Signal Transduction Pathway Involving G-Protein Coupled Receptors

<p>Acting as a water-hydrated gel to resist compression (D)</p> Signup and view all the answers

<p>Erythrocytes, polymorphonuclear leukocytes, and brain cells (D)</p> Signup and view all the answers

<p>Acting as a fibrous protein to provide tensile strength and recoil (A)</p> Signup and view all the answers

<p>To cleave phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-triphosphate (IP3) and diacylglycerol (DAG) (C)</p> Signup and view all the answers

<p>It is essential for the synthesis of purine nucleotides (C)</p> Signup and view all the answers

<p>It inhibits them at a delayed time (A)</p> Signup and view all the answers

<p>Framework for fibrous proteins (D)</p> Signup and view all the answers

<p>It helps activate protein kinase C (PKC) along with calcium and phosphatidylserine (A)</p> Signup and view all the answers

<p>It is an early participant in the synthesis of purine nucleotides (C)</p> Signup and view all the answers

<p>It releases calcium ions from the endoplasmic reticulum into the cytosol (A)</p> Signup and view all the answers

<p>To convert ribonucleosides and deoxyribonucleosides into their respective nucleotides (D)</p> Signup and view all the answers

<p>Uridine monophosphate synthetase (UMPS) (B)</p> Signup and view all the answers

<p>It activates phospholipase C (PLC) (A)</p> Signup and view all the answers

<p>It translocates PKC from the cytosol to the plasma membrane (C)</p> Signup and view all the answers

<p>The former is involved in pyrimidine synthesis, while the latter is involved in urea synthesis (D)</p> Signup and view all the answers

<p>To generate fibers that attach sister chromatids to spindle fibers (C)</p> Signup and view all the answers

<p>Chromatin condenses, mitotic spindle fibers form, and nucleolus disappears (D)</p> Signup and view all the answers

<p>To generate fibers that separate chromosomes during mitosis and meiosis (D)</p> Signup and view all the answers

<p>Chromatin condenses and mitotic spindle fibers form (C)</p> Signup and view all the answers

<p>Interphase (D)</p> Signup and view all the answers

<p>To form asters (B)</p> Signup and view all the answers

<p>Providing selective permeability and maintaining cell surface protein distribution (C)</p> Signup and view all the answers

<p>Claudin (B)</p> Signup and view all the answers

<p>Allowing the passage of small water-soluble molecules and signaling between two cells (B)</p> Signup and view all the answers

<p>Cell growth and preparation for mitosis (D)</p> Signup and view all the answers

<p>Chromatin (C)</p> Signup and view all the answers

<p>G0 phase (D)</p> Signup and view all the answers

<p>147 bp (D)</p> Signup and view all the answers

<p>To bind to the nucleosomal core particle around the DNA entry and exit sites (B)</p> Signup and view all the answers

<p>30-nm chromatin fiber (B)</p> Signup and view all the answers

<p>Mitosis (D)</p> Signup and view all the answers

<p>Compressing and folding (B)</p> Signup and view all the answers

<p>To allow for gene expression (B)</p> Signup and view all the answers

<p>To recognize the promoter sequence and unwind the double helix of DNA (B)</p> Signup and view all the answers

<p>To form a complex with RNA polymerase and recognize the promoter sequence (B)</p> Signup and view all the answers

<p>TTGACA (A)</p> Signup and view all the answers

<p>5 (C)</p> Signup and view all the answers

<p>50 nt/sec (C)</p> Signup and view all the answers

<p>5’ to 3’ (B)</p> Signup and view all the answers

<p>DNA polymerase I (C)</p> Signup and view all the answers

<p>To prevent degradation by exonucleases (A)</p> Signup and view all the answers

<p>Okazaki fragments (D)</p> Signup and view all the answers

<p>To correct base pairing errors (B)</p> Signup and view all the answers

<p>1-5% (C)</p> Signup and view all the answers

<p>Splicing (B)</p> Signup and view all the answers

<p>To synthesize RNA primers (D)</p> Signup and view all the answers

<p>3’ to 5’ (A)</p> Signup and view all the answers

<p>Heteronuclear RNA (hnRNA) (C)</p> Signup and view all the answers

<p>Both nucleus and cytoplasm (C)</p> Signup and view all the answers

<p>Non-coding strand (D)</p> Signup and view all the answers

<p>Irreversible and destructive (C)</p> Signup and view all the answers

<p>They facilitate the dimerization of initiator caspases (C)</p> Signup and view all the answers

<p>The executioner caspases dimer undergoes an activating conformational change (A)</p> Signup and view all the answers

<p>They are inactive monomers (D)</p> Signup and view all the answers

<p>C-terminal region (D)</p> Signup and view all the answers

<p>The initiator caspase is activated (C)</p> Signup and view all the answers

<p>The 𝜎 subunit of RNAP increases specificity for promoters, allowing transcription to initiate at correct sites, while reducing affinity for nonspecific DNA.</p> Signup and view all the answers

<p>The RNAP holoenzyme detects the -35 sequence, forms a closed complex, and then moves down to the DNA strand, recognizes and binds to the Pribnow box, and unwinds the dsDNA helix to create an open complex (transcription bubble) by performing helicase activity.</p> Signup and view all the answers

<p>The RNA polymerase retains all its phosphate groups during the synthesis of the first ribonucleoside triphosphate, indicating that the RNA synthesis does not require priming.</p> Signup and view all the answers

<p>The alpha phosphate group, the one closest to the ribose sugar, is retained during the synthesis of subsequent ribonucleoside triphosphates, while the other two phosphate groups are released as orthophosphate.</p> Signup and view all the answers

<p>The RNAP holoenzyme performs helicase activity to unwind the DNA and break the hydrogen bonds between the T:A base pairs, requiring less energy to melt down this region.</p> Signup and view all the answers

<p>The -35 sequence is recognized by the RNAP holoenzyme, allowing it to bind to the promoter and initiate transcription.</p> Signup and view all the answers

<p>Alternative splicing leads to different mRNA transcripts, which can be translated to different proteins with distinct structures and functions, resulting in increased phenotypic diversity.</p> Signup and view all the answers

<p>Epigenetic mechanisms, such as histone modification and DNA methylation, regulate gene expression by altering chromatin structure and accessibility to transcription factors, without changing the underlying DNA sequence.</p> Signup and view all the answers

<p>The different levels of protein structure are crucial for determining protein function, as they influence the protein's overall shape, binding properties, and enzymatic activity.</p> Signup and view all the answers

<p>During translation, amino acids are polymerized into a polypeptide chain through the interaction of ribosomes, messenger RNA, and transfer RNA, with the RNA sequence serving as a template for the growing polypeptide chain.</p> Signup and view all the answers

<p>Genomic imprinting is a mechanism that regulates gene expression by selectively silencing one of the two parental alleles in a diploid cell, resulting in parental-origin-specific gene expression.</p> Signup and view all the answers

<p>Epigenetic mechanisms, such as histone modification and DNA methylation, regulate gene expression by altering chromatin structure and accessibility, whereas cis-elements and transcription factors regulate gene expression by binding directly to specific DNA sequences.</p> Signup and view all the answers

<p>Post-translational modification of proteins involves the addition of specific functional/chemical groups to amino acid side chains, altering protein conformation and properties. Types of modifications include phosphorylation, acetylation, lipid modification, and glycosylation. These modifications are generally reversible, affecting protein stability, localization, interacting partners, and activity. They play essential roles in regulating the functions of many important eukaryotic proteins.</p> Signup and view all the answers

<p>A single base substitutional change from A to T can result in the substitution of Val for Glu. This occurs because the change in the codon sequence alters the amino acid specified during translation.</p> Signup and view all the answers

<p>Silent variants do not change the amino acid sequence, missense variants change the amino acid, and nonsense variants result in a premature stop codon. These variants can have different effects on protein function, ranging from no effect to complete loss of function.</p> Signup and view all the answers

<p>Ubiquitination is a post-translational modification that marks proteins for degradation by attaching ubiquitin molecules. This process is essential for regulating protein turnover and maintaining protein homeostasis.</p> Signup and view all the answers

<p>Post-translational modifications are generally reversible, with one enzyme adding the modifying group and another enzyme removing it. For example, phosphorylation by protein kinases can be reversed by phosphatases.</p> Signup and view all the answers

<p>Post-translational modifications play a crucial role in regulating protein function, influencing protein stability, localization, and activity. They are essential for various cellular processes, including cellular signaling, protein-protein interactions, and protein degradation.</p> Signup and view all the answers

<p>dsDNA has less absorbance at 260nm than ssDNA due to the stacking interactions between the bases, known as the hypochromic effect. When dsDNA denatures, the absorbance increases.</p> Signup and view all the answers

<p>The nucleoid is a region in the cytoplasm of prokaryotes that houses the genetic material, consisting of mostly DNA, together with RNAs and proteins, including mRNAs, transcription factor proteins, and ribosomes. Nucleoid-associated proteins (NAPs) maintain the nucleoid structure.</p> Signup and view all the answers

<p>A nick in a supercoiled plasmid allows it to gradually unwind, releasing the torsional energy until it reaches its final, circular, relaxed state.</p> Signup and view all the answers

<p>Topoisomerases catalyze the interconversion between relaxed and supercoiled forms of DNA, allowing for the release of torsional energy and the maintenance of DNA structure.</p> Signup and view all the answers

<p>The bacterial chromosome is a single or multiple, circular or linear chromosome found in the nucleoid region of the cytoplasm, whereas the eukaryotic nucleus is a membrane-bound organelle that houses the genetic material. The bacterial chromosome is not surrounded by a nuclear membrane, unlike eukaryotic cells.</p> Signup and view all the answers

<p>The hyperchromic effect is the increasing ability of DNA to absorb light as it denatures, which is used to measure the denaturation of dsDNA.</p> Signup and view all the answers

<p>To harbor promoters for transcription and the origin for H-strand DNA replication</p> Signup and view all the answers

<p>The formation of a triple-stranded displacement-loop structure and the production of a short H-strand replication product called 7S DNA</p> Signup and view all the answers

<p>To initiate primer synthesis</p> Signup and view all the answers

<p>The origin of replication for the H-strand is located within the noncoding region, while the origin of replication for the L-strand is located outside the noncoding region, within a tRNA cluster</p> Signup and view all the answers

<p>Each stretch must start with its own RNA primer</p> Signup and view all the answers

<p>13</p> Signup and view all the answers