WGU785 BIOCHEMISTRY FINAL EXAM 100 QUESTIONS WITH VERIFIED CORRECT ANSWERS/A+ GRADE VERSION

Hemophilia Pedigree - Father has hemophilia, mother does not. What is the outcome for their kids? Correct answer- His daughters would be carriers. This is x-link recessive. Autosomal: Dominant: Correct answer- Autosomal: males and females equally affected. Dominant: non-carrier parents polymerase chain reaction (PCR) Correct answer- The process of copying DNA in the lab. Uses Template DNA, Nucleotides (dNTPS), DNA Polymerase, and DNA primers. 3 Steps of PCR Correct answer- 1. Denaturation: DNA is heated to 95C to separate it. 2. Annealing: reaction is cooled to 50C; primers stick to the DNA you want to copy and add DNA polymerase. 3. Elongation: reaction heated to 70C and DNA polymerase, adding nucleotides building a new DNA strand. Base Excision Repair (BER) Correct answer- How you repair a mutation. BER is used to repair damage to a base caused by harmful molecules. You remove the base that is damaged and replace it. *BER removes a single nucleotide* DNA glycolsylase - sees damaged DNA and removes it. DNA polymerase-puts the right one back in while DNA ligase seals it. Mismatch repair (MMR) occurs during: Correct answer- replication. DNA polymerase proofreads but sometimes a mismatch pair gets through. MMR removes a large section of the nucleotides from the new DNA and DNA polymerase tries again. (Ex: C-T instead of C-A) Mismatch Repair corrects what kind of DNA damage? Correct answer- When a base is mismatched due to errors in replication. Such as G-T instead of G-C. DNA polymerase comes by and fixes it. What happens when DNA polymerase binds to DNA to make RNA? Correct answer- TRANSCRIPTION! DNA polymerase takes the individual nucleotides and matches them to the parental sequences to ensure a correct pair. It must bind with RNA primer to work. WGU785 BIOCHEMISTRY FINAL EXAM 100 QUESTIONS WITH VERIFIED CORRECT ANSWERS/A+ GRADE 2023 VERSION What is needed for DNA replication? Correct answer- DNA polymerase Nonsense Mutation Correct answer- Change in 1 nucleotide produces a STOP codon Stop= nonsense because it is no more. Silent Mutation Correct answer- Change in 1 nucleotide but codes for the same amino acid. Silent= the change doesn't change the name of the protein Missense Mutation Correct answer- Change in 1 nucleotide leads to a code for a different amino acid. Missense = mistake was made. What happends during RNA splicing? Correct answer- During RNA splicing introns are cut out, the remaining exons are joined together. 5'ATG AGT CTC TCT 3' Find the DNA template strand. Correct answer- 3'TAC TCA GAG AGA 5' The DNA template strand is complimentary. So start with the opposite number, then go L-R with the complimentary letter. 5'ATG AGT CTC TCT 3' What is the corresonding mRNA sequence? Correct answer- 5'AUG AGU CUC UCU 3' This sequence is the same as the coding strand except T changes to U because it is RNA. RNA doesn't have T. How would a mutation from CTC to ATC affect the protein sequence? (CTC/ATC - coding strand, AUC - mRNA strand) Correct answer- This will make a missense mutation because it changes the name of the protein. (look at the chart provided.) missense = mistake DNA replication process Correct answer- DNA -Transcription - RNA - Translation - Polypeptide Describe how you would find what ionized Alanine looks like. WGU785 BIOCHEMISTRY FINAL EXAM 100 QUESTIONS WITH VERIFIED CORRECT ANSWERS/A+ GRADE 2023 VERSION Correct answer- This is an amino acid. Look for the "R" group. Alanine is a hydrophobic amino acid that has CH3. It is a weak interaction. An ionized acid will have a + or - charge. Describe what causes the misfolding of protein in Alzheimer's Disease. Correct answer- Protein misfolding is caused by intracellular tangles and extracellular plaques (senile plaques) caused by abnormal protein aggregation. TAU is fibrous material inside cells where the connections are lost. This becomes defective and forms filaments in the neuron. Amyloid-Beta is a large precursor protein in the cell. Excess amyloid-beta creates senile plaques. This starts in the hippocampus and moves up. Describe the process of neurodegenerative protein aggregation. Correct answer- Alzheimer's is the most common neurodegenerative disease. The formation of aggregated amyloid-beta fibers is another characterisitc of Alzheimer's. However, neurodegeneration and memory loss can be detected before amyloid fibers accumulate in the brain. What are the molecules that help denatured proteins with folding? Correct answer- Molecular chaperones are protein helpers. They bind to the newly made polypeptide and enable proper folding. Proper protein folding is vital b/c proteins that do not fold properly can lead to a variety of diseases. Normally, the chaperones that help new proteins fold can also help misfolded proteins refold into the correct structure. Genetic mutations that substitute one amino acid for another can cause incorrect folding. What are the 4 levels of protein structure? Correct answer- 1. Primary-chain of amino acids. PEPTIDE bonds form a polypeptide chain. This is a covalent bond (very strong) and does not denature. 2. Secondary-alpha helix and beta sheet. HYDROGEN bonds that contain the carboxyl group and amino groups. Denatured by salt and pH change. 3. Tertiary-side chain interaction (R group). Changes are seen with high temp, salt, change in pH, and reducing agents. (ex: sickle cell, arthritis, hemophilia) 4. Quarternary-more than 1 polypeptide. Change seen with increased temp. (Ex: Hgb) Hydrogen bonds are formed from Correct answer- 2 polar amino acids. (Contains Oxygen and nitrogen-OH, NH, NH2. On exterior surface)