siRNAs are used to:decrease gene expressionincrease gene expressionstop gene expression

The sirtuins are a class of enzymes that regulate various metabolic processes by removing post-translational modifications from enzymes.  SIRT4 is an autosomally encoded sirtuin protein that colocalizes with the pyruvate dehydrogenase complex.  It deacylates lysine (Lys) residues on certain metabolic proteins by removing methylglutaryl and hydroxymethylglutaryl units.  Methylglutaryl-CoA and hydroxymethylglutaryl-CoA are intermediates in leucine (Leu) catabolism, and scientists hypothesized that SIRT4 regulates this pathway.  To test their hypothesis, livers from wild-type (WT) and SIRT4 knockout (KO) mice were treated with α-keto acid derivatives of several amino acids, including the derivative produced from leucine transamination, α-ketoisocaproate (αKIC).  Figures 1 and 2 show the rate of oxidation of α-keto acids and oxygen consumption in both WT and KO livers, respectively.Figure 1  Box plot showing the rate of oxidation of α-ketoisocaproate (αKIC), α-ketoglutarate (αKG), and pyruvate in SIRT4 knockout livers (Note:  Asterisk indicates p < 0.05 relative to WT level.)Figure 2  Oxygen consumption in WT and KO livers in the presence and absence of succinate and reduced cytochrome C (Cyt-C) (Note:  Error bars represent the standard error of the mean (SEM).)Because leucine is known to regulate insulin secretion, scientists injected WT and KO mice with leucine and measured plasma insulin levels over time.  They then injected mice with insulin and monitored blood glucose levels (Figure 3).Figure 3  (A) Plasma insulin levels after injection with leucine and (B) blood glucose levels after injection with insulin in both WT and KO miceAdapted from Anderson KA, Huynh FK, Fisher-Wellman K, et al. SIRT4 Is a Lysine Deacylase That Controls Leucine Metabolism and Insulin Secretion. Cell Metab. 2017;25(4):838-855.e15. Question 29In the absence of SIRT4, the electrochemical potential across the inner mitochondrial membrane:A.is increased relative to mitochondria in the presence of SIRT4.B.is decreased relative to mitochondria in the presence of SIRT4.C.is not changed relative to mitochondria in the presence of SIRT4.D.is increased relative to mitochondria with SIRT4 only when cytochrome C is added.

While microRNAs (miRNAs) are encoded by the genome, short interfering RNAs (siRNAs) are added to cells by researchers. However, both miRNAs and siRNAs work by a similar mechanism. Based on this, which of the following do you expect researchers can learn by the use of siRNAs?Group of answer choicesThe location of any histone modifications.Patterns of alternative gene splicing.Quantitative mRNA expressionNull phenotypes of individual genes.The intracellular location of specific proteins.

Which of the following does not control gene expression?

What is "gene expression"?1 pointprocess by which DNA makes a copy of itself during cell division.the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteinsprocesses that convert chemical energy from oxygen molecules or nutrients into adenosine triphosphate (ATP),the process by which the instructions in our DNA are converted into a functional product, such as a protein.RNA is synthesized on a DNA template in a process called:1 pointmethylationacetlyationtranscriptiontranslationThe enzyme that builds RNA from a DNA template1 pointDNA polymerasRNA polymeraseLigaseRNA primaseGyraseGiven the following DNA strand, which of the following is its complementary mRNA? G G A C T G A T T1 pointC C T G A C T A AC C U G A C U A AG G A C T G A T TT T A G T C A G GSynthesis of mRNA is1 pointin the 5' to 3' direction with new nucleotides being added to the 5' end of the mRNA molecule.in the 3' to 5' direction with new nucleotides being added to the 5' end of the mRNA molecule.in the 5' to 3' direction with new nucleotides being added to the 3' end of the mRNA molecule.in the 3' to 5' direction with new nucleotides being added to the 3' end of the mRNA molecule.able to proceed either from the 5' to 3' or 3' to 5' direction.Transcription begins when the enzyme binds to the1 pointterminator on DNAinitiator on DNApromoter on DNApromoter on RNAA "stop" signal at the end of a gene that causes the completed mRNA to drop off the gene.1 pointterminator on DNAinitiator on DNApromoter on DNAterminator on RNAThe end of a strand of nucleic acid that has a hydroxyl (OH) group on the number 3 carbon of the deoxyribose or ribose.1 point35'A molecule synthesized by complementary base pairing of ribonucleotides with deoxyribonucleotides to match a portion of one strand of DNA coding for a polypeptide or protein.1 pointRNADNAAmino AcidProteinPut the phases in order:3 points1st 2nd 3rdelongation initiation termination elongation initiation termination The DNA strand that is read as the template for making  RNA1 pointsenseantisenseThe following questions reference this diagram:The phase of transcription being illustrated1 pointinitiationelongationterminationThe promoter sequence would be on the ______ side of the diagram1 pointrightleftThe terminator sequence would be on the ______ side of the diagram1 pointrightleftStructure 11 pointHelicaseRNA polymeraseDNA polymeraseRibosomeStructure 21 pointDNA sense strandDNA antisense strandRNA sense strandRNA antisense strandStructure 31 pointRNA nucleotidesDNA nuclotidesAmino acidsStructure 41 pointRNADNAPolypeptideStructure 51 pointDNA sense strandDNA antisense strandRNA sense strandRNA antisense strand

In animal cells, the endogenously produced miRNAs silence gene expression b