practice exam 2/3 !

<p>To serve as the binding site for RNA polymerase (B)</p> Signup and view all the answers

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

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

<p>About -40 to +40 base pairs (A)</p> Signup and view all the answers

<p>The DNA strand that is complementary to RNA (C)</p> Signup and view all the answers

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

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

<p>It aids in the transport of mRNA out of the nucleus. (B)</p> Signup and view all the answers

<p>By protecting mRNA from exonuclease degradation. (D)</p> Signup and view all the answers

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

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

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

<p>They are noncoding sequences that are removed from pre-RNA. (D)</p> Signup and view all the answers

<p>3’ splice site - AG/G (C)</p> Signup and view all the answers

<p>They help recruit small nuclear ribonuclear proteins (snRNPs). (D)</p> Signup and view all the answers

<p>They contain small nuclear RNAs (snRNAs) and associated proteins. (C)</p> Signup and view all the answers

<p>15-30% (A)</p> Signup and view all the answers

<p>The transcriptional state governed by genes (D)</p> Signup and view all the answers

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

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

<p>They bind to major grooves in target DNA (A)</p> Signup and view all the answers

<p>Every gene is regulated by multiple transcription factors (D)</p> Signup and view all the answers

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

<p>Multiple ribosomes bound to a single mRNA (C)</p> Signup and view all the answers

<p>Introns (B), Poly(A) tail (C)</p> Signup and view all the answers

<p>Facilitate RNA transport out of the nucleus (C)</p> Signup and view all the answers

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

<p>Duchenne Muscular Dystrophy (A)</p> Signup and view all the answers

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

<p>Semi-conservative replication (B)</p> Signup and view all the answers

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

<p>10,000-100,000 (A)</p> Signup and view all the answers

<p>It is the site where nucleotides are incorporated (C)</p> Signup and view all the answers

<p>It synthesizes the daughter strands of DNA (A)</p> Signup and view all the answers

<p>It extends RNA primers with new DNA nucleotides. (C)</p> Signup and view all the answers

<p>They stabilize the unwound DNA strands to prevent re-annealing. (C)</p> Signup and view all the answers

<p>Pre-replication complexes are activated by protein kinases. (C)</p> Signup and view all the answers

<p>It is synthesized discontinuously with Okazaki fragments. (A)</p> Signup and view all the answers

<p>Type I topoisomerases (B)</p> Signup and view all the answers

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

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

<p>It changes the amino acid to one with similar properties. (D)</p> Signup and view all the answers

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

<p>It is a permanent change in the DNA sequence. (A)</p> Signup and view all the answers

<p>A mutation that causes a different amino acid to be produced (B)</p> Signup and view all the answers

<p>Formation of toxic protein aggregates (A)</p> Signup and view all the answers

<p>Nondisjunction of chromosome 21 (C)</p> Signup and view all the answers

<p>Copy number variations (D)</p> Signup and view all the answers

<p>It is commonly duplicated in various cancers (C)</p> Signup and view all the answers

<p>To activate signaling pathways through ligand binding (D)</p> Signup and view all the answers

<p>The G protein activates the effector protein (C)</p> Signup and view all the answers

<p>Dissociation of G protein subunits (D)</p> Signup and view all the answers

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

<p>It activates adenylyl cyclase to increase ATP conversion to cAMP (B)</p> Signup and view all the answers

<p>It becomes inactive and associates with Gβγ. (B)</p> Signup and view all the answers

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

<p>G protein activation by the receptor. (B)</p> Signup and view all the answers

<p>It alters receptor conformation. (D)</p> Signup and view all the answers

<p>GDP is exchanged for GTP. (D)</p> Signup and view all the answers

<p>Activate or inactivate target proteins (D)</p> Signup and view all the answers

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

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

<p>Gi signaling pathway (A)</p> Signup and view all the answers

<p>Increased transcription of cAMP-sensitive genes (B)</p> Signup and view all the answers

<p>cGMP levels decrease (A)</p> Signup and view all the answers

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

<p>To cleave PIP2 into IP3 and DAG (D)</p> Signup and view all the answers

<p>Slower increase of cGMP leading to slower channel opening (A)</p> Signup and view all the answers

<p>They stimulate excessive cell proliferation (C)</p> Signup and view all the answers

<p>It triggers the activation of adenylyl cyclase or phospholipase C-beta. (B)</p> Signup and view all the answers

<p>Receptor nuclear factors (A)</p> Signup and view all the answers

<p>Regulation of gene transcription by phosphorylating transcription factors. (C)</p> Signup and view all the answers

<p>Conformational change that activates G-proteins. (A)</p> Signup and view all the answers

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

<p>Receptor-mediated endocytosis (B)</p> Signup and view all the answers

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

<p>The receptor phosphorylates itself (C)</p> Signup and view all the answers

<p>Ubiquitinates RTK for internalization (B)</p> Signup and view all the answers

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

The process of creating RNA from a DNA template in eukaryotic cells, using different RNA polymerases.

One of three RNA polymerases in eukaryotes; responsible for transcribing most protein-coding genes.

Proteins that bind to specific DNA sequences, influencing whether or not RNA polymerase can begin transcription.

A group of transcription factors that are essential for the initiation of transcription by RNA polymerase II; they assemble at the core promoter.

A critical General Transcription Factor (GTF) that binds to the promoter region of a gene, initiating the assembly of other transcription factors and RNA polymerase II. Specifically comprises TBP and TAFs.

Region in eukaryotic DNA near the start of a gene where general transcription factors bind and RNA polymerase II attaches to initiate transcription.

A specific DNA sequence in the core promoter region that is crucial for transcription initiation; usually recognized by the TBP protein.

A DNA sequence in eukaryotic promoters that overlaps with the transcription start site, assisting in RNA polymerase II binding.

A DNA sequence located downstream of the transcription start site, aiding in transcription initiation by RNA polymerase II.

Binding sites for specific transcription factors that control the level and timing of gene expression, located close to the core promoter.

A complex of proteins and enzymes that travel with RNA polymerase during transcription, carrying out mRNA processing steps.

A modified guanine nucleotide added to the 5' end of an mRNA molecule, protecting it from degradation and helping its export from the nucleus.

It protects the mRNA from degradation by exonucleases, helps transport the mRNA out of the nucleus, and plays a role in the initiation of translation.

A string of adenine nucleotides added to the 3' end of an mRNA molecule, protecting it from degradation and helping its export from the nucleus.

It protects the mRNA from degradation by exonucleases, helps its export from the nucleus, and plays a role in translation.

Non-coding DNA sequences within a gene that are removed during mRNA processing. They are not included in the final mature RNA product.

Coding DNA sequences within a gene that are retained and spliced together to form the mature RNA product.

The process of removing introns and joining exons together to form a mature messenger RNA molecule (mRNA).

The specific nucleotide sequence at the 5' end of an intron that marks the beginning of the intron and is crucial for recognizing and cutting it out during RNA splicing.

The specific nucleotide sequence at the 3' end of an intron that marks the end of the intron and is also important for splicing.

The nucleus is the control center of the cell, responsible for storing and protecting DNA and orchestrating the transcription of genetic information into RNA.

The nuclear envelope acts as a barrier, separating the nucleus from the cytoplasm, and controls the movement of molecules in and out of the nucleus.

Lamins are proteins that provide structural support for the nuclear envelope, maintaining its shape and anchoring chromatin to the inner membrane.

Nuclear trafficking refers to the controlled movement of molecules, such as proteins and RNA, between the nucleus and the cytoplasm, ensuring proper function of both compartments.

Proteins involved in transcription, translation, and other nuclear functions, and RNA products like mRNA, tRNA, and ribosomal RNA (rRNA), are transported through nuclear pores.

Bind to regulatory sites of a particular gene to either activate or repress transcription. They can be activators or repressors.

A DNA-binding motif in transcription factors, characterized by a zinc ion held by 2 cysteines and 2 histidines. It interacts with the major groove of DNA, recognizing specific base sequences.

A DNA-binding motif in transcription factors consisting of two α-helices connected by a loop. It binds to specific DNA sequences in the major groove.

The interplay between an individual's genetic makeup and their environment, influencing the manifestation of traits and diseases.

The study of heritable changes in gene expression that occur without alterations in the DNA sequence itself.

The regulation of which genes are activated or silenced, determining the types and amounts of proteins produced by a cell.

Proteins that bind to specific DNA sequences to control the initiation and rate of gene transcription.

Transcription factors are broadly classified into two categories: general transcription factors (GTFs) and sequence-specific transcription factors (SSTFs). GTFs are essential for the basic machinery of transcription, while SSTFs regulate the expression of specific genes.

An inherited disease causing thick, sticky mucus buildup in the lungs, pancreas, and other organs, leading to breathing problems and other complications.

A rare metabolic disorder where the body cannot break down homogentisic acid, leading to a buildup in the urine and connective tissues, resulting in dark urine and joint problems.

A group of diseases where abnormal proteins (amyloid) build up in organs, impacting their function.

A disorder affecting muscle movement and coordination caused by brain damage, leading to a range of physical disabilities.

A chronic inflammatory bowel disease affecting any part of the digestive tract, leading to abdominal pain, diarrhea, and weight loss.

The process of copying DNA to create two identical DNA molecules. This ensures genetic information is passed on during cell division.

A model of DNA replication where each new DNA molecule consists of one original strand and one newly synthesized strand. The original strand serves as a template for the new strand.

The Y-shaped structure formed during DNA replication where the parental DNA strands are separated, and new strands are synthesized.

A segment of DNA that is replicated independently. Eukaryotic genomes are divided into smaller replicons, each with its own origin of replication.

Localized sites within the nucleus where multiple replicons are actively engaged in DNA replication. These sites can be visualized using microscopy.

The process of DNA replication where one new strand (leading strand) is synthesized continuously, while the other strand (lagging strand) is synthesized discontinuously in short fragments called Okazaki fragments.

The new DNA strand synthesized continuously in a 5' to 3' direction towards the replication fork.

The new DNA strand synthesized discontinuously in short fragments (Okazaki fragments) away from the replication fork.

Short DNA fragments synthesized on the lagging strand during DNA replication.

A short RNA sequence that provides a starting point for DNA polymerase to begin synthesizing new DNA.

A change in a single base pair in the DNA sequence.

A point mutation that results in a change of the amino acid encoded by the DNA.

A point mutation that creates a premature stop codon, resulting in a truncated protein.

A mutation caused by an insertion or deletion of a number of nucleotides that is not a multiple of three. This shifts the reading frame, changing the codons and the amino acid sequence.

Changes in the amount of genetic material at a specific location, including insertions, deletions, duplications, and repeat expansions.

G protein-coupled receptors (GPCRs) are the largest family of membrane proteins, characterized by their 7 transmembrane helical domain structure. They are coupled to cytoplasmic G proteins, which consist of three subunits (α, ß, γ) and use GTP to activate effector proteins, triggering second messengers.

GPCRs can be activated by a diverse range of ligands, including small molecules like amino acids and their derivatives (e.g., acetylcholine, epinephrine, dopamine), gases (e.g., NO, CO), steroids, lipids (e.g., eicosanoids), peptides, and proteins.

1. Ligand binding to the receptor changes its conformation, increasing its affinity for G protein.
2. G protein binds to the receptor, causing a conformational change in Gα.
3. GDP is exchanged for GTP, activating the G protein.
4. GTP-Gα dissociates from Gßγ and binds to an effector protein, either activating or inhibiting it.

GPCRs can activate a range of effector proteins, including adenylyl cyclase (which converts ATP to cAMP), phospholipase C, and cGMP phosphodiesterase.

G proteins act as molecular switches. When activated by binding GTP, they relay the signal from the GPCR to downstream effector proteins. The Gα subunit can activate or inhibit effector proteins depending on the specific G protein involved.

When a ligand binds to the extracellular domain of a G protein-coupled receptor, it changes the receptor's shape, increasing its affinity for a G protein.

The binding of a G protein to an activated receptor causes a conformational change in the Gα subunit, leading to GDP being replaced by GTP, activating the G protein.

The activated GTP-bound Gα subunit dissociates from the Gßγ subunits and binds to an effector protein, which can activate or inhibit cellular processes.

The Gα subunit can inactivate itself by hydrolyzing GTP to GDP, causing it to re-associate with Gßγ and decreasing its affinity for the effector protein.

GPCRs become desensitized by phosphorylation by G protein-coupled receptor kinase (GRK), which allows arrestin binding and inhibits G protein interactions.

Small molecules produced inside cells that relay and amplify signals from outside the cell, often generated by effector enzymes.

Enzymes that are activated by G proteins and produce second messengers, which are important for signal transduction pathways.

Inositol triphosphate (IP3) is a second messenger that triggers the release of calcium ions from intracellular stores.

Diacylglycerol (DAG) activates protein kinase C (PKC) by binding to its regulatory domain.

Protein kinase C (PKC) is a kinase enzyme that is activated by DAG and calcium ions. It phosphorylates target proteins, leading to various biological effects.

A large family of transmembrane proteins that are coupled to G proteins. GPCRs are involved in diverse cellular processes by mediating signaling pathways that involve second messengers. They are characterized by their 7 transmembrane helical domain structure.

A second messenger produced from ATP by adenylyl cyclase, an effector enzyme. cAMP plays a role in diverse cellular processes, including signal transduction, gene transcription, and metabolism.

A second messenger produced from GTP, often used in sensory systems, like vision. It helps regulate the activity of certain ion channels and is directly broken down by cGMP phosphodiesterase.

Two important second messengers produced by the cleavage of PIP2 by phospholipase C (PLC). IP3 mobilizes Ca2+ from intracellular stores, while DAG activates protein kinase C.

The process where an activated receptor protein-tyrosine kinase (RTK) adds phosphate groups to its own intracellular domain.

Proteins that bind to phosphorylated RTKs and become activated, triggering a cellular response.

Specialized regions found in relay proteins that allow them to interact with phosphorylated tyrosine residues on RTKs.

An E3 ubiquitin ligase that attaches ubiquitin to RTKs, marking them for internalization and degradation.

There are various types of relay proteins, including adaptors, docking proteins, transcription factors, and enzymes.

RTKs are transmembrane receptors that have intrinsic tyrosine kinase activity, meaning they can add phosphate groups to tyrosine residues on proteins. They are involved in various signalling pathways, including cell growth, proliferation, and differentiation.

Ligand-gated channels are proteins that act as gates in the cell membrane, allowing the passage of ions like sodium, potassium, and calcium. They are activated by the binding of a specific ligand, allowing for rapid changes in membrane potential and cell function.

Steroid hormone receptors are intracellular proteins that bind to steroid hormones, like testosterone or estrogen. Upon binding, they act as transcription factors, controlling gene expression and regulating cellular processes.

cAMP (cyclic AMP) is a second messenger that is activated by the G-protein coupled receptor (GPCR) pathway. It is produced by adenylyl cyclase, an effector enzyme. cAMP activates Protein Kinase A (PKA), which phosphorylates target proteins, leading to a range of cellular responses like increased glucose production.

cGMP (cyclic GMP) is a second messenger activated by certain GPCRs. It is produced by guanylyl cyclase and can be degraded by cGMP phosphodiesterase. cGMP plays a role in vision, mediating light-induced changes in retinal cells. It also affects smooth muscle relaxation and vascular dilation.