Gene Expression and Central Dogma

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

<p>Changes in the amino acid sequence (D)</p> Signup and view all the answers

<p>Inherited diseases that are caused by enzyme deficiencies (A)</p> Signup and view all the answers

<p>To edit specific genes (C)</p> Signup and view all the answers

<p>Aminoacyl-tRNA synthetase activity (C)</p> Signup and view all the answers

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

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

<p>Through nucleotide-pair substitutions, insertions, or deletions (D)</p> Signup and view all the answers

<p>They cause specific or random changes in DNA (C)</p> Signup and view all the answers

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

<p>Alteration in the grouping of codons (C)</p> Signup and view all the answers

<p>Nucleotide-pair substitutions (D)</p> Signup and view all the answers

<p>By adjusting transcription levels (B)</p> Signup and view all the answers

<p>Inhibits the final product's synthesis (A)</p> Signup and view all the answers

<p>They modify chromatin structure (A)</p> Signup and view all the answers

<p>In a tryptophan-rich environment (C)</p> Signup and view all the answers

<p>Change of one amino acid for another (B)</p> Signup and view all the answers

<p>Substitutions between nucleotide pairs (A)</p> Signup and view all the answers

<p>Catalyzes the formation of peptide bonds (A)</p> Signup and view all the answers

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

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

<p>The arrival of a stop codon at the A site (D)</p> Signup and view all the answers

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

<p>By hydrolizing GTP (C)</p> Signup and view all the answers

<p>It leaves the ribosome at the E site (C)</p> Signup and view all the answers

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

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

<p>To convey genetic information from DNA to ribosomes (D)</p> Signup and view all the answers

<p>Through the exit tunnel of the large subunit (A)</p> Signup and view all the answers

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

<p>Codons are triplets of nucleotides that specify amino acids (B)</p> Signup and view all the answers

<p>Aid in polypeptide folding (C)</p> Signup and view all the answers

<p>It codes for the amino acid methionine and signifies the start of translation (C)</p> Signup and view all the answers

<p>To synthesize mRNA from the DNA template (C)</p> Signup and view all the answers

<p>Multiple ribosomes translating the same mRNA (A)</p> Signup and view all the answers

<p>RNA polymerase does not need a primer to begin synthesis (A)</p> Signup and view all the answers

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

<p>61 (D)</p> Signup and view all the answers

<p>To decode the mRNA correctly into amino acids (A)</p> Signup and view all the answers

<p>It is crucial for RNA polymerase binding during initiation (C)</p> Signup and view all the answers

<p>Several codons can code for the same amino acid (B)</p> Signup and view all the answers

<p>Codons are read independently without sharing nucleotides (A)</p> Signup and view all the answers

<p>It indicates the end of the transcription process (B)</p> Signup and view all the answers

<p>They facilitate the binding of RNA polymerase to the promoter (C)</p> Signup and view all the answers

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

<p>Each mutant defect is linked to a specific gene responsible for enzyme production. (D)</p> Signup and view all the answers

<p>They categorically linked each mutant to specific deficiencies in distinct enzymes. (D)</p> Signup and view all the answers

<p>Genes may code for several polypeptides not identified as enzymes. (B)</p> Signup and view all the answers

<p>To carry the genetic instructions from DNA to ribosomes. (C)</p> Signup and view all the answers

<p>RNA usually consists of a single strand. (A)</p> Signup and view all the answers

<p>Pre-mRNA (A)</p> Signup and view all the answers

<p>The central dogma (A)</p> Signup and view all the answers

<p>Each amino acid is specified by a triplet of nucleotide bases. (D)</p> Signup and view all the answers

<p>Transcription occurs in the nucleus in eukaryotes. (B)</p> Signup and view all the answers

<p>Ribosomes facilitate the assembly of amino acids into polypeptide chains. (D)</p> Signup and view all the answers

<p>Different polypeptides can be produced from the same gene. (A)</p> Signup and view all the answers

<p>Providing a template for DNA replication. (D)</p> Signup and view all the answers

<p>The ordered sequence of amino acids specified by mRNA. (C)</p> Signup and view all the answers

<p>The relationship between mutant strains and enzyme deficiencies. (C)</p> Signup and view all the answers

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

<p>To remove introns and join exons (C)</p> Signup and view all the answers

<p>To control the access of RNA polymerase to the genes (B)</p> Signup and view all the answers

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

<p>To facilitate mRNA export from the nucleus and protect it (A)</p> Signup and view all the answers

<p>A three-nucleotide sequence on tRNA that pairs with mRNA codons (C)</p> Signup and view all the answers

<p>Repressor binding to the operator is reversible (C)</p> Signup and view all the answers

<p>It acts as a corepressor (B)</p> Signup and view all the answers

<p>To attach amino acids to the correct tRNA (D)</p> Signup and view all the answers

<p>To remove introns and join exons in premRNA (C)</p> Signup and view all the answers

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

<p>Lactose presence inactivates the repressor. (D)</p> Signup and view all the answers

<p>Each tRNA carries a specific amino acid to ribosomes (C)</p> Signup and view all the answers

<p>Most of the lac repressor is active. (C)</p> Signup and view all the answers

<p>Relaxed base pairing rules for the third base of codons (A)</p> Signup and view all the answers

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

<p>It activates the repressor by binding to its allosteric site. (B)</p> Signup and view all the answers

<p>Non-coding regions that remain untranslated (A)</p> Signup and view all the answers

<p>Repressible operons are inhibited by small molecules, while inducible operons are stimulated by them. (B)</p> Signup and view all the answers

<p>By correctly matching tRNA anticodons with mRNA codons (C)</p> Signup and view all the answers

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

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

<p>It hydrolyzes lactose into glucose and galactose. (C)</p> Signup and view all the answers

<p>About 27,000 nucleotide pairs (B)</p> Signup and view all the answers

<p>Transcription of the operon resumes. (D)</p> Signup and view all the answers

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

<p>They are removed during splicing (D)</p> Signup and view all the answers

<p>They function in splicing RNA molecules (B)</p> Signup and view all the answers

<p>In the nucleolus from rRNA transcribed and assembled with proteins (C)</p> Signup and view all the answers

<p>To induce enzyme synthesis by freeing the lac operon from the repressor (B)</p> Signup and view all the answers

<p>Only a small percentage of genes are expressed at any time (B)</p> Signup and view all the answers

<p>It relaxes chromatin structure, facilitating access for transcription (B)</p> Signup and view all the answers

<p>Histone modifications can recruit methylation enzymes to specific genes (B)</p> Signup and view all the answers

<p>The organization of chromatin directly influences transcriptional activity (A)</p> Signup and view all the answers

<p>It reduces gene expression in most cases (C)</p> Signup and view all the answers

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

<p>Densely condensed heterochromatin is usually not expressed (D)</p> Signup and view all the answers

<p>The ability of DNA to associate with histones (A)</p> Signup and view all the answers

<p>It proposes that specific modifications influence chromatin configuration and transcription (D)</p> Signup and view all the answers

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

<p>They usually remain methylated through successive cell divisions (B)</p> Signup and view all the answers

<p>It condenses chromatin, making it less accessible (B)</p> Signup and view all the answers

<p>Imbalance and diseases such as cancer (C)</p> Signup and view all the answers

<p>They regulate the accessibility of DNA for transcription. (C)</p> Signup and view all the answers

<p>Enhancers can be located thousands of nucleotides away from the promoter. (D)</p> Signup and view all the answers

<p>They assist RNA polymerase in the transcription of all protein-coding genes. (D)</p> Signup and view all the answers

<p>It produces different mRNA molecules from the same primary transcript. (D)</p> Signup and view all the answers

<p>They interact with DNA and help RNA polymerase bind to DNA. (D)</p> Signup and view all the answers

<p>By blocking access to the promoter region. (B)</p> Signup and view all the answers

<p>The length of the poly-A tail. (B)</p> Signup and view all the answers

<p>It protects mRNA from exonuclease degradation. (C)</p> Signup and view all the answers

<p>They identify which segments should be exons or introns. (B)</p> Signup and view all the answers

<p>Gene expression can be influenced by chromatin structure. (C)</p> Signup and view all the answers

<p>Eukaryotic mRNA has a poly-A tail that stabilizes it. (C)</p> Signup and view all the answers

<p>Chromatin-modifying proteins recruitment. (D)</p> Signup and view all the answers

<p>The full assembly of the initiation complex allows RNA polymerase to start moving along the DNA. (A)</p> Signup and view all the answers

<p>Regulatory proteins binding to UTR sequences (A)</p> Signup and view all the answers

<p>Sudden activation of translation initiation factors (B)</p> Signup and view all the answers

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

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

<p>Cell division, differentiation, and morphogenesis (B)</p> Signup and view all the answers

<p>To regulate gene expression affecting developmental fate (C)</p> Signup and view all the answers

<p>Changes in cell shape and motility (C)</p> Signup and view all the answers

<p>Different sets of gene activators (B)</p> Signup and view all the answers

<p>By relying on light to reactivate translation (C)</p> Signup and view all the answers

<p>Addition of phosphate groups (C)</p> Signup and view all the answers

<p>Resistance to proteasome degradation (C)</p> Signup and view all the answers

<p>1.5% (A)</p> Signup and view all the answers

<p>It increases their stability (A)</p> Signup and view all the answers

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

<p>All determined cells can be placed in any location within the embryo without losing their specific fate. (D)</p> Signup and view all the answers

<p>They stimulate normal cell growth and division. (C)</p> Signup and view all the answers

<p>They repair damaged DNA and prevent mutations. (B)</p> Signup and view all the answers

<p>p53 (B)</p> Signup and view all the answers

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

<p>To relay growth signals (C)</p> Signup and view all the answers

<p>Cells escape normal regulatory control. (B)</p> Signup and view all the answers

<p>Enhanced cell cycle stimulation (B)</p> Signup and view all the answers

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

<p>They have broken and rearranged chromosomes. (B)</p> Signup and view all the answers

<p>Contractile proteins myosin and actin (A)</p> Signup and view all the answers

<p>Hyperactive Ras protein with point mutations (C)</p> Signup and view all the answers

<p>Point mutations in proto-oncogenes (C)</p> Signup and view all the answers

<p>To act as an activator for several genes related to cell cycle regulation and DNA repair (D)</p> Signup and view all the answers

<p>Colorectal cancer often begins with a benign polyp that gradually accumulates multiple mutations. (D)</p> Signup and view all the answers

<p>At least a half dozen mutations including oncogenes and tumor suppressor genes (A)</p> Signup and view all the answers

<p>Tumor-suppressor mutations are recessive, requiring both alleles to be affected. (B)</p> Signup and view all the answers

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<p>It often starts from benign polyps that accumulate mutations. (A)</p> Signup and view all the answers

<p>At least one dominant mutation in an oncogene and several recessive mutations in tumor-suppressor genes. (D)</p> Signup and view all the answers

<p>By inducing apoptosis via activation of 'suicide genes' (D)</p> Signup and view all the answers

<p>Both alleles of tumor-suppressor genes typically need to be mutated for loss of function. (B)</p> Signup and view all the answers

The process by which DNA directs protein synthesis

The first stage of gene expression, where DNA is used as a template to make mRNA

The second stage of gene expression, where mRNA is used to build a protein

A series of chemical reactions that synthesize or degrade organic molecules.

Hereditary diseases resulting from the absence of an enzyme needed for a metabolic pathway.

The link between genotype (genes) and phenotype (observable traits).

The molecule that carries genetic information from DNA to the ribosome for protein synthesis.

Specific sequences of nucleotides along DNA strands that dictate protein synthesis

A hypothesis proposing that each gene is responsible for producing a single enzyme.

The refined hypothesis, suggesting that a gene codes for a single protein.

An improved hypothesis, stating that a gene codes for a single polypeptide chain.

Cellular structures that synthesize proteins.

The directional flow of genetic information: DNA to RNA to protein.

The set of rules that dictate how codons specify amino acids.

A sequence of three nucleotides that codes for a specific amino acid.

The strand of DNA that is used as a template for mRNA synthesis.

The initial RNA molecule transcribed from a gene.

A growth medium containing only essential nutrients for survival.

A bread mold used in genetic studies.

An organism with a genetic change affecting its traits.

The DNA strand used as a template for mRNA synthesis.

The DNA strand with the same sequence as the mRNA, except for uracil (U) in place of thymine (T).

The codon (AUG) signaling the beginning of protein synthesis.

A codon that signals the end of protein synthesis.

Multiple codons can code for the same amino acid.

The enzyme that carries out transcription.

A DNA sequence that signals the start of transcription.

The assembly of transcription factors and RNA polymerase II bound to a promoter.

A crucial promoter DNA sequence.

The way the sequence of codons is grouped in sets of three.

Proteins that mediate the binding of RNA polymerase and initiation of transcription in eukaryotes.

A condition caused by a mutation that adversely affects an organism's phenotype.

The replacement of one nucleotide and its partner with another pair of nucleotides in DNA.

A nucleotide-pair substitution that results in a codon coding for the same amino acid.

A nucleotide-pair substitution that changes one amino acid for another.

A nucleotide-pair substitution that changes an amino acid codon into a stop codon, leading to premature termination of translation.

A mutation caused by insertion or deletion of nucleotides that shifts the reading frame of the genetic code, leading to a drastically altered protein.

A mutation that occurs during DNA replication or repair without external influence.

A regulatory mechanism where the end product of a metabolic pathway inhibits the activity of an enzyme earlier in the pathway.

An operon whose transcription is activated by the presence of a specific inducer molecule.

An operon whose transcription is repressed by the presence of a specific repressor molecule.

The complex of DNA and proteins that make up eukaryotic chromosomes.

Chemical modifications to histone proteins that can influence gene expression.

RNA molecules that do not code for proteins but play important roles in gene regulation.

The process by which cells specialize and develop different functions.

The two parts of a ribosome, a large subunit and a small subunit, that come together during translation.

Three sites on a ribosome where tRNA molecules bind: the A site (aminoacyl tRNA), the P site (peptidyl tRNA), and the E site (exit).

The location on a ribosome where mRNA attaches, providing the genetic code for protein synthesis.

The process of linking amino acids together to create a polypeptide chain, catalyzed by the ribosome.

The first stage of translation, where the ribosomal subunits, mRNA, and the first tRNA come together to start protein synthesis.

Proteins that help assemble the translation initiation complex, bringing together mRNA, tRNA, and ribosomal subunits.

The stage of translation where amino acids are added one by one to the growing polypeptide chain.

Proteins that assist in the elongation phase of translation, ensuring accurate and efficient addition of amino acids.

The final stage of translation where the ribosome encounters a stop codon and releases the completed polypeptide chain.

Proteins that recognize stop codons in mRNA and trigger the release of the completed polypeptide chain.

Multiple ribosomes translating the same mRNA molecule simultaneously, increasing the production rate of proteins.

The process by which a polypeptide chain spontaneously folds into a specific three-dimensional structure.

Proteins that assist in the correct folding of other proteins.

Allolactose, a lactose analog, indirectly helps synthesize proteins by alleviating the negative effect of the repressor on the lac operon, allowing transcription to occur.

Different cells within an organism express different sets of genes despite having the same genome, leading to specialized cell functions.

Eukaryotic gene expression is regulated at multiple stages, including chromatin modifications, transcription, RNA processing, translation, and protein degradation.

The DNA in eukaryotic cells is packaged with proteins into a complex called chromatin, which can be condensed or relaxed to control gene expression.

The basic unit of chromatin, consisting of DNA wrapped around a core of histone proteins.

The addition of an acetyl group to lysine residues in histone tails neutralizes their positive charges, loosening chromatin structure and facilitating transcription.

The addition of a methyl group to cytosine bases in DNA can repress gene expression by condensing chromatin.

The idea that specific combinations of histone modifications, and their order, determine chromatin configuration and gene expression.

The inheritance of traits by mechanisms not directly involving the DNA sequence, such as chromatin modifications.

A phenomenon where methylation silences either the maternal or paternal allele of specific genes during development.

Chromatin modifications are often interconnected, with one enzyme influencing the activity of another, creating a complex regulatory network.

A model explaining how groups of genes (operons) are regulated in bacteria, often involving a single switch to control the expression of multiple related genes.

An operon responsible for synthesizing the amino acid tryptophan in E. coli. It's repressible, meaning its expression is turned off when tryptophan levels are high.

The trp repressor protein binds to the operator region of the trp operon, blocking RNA polymerase from transcribing the genes involved in tryptophan synthesis.

A small molecule, like tryptophan, that binds to a repressor protein, activating it and allowing it to bind to the operator, switching off gene expression.

An inducible operon responsible for metabolizing lactose in E. coli. It's activated by the presence of lactose.

The lac repressor protein binds to the operator region of the lac operon, blocking RNA polymerase from transcribing the genes involved in lactose metabolism, unless lactose is present.

A molecule, like allolactose (an isomer of lactose), that inactivates a repressor, allowing gene expression to occur.

Enzymes that are produced only when their specific substrate is present, often involved in catabolic pathways.

Enzymes that are produced only when their specific product is absent, often involved in anabolic pathways.

A mechanism of gene regulation where a regulatory protein (the repressor) actively blocks gene expression by binding to the operator region.

A site on a protein that binds a molecule, causing a conformational change in the protein's shape and altering its activity.

Regulation allows bacteria to only produce proteins when needed, conserving resources and energy.

A gene that acts as a tumor suppressor, preventing uncontrolled cell growth by halting the cell cycle, activating DNA repair, or inducing cell death through apoptosis.

A mutated gene that promotes uncontrolled cell growth and division, contributing to cancer development.

A gene that normally inhibits cell growth, but when mutated, can lead to uncontrolled cell growth and cancer development.

A type of programmed cell death that eliminates damaged or unwanted cells, preventing them from causing harm.

The development of cancer through the accumulation of multiple genetic mutations, typically involving both oncogene activation and tumor suppressor gene inactivation.

The control of gene expression through mechanisms that alter DNA accessibility or histone modifications, without changing the underlying DNA sequence.

Noncoding DNA segments that serve as binding sites for transcription factors, regulating gene expression.

Distal control elements that can be located thousands of nucleotides away from the promoter, enhancing the rate of transcription.

Transcription factors that increase the rate of transcription.

A process where different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons or introns.

The time an mRNA molecule remains intact in the cell, affecting the level of protein synthesis.

Nucleotide sequences in the 3 prime end of mRNA that affect mRNA stability.

Regulatory mechanisms that operate after transcription, allowing cells to fine-tune gene expression rapidly.

A process where signaling molecules from one cell trigger changes in another cell's developmental path.

The early molecular changes that commit a cell to a specific developmental path.

Proteins that give a cell its characteristic structure and function, determined by its specific role within a tissue.

The visible changes in a cell's structure and function that result from the expression of tissue-specific proteins.

Committed embryonic cells that will eventually develop into muscle cells.

Diseases where cells escape normal growth and division control mechanisms.

Normal cellular genes that regulate cell growth and division.

A G protein involved in relaying growth signals from a receptor to a cascade of protein kinases.

A transcription factor that inhibits the cell cycle and helps prevent cancer development.

A change in a single nucleotide within a gene.

An increase in the number of copies of a gene.

Factors like chemical carcinogens, X-rays, and viruses that can increase the risk of cancer.

The breakdown of mRNA molecules, often triggered by the transfer of a sequence from a short-lived mRNA to a stable one.

Controlling the process of protein synthesis from mRNA, often by blocking ribosome attachment to prevent protein production.

A string of adenine nucleotides at the end of mRNA, essential for initiating translation, but may need lengthening during embryonic development.

Proteins that activate or deactivate translation, allowing for simultaneous regulation of all mRNAs in a cell.

Maternal substances within an egg's cytoplasm that influence early development, often distributed unevenly, creating different cellular environments.

Proteins on the surface of cells that interact with other cells, providing signals that guide development.

Secreted molecules that influence cell development and growth, acting as signaling agents between cells.

Modifications that occur after translation to create functional proteins, including cleavage of pro-proteins and chemical modifications.

A small protein that marks other proteins for destruction by attaching to them, like a warning tag.

Giant protein complexes that recognize and degrade proteins tagged with ubiquitin, like a cellular garbage disposal.

The process that gives an organism its shape, involving the movement and arrangement of cells in three dimensions.