Advanced Biochemistry: Molecular Genetics and Cellular Processes

Homeotic genes control the pattern of body system formations during embryonic development, making them a likely candidate for conditions that affect multiple systems as seen in Klein-Waardenburg Syndrome.

Enhancers are specific DNA sequences that help regulate gene expression by interacting with transcription factors to enhance transcription at a specific promoter site. They do not directly transcribe genetic material, inhibit RNA polymerase, or exist exclusively in prokaryotic cells.

Acetylation of histones generally leads to increased gene expression by promoting transcriptional activation. This modification modifies the chromatin structure to a more open form, making it easier for transcription factors to access the DNA and initiate gene transcription.

The key feature of the lab technique described is the use of dideoxynucleotides to terminate DNA strands, which is characteristic of DNA sequencing. Polymerase Chain Reaction (PCR) involves amplifying DNA sequences through heating and cooling cycles, Western Blotting is a technique used to detect specific proteins, and Flow Cytometry is used for analyzing and sorting cells based on various parameters.

Gel electrophoresis is a technique used to separate molecules based on their size and charge. DNA segments are treated with restriction enzymes, pipetted into a gel, subjected to an electric field, and visualized under UV light for analysis.

When determining the relationship between 'Possible Parent' and 'Possible child', DNA Fingerprinting is the most accurate method as it compares specific genetic markers through amplification of STRs using PCR.

The correct answer explains the process of collagen synthesis starting from protein translation in the rough endoplasmic reticulum through various posttranslational modifications to form collagen fibrils. The incorrect answers provide inaccurate information about the synthesis of collagen in different cell organelles, diverting from the actual pathway described in the correct answer.

Granulation tissue primarily consists of Type 3 collagen, which is also found in various other tissues such as blood vessels, uterus, fetal tissue, and skin.

Collagen Type 1 is primarily found in the cornea, tendons, and bones, providing strength and structure. On the other hand, Collagen Type 2 is mainly present in the vitreous body, cartilage, and nucleus pulposus, contributing to flexibility and cushioning.

The correct test to determine if a couple is at risk of having a child with 'Constant Infections and Pancreas problems' is PCR and sequencing to identify carriers of the CFTR gene mutation. Blood type testing, X-ray imaging, and urinalysis are not relevant tests for this specific condition.

The first tRNA that carries METHIONINE enters the P site of the ribosome, this is an exception as in other cases tRNA enters the A site before moving to the P site.

The initiation complex in prokaryotes consists of the 30S subunit, an aminoacyl-tRNA bound to N-formylmethionine, and initiation factors. The incorrect answers provided do not reflect the correct components of the initiation complex.

Macrolides, such as erythromycin, work by binding to the 23S RNA of the 50S subunit in the bacterial ribosome, thus preventing the formation of peptide bonds. This mechanism disrupts protein synthesis in bacteria. The incorrect answers provided describe different mechanisms that do not accurately reflect how macrolides function.

The correct procedure to check for CMV in a donor's blood involves using the PCR method.

The 3' to 5' exonuclease activity of DNA polymerase δ is crucial in proofreading during DNA replication to ensure accurate base incorporation, thereby affecting the mutation rate. The incorrect answers do not directly relate to proofreading during DNA replication or mutation rate in humans.

All other choices have DOUBLE-STRANDED DNA composition which should obey the Chargaff's rule's (%A = %T, %C = %G), so we are left with SINGLE-Stranded agents like Picornavirus and Parvovirus. The best choice would be Parvovirus because it is Single-stranded but DNA virus, while Picornavirus is a Single-Stranded RNA virus (Nucleic acid sample would contain Uracil instead of thymine).

Fluroquinolones specifically target Topoisomerase II (DNA gyrase) in prokaryotic cells, inhibiting its function and ultimately disrupting bacterial DNA replication.

Telomerase is the enzyme that best fits the description provided. It plays a key role in maintaining the length of telomeres in rapidly dividing cells. Conditions like aging, immortal cancer cells, and certain diseases like Dyskeratosis congenital, Progeria, and Congenital aplastic anemia are often associated with telomerase dysfunction.

In DNA repair, DNA Ligases are responsible for sealing the phosphodiester bonds in DNA strands that have been damaged. DNA Polymerases are mainly involved in DNA synthesis, while RNA Polymerases transcribe RNA from DNA. Helicases unwind the DNA double helix during processes like replication and repair, but they do not directly catalyze the formation of phosphodiester bonds.

The mutation results in decreased enzyme activity because phosphorylation is a key regulatory mechanism in enzyme function. By preventing phosphorylation, the enzyme's activity is decreased.

The correct way to find mRNA in this case is to identify the 5>3 direction (coding strand) and substitute uracil for thymidines. The mRNA sequence will be the same as the coding strand, except for the substitution of uracil for thymidines.

Transcription of genes by polymerase I occurs in the nucleolus, while polyadenylation of pre-mRNA by poly A polymerase happens in the nucleoplasm, which is a part of the nucleus outside the nucleolus.

Wobble codons often differ only in the third base. UAA would not be the correct answer because it is a STOP codon.

I-cell disease is characterized by the elevation of lysosomal enzymes in the serum due to a defect in Golgi-associated phosphotransferase leading to impaired post-translational modification and transportation through the Golgi apparatus.

When a particular protein is not being secreted properly and instead accumulates in the cytoplasm, it suggests a mutation in the part of the gene that codes for the N-terminal amino acid signal sequence. This signal sequence is crucial for targeting the nascent protein to the endoplasmic reticulum (ER) for proper translocation and secretion. Mutations in other parts of the gene, such as the C-terminal amino acid signal sequence, intron regions, or the promoter region, would not directly impact the translocation of the protein to the ER.

Collagen is rich in glycine, but glycine is not specific enough to identify collagen. Vitamin C is important for collagen synthesis, but measuring its levels does not directly indicate collagen richness. Elastin is a different protein and not relevant for identifying collagen richness in tissue.

Menkes disease is a rare X-linked recessive disorder that causes impaired copper absorption, leading to decreased lysyl oxidase activity and poorly cross-linked connective tissue. This results in symptoms such as fragile bones and blood vessels. Cystic fibrosis affects the lungs and digestive system, hemophilia impairs blood clotting, and Marfan syndrome affects connective tissue but they do not involve functional copper deficiency or decreased lysyl oxidase activity.

A splice-site mutation is a specific type of mutation that can have significant effects on gene expression by altering the splicing of introns and exons in mRNA. This can lead to the production of abnormal proteins or the loss of essential protein function, contributing to various genetic disorders and diseases.