Biochemistry C 785 Readiness Check II 2020 – Western Governors University | Biochemistry C785 Readiness Check {A Grade}

Biochemistry C 785 Readiness Check II 2020 – Western Governors University | Biochemistry C785 Readiness Check {A Grade}. Choose the correct coding strand (non-template) from this template (non-coding) DNA: 5' ACG GTA 3' (1/1 Points) 5' UAC CGU 3' 3' UAC CGU 5' 3' TAC CGT 5' 5' TAC CGT 3' Correct! First, note that we are asked for a template/non-coding strand of DNA. DNA uses the base T where RNA uses the base U. Therefore, we can eliminate the two answers containing U because they must be RNA and we want DNA. Then, recall that any strands of nucleic acid that bind to each other (base pairing; A-T/U or C-G) must be each be running in opposite directions (antiparallel; a strand running 5'--3 is bound to a strand running 3'--5'). If any two strands of nucleic acid (for example 2 strands of DNA in a double helix) are complementary (A-T/U or C-G), the two strands must run IN OPPOSITE directions, 5'---3' and 3'---5'. 2 If one strand of chromosome 2 has a DNA sequence that consists of this: 5’ AAG CGG TAC GTA 3’, what will be the composition of the complementary DNA strand? (Select all that apply) (1/1 Points) 5' TTC GCC ATG CAT 3' 3' TTC GCC ATG CAT 5' Correct! All complementary base pairing must be antiparallel. The strand that is complementary to 5’ AAG CGG TAC GTA 3’ is 3' TTC GCC ATG CAT 5'. If we simply 'flip' the sequence, we get 5' TAC GTA CCG CTT 3'. Thus, both of these are the correct answers. 3' TTC GCC ATG CAT 5' 3' TTC GCC ATG CAT 5' 5’ AAG CGG TAC GTA 3’ 3' AAG CGG TAC GTA 5' is similar to the original sequence (5’ AAG CGG TAC GTA 3’), but its 5' and 3' ends are swapped. 5' TAC GTA CCG CTT 3' Correct! All complementary base pairing must be antiparallel. The strand that is complementary to 5’ AAG CGG TAC GTA 3’ is 3' TTC GCC ATG CAT 5'. If we simply 'flip' the sequence, we get 5' TAC GTA CCG CTT 3'. Thus, both of these are the correct answers. 3' TTC GCC ATG CAT 5' 3' TTC GCC ATG CAT 5' 5’ AAG CGG TAC GTA 3’ 3' AAG CGG TAC GTA 5' is similar to the original sequence (5’ AAG CGG TAC GTA 3’), but its 5' and 3' ends are swapped. 3' AAG CGG TAC GTA 5' 5’ ATG TAC GGC GAA 3' 3 The following sequence is the coding strand of the collagen gene: 5’ ATG GCG TTC GAA 3’ What is the sequence of the corresponding mRNA? (1/1 Points) 3' ATG GCG TTC GAA 5' 5' AUG GCG UUC CUU 3' 5' AUG GCG UUC GAA 3' Correct! The coding strand and the mRNA both go in the same direction, but do not both contain Ts. 5' UTG GCG TTC GUU 3' 4 Which ingredients/molecules are required to set up a polymerase chain reaction? Select all that apply. (1/1 Points) Amino Acids RNA nucleotides DNA polymerase Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA. DNA nucleotides Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA. Template DNA Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA. DNA Primers Correct! In PCR, a DNA sample is separated into single strands and incubated with DNA polymerase, deoxynucleotides (dNTPs), and two short DNA primers whose sequences flank the DNA segment of interest and thus define the region to be amplified. Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA. Ribosomes RNA Primers 5 Which of the following steps in PCR occurs first? (1/1 Points) Elongation Annealing Cycling Denaturation Correct! Denaturation separated the DNA strands. The DNA strands must be separated to expose the bases to which the primers will bind. 6 Which statement accurately describes how a frameshift mutation affects a gene? (0/1 Points) It will change a single nucleotide in a mutant gene compared to the normal gene. Examples are missense, nonsense, and silent mutations. It will change the number of nucleotides in a mutant gene compared to the normal gene. Examples are missense, nonsense, and silent mutations. It will change a single nucleotide in a mutant gene compared to the normal gene. Examples are insertion and deletion mutations Incorrect. - If you chose ‘change a single nucleotide in a mutant gene compared to the normal gene. Examples are missense, nonsense, and silent mutations”, this is incorrect. This is the correct definition of Point Mutations. Background: Errors that change the number of nucleotides in a gene (insertion/deletion) are said to ‘shift’ the ‘reading frame’ from the correct groups of three basses to new groups. To visualize what a frameshift is, imagine you are given a string of letters and told to start at the beginning and read every group of three letters: CATDOGRATPIGAPE. You would get "cat dog rat pig ape". But if we add an extra letter, say CATDFOGRATPIGAPE, following our "read every group of three" rule, we would get "cat dfo gra tpi gap e". Shifting our 'reading frame' by adding one more letter completely changes what we read. This is similar to what happens with a frameshift mutation. It will change the number of nucleotides in a mutant gene compared to the normal gene. Examples are insertion and deletion mutations. 7 If the coding DNA sequence of a normal gene is 5' GTC GCA TGG TGA 3', what kind of mutation would create the mutant gene sequence 5' GTC GAC ATG GTG A 3'? (1/1 Points) Silent mutation Nonsense mutation Insertion mutation Correct! Background. An insertion mutation adds nucleotides to a gene and is a type of frameshift mutation, which changes the way the mRNA codons are read, changing the amino acid sequence. See Figure 1-19 in the Module 1 text for more information. Deletion mutation 8 This learning objective is now tested in a different WGU course than Biochemistry. Please select True. True Incorrect. Incomplete dominance produces a blended phenotype. False 9 This learning objective is now tested in a different WGU course than Biochemistry. Please select True. True Incorrect. The first generation contains unaffected parents having affected offspring, also known as carriers. Therefore, it must be recessive. Since only males are affected, it is X-linked recessive. False 10 This learning objective is now tested in a different WGU course than Biochemistry. Please select True. True Incorrect. Genetic changes result from alterations of the DNA sequence itself - such as mutations. False 11 The LEP gene codes for an anorexigenic hormone. Interestingly, breastfeeding has been shown to alter methylation of the promoter of this gene, leading to increased LEP expression. What is likely happening in response to breastfeeding? (0/1 Points) Breastfeeding increases the methylation of the promoter of the LEP gene, decreasing the spacing between nucleosomes. Breastfeeding decreases the methylation of the promoter of the LEP gene, increasing the spacing between nucleosomes. Breastfeeding decreases the methylation of the promoter of the LEP gene, decreasing the spacing between nucleosomes. Breastfeeding increases the methylation of the promoter of the LEP gene, and the tight packing of the DNA alters binding of RNA polymerase. Incorrect. When histones wrap up DNA, transcription will be repressed. 12 After skiing during a winter vacation and getting a mild facial tan, a patient had an untimely herpes flare-up on his upper lip. Herpes Simplex Type I, is the most common cause of cold sores. HSV-1 is a DNA retrovirus that embeds itself into the host genome, as long as the HSV-1 genes are expressed the symptoms will persist. What caused the herpes flare-up? (1/1 Points) the HSV-1 genes became open and available as the result of repairing UV damage, decreasing HSV-1 expression the HSV-1 genes became closed and hidden as the result of repairing UV damage, increasing HSV-1 expression the HSV-1 genes became closed and hidden as the result of repairing UV damage, decreasing HSV-1 expression the HSV-1 genes became open and available as the result of repairing UV damage, increasing HSV-1 expression 13 A patient with xeroderma pigmentosum is prone to developing multiple skin cancers starting in childhood. This occurs because of a mutation in a gene that codes for enzymes that help repair DNA damage through the nucleotide excision repair (NER) pathways. How does NER differ from other repair mechanisms? In NER: (0/1 Points) Only one nucleotide is removed and DNA polymerase replaces the one abnormality Incorrect. If you chose, only one nucleotide is removed and DNA polymerase replaces the one abnormality, this is incorrect. This is the description of base excision repair, which is a repair mechanism utilized to repair single nucleotides. See Figure 1-21 in module 1. The error in one strand of DNA is removed as well as several nucleotides on either side of the error. The gap that was removed is filled in by DNA polymerase The entire homologous chromosome is used to repair the double stranded DNA error The affected DNA strand and its complementary strand is discarded and a new double stranded DNA is created 14 Several components of cigarette smoke, including benzopyrene, insert themselves (intercalate) into the DNA and lead to several types of mutations such as frameshift mutations, including both insertions and deletion. Which of the following repair pathways would be used to repair this type of damage? (1/1 Points) Nucleotide Excision Repair Correct! Nucleotide excision repair is used to repair deletions, insertions, and helixdistorting lesions, such as thymine dimers. To learn more about this, please visit Lesson 1: DNA and RNA; Chapter - Inheritance of Genes; Subchapter - DNA Damage and Repair; Section - Excision Repair Corrects The Most Frequent DNA Lesions. Base excision repair Homologous Recombination Mismatch Repair 15 What bond is indicated by the arrow in the diagram? (1/1 Points) Ionic bond Peptide bond If you answered "peptide bond: you are correct!. A peptide bond is the bond formed between a C=O and a N-H of two different amino acids. It will be represented by a solid line. The arrow points to this type of bond. Hydrogen bond Metallic bond 16 Interaction between the two amino acids shown below can help stabilize the structure of a protein. What kind of interaction is this? (1/1 Points) Hydrogen bond Hydrophobic interaction If you selected Hydrophobic, you are correct. Hydrophobic interactions are made by amino acids that have carbon and hydrogen atoms bonded to each other on the outermost portions of their R groups. Ionic bond Disulfide bond 17 Which pair of amino acids below can form an ionic bond? (1/1 Points) Option 1 Option 2 Option 3 If you picked option 3, you are correct! Amino acids with side chains that are oppositely charged can form ionic bonds. The charges on charged amino acids are visibly displayed on the R group of the individual amino acids. Option 4 18 Which of the following forces can lead to aggregation as a result of protein misfolding? (1/1 Points) 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). hydrogen bonds disulfide bonds ionic bonds 19 Which of the following statements about protein structure and stability is true? (1/1 Points) Denatured proteins retain their tertiary structure Ionic bonds between the side chains of the charged amino acids stabilize the protein structure Correct! The true statement is "Ionic bonds between the side chains of the charged amino acids stabilize the protein structure." Ionic bonds help stabilize both the tertiary structure of a protein chain and the quaternary structure of a protein with multiple subunits. Please see "R Group Contributions to Protein Structure and Stability" in Module 2, Lesson 1 under "Levels of Protein Structure" for more information. Denaturation is the loss of primary, secondary, and tertiary structure Protein structure is not stabilized by the hydrophobic effect 20 Primary structure consists of the order of ______ in a protein. These are held together with ______ bonds that are formed by a ______ reaction. (0/1 Points) Nucleotides, phosphodiester, dehydration Amino acids, peptide, hydrolysis Amino acids, peptide, dehydration Nucleotides, peptide, dehydration Incorrect. Protein primary structure is defined by the order of amino acids that make up the protein. The amino acids are linked together by peptide bonds, which are formed via dehydration reactions. If you chose "Nucleotides, peptide, dehydration:" Nucleotides make up DNA and RNA, not proteins. 21 What type of reaction breaks peptide bonds apart? (0/1 Points) Methylation Reaction Oxidation/Reduction Reaction Incorrect. Peptide bonds are formed by dehydration reactions (named for the loss of water that occurs) and broken via hydrolysis (named for the addition of water: "hydro-" meaning water, and "-lysis" meaning cutting, i.e. water cuts the peptide bond). If you chose "Oxidation/Reduction Reaction:" This reaction transfers electrons from one molecule to another. Hydrolysis Reaction.