linking of proteins together in clumps).

Several types of side chain interactions stabilize the tertiary structure of proteins, including which of the following? a. Hydrogen bonds, phosphodiester bonds, peptide bonds, covalent bonds b. Ion pairs, peptide bonds, protein bonds, hydrogen bonds. c. Ionic bonds, hydrophobic interactions, hydrogen bonds, disulfide bonds d. Peptide bonds, hydrogen bonds, ester bonds, covalent bonds

ionic bonds, hydrophobic interactions, hydrogen bonds, disulfide bonds If you selected Ionic bonds, hydrophobic interactions, hydrogen bonds, disulfide bonds, you are correct. Ionic bonds form between two oppositely charged R groups, hydrogen bonds occur between two polar R groups, disulfide bonds form between two cysteine amino acids and hydrophobic interactions occur between two non-polar amino acids.

A mutation in the protein A gene results in a negatively charged amino acid, Glutamate, being replaced with the nonpolar amino acid Leucine. This is an example of a _______ mutation that could potentially interrupt __________. a. nonsense, a hydrogen bond b. missense, a disulfide bond c. nonsense, a hydrophobic interaction d. missense, an ionic bond

missense, an ionic bond

A mutation in the gene coding for protein A results in a negatively charged amino acid, Glu, being replaced with the non-polar amino acid Leu. This is an example of a _______ mutation that could potentially interrupt __________. a. nonsense, a hydrogen bond b. missense, a disulfide bond c. nonsense, a hydrophobic interaction d. missense, an ionic bond

missense, an ionic bond If you selected missense, an ionic bond, you are correct. Missense is the right type of mutation, a change from one amino acid to another. The negatively charged glutamate would form an ionic bond with a positively charged amino acid.

The amino acid valine contains an 'R' group that consists of carbon and hydrogen atoms. Which of the following groups does valine belong to? a. charged b. polar c. non-polar d. aromatic

non-polar If you selected non-polar you are correct. Non-polar/hydrophobic amino acid have R groups that contain carbons (C) and hydrogens (H) on the outside surface of their R groups.

Which of the following interactions can occur between two positively charged amino acids? a. hydrogen bond b. hydrophobic interaction c. disulfide bond d. ionic bond e. none of these

none of these If you selected none of these, you are correct. Two positively charged amino acids would repel each other. Only opposite charged attract.

Which of the following interactions involve a covalent bond? (check all that apply) a. peptide bond b. hydrogen bond c. hydrophobic interaction d. ionic bond e. disulfide bond

peptide bond, disulfide bond

The negatively charged amino acid, Glutamate, is replaced with the negatively charged amino acid Aspartate. Which level of protein structure is most significantly impacted by this change? a. primary structure b. secondary structure c. tertiary structure d. quaternary structure

primary structure

The negatively charged amino acid, Glu, is replaced with the negatively charged amino acid Asp. Which level of protein structure is likely to be impacted by this change? a. primary structure b. secondary structure c. tertiary structure d. quaternary structure

primary structure If you selected primary structure, you are correct. The primary structure of amino acids refers to the sequence of amino acids (the order that they are attached to each other). This level of protein structure doesn't contain a definite shape.