Cell Bio Final

What are gap junctions?

(communicating junctions) provide cytoplasmic channels between adjacent cells. Made up of connexons

Which of the following descriptions better applies to the cisternal maturation model rather than the vesicle transport model for the organization of the Golgi apparatus? a. Golgi cisternae are static compartments. b. A cis Golgi cisterna becomes a medial cisterna which becomes a trans cisterna. c. Golgi cisternae exchange material by both forward- and backward-moving transport vesicles d. Any protein that passes through the Golgi apparatus should be incorporated into transport vesicles several times.

A cis Golgi cisterna becomes a medial cisterna which becomes a trans cisterna.

Which of the following descriptions better applies to the cisternal maturation model rather than the vesicle transport model for the organization of the Golgi apparatus? (A) Golgi cisternae are static compartments. (B) Golgi cisternae exchange material by both forward- and backward-moving transport vesicles. (C) A cis Golgi cisterna becomes a medial cisterna which becomes a trans cisterna. (D) Any protein that passes through the Golgi apparatus should be incorporated into transport vesicles several times

A cis Golgi cisterna becomes a medial cisterna which becomes a trans cisterna.

During a flow cytometry analysis of the cell cycle of a proliferating cell population, the distrubution of cells obtatined shows which of the following? A. G2+M is longer than G1 B. The number of cells is similar in G1 and S phase C. A greater number of cells in G1 than in G2+M D. The number of cells is similar in G1 and G2+M phase E. A fewer number of cells in G1 than in G2+M

A greater number of cells in G1 than in G2+M

What is the name of the separate regulatory protein complex that initiates the metaphase to anaphase transition in mitosis

APC/C

How can p21, p53, cdc25, and ATM lead to arrest of the cell cycle? Please explain what these molecules do and how they are affected by each other.

ATM is a protein that senses breaks in DNA and then triggers the activation of either of two pathways (depending on whether the cell is in G1 or G2.) .In one pathway, cdc25 becomes phosphorylated and thus gets inactivated, meaning that it cannot dephosphorylate cdk's. Since the cdk's remain in their phosphorylated and inactive state, they do not move the cell through the next checkpoint.In the other pathway, ATM causes the stabilization of p53, which then acts as a transcription factor inducing the synthesis of p21, a cdk inhibitor.Inhibition of cdk's then causes the cell cycle to stall.

Unlike a myosin head, a kinesin head is tightly bound to its cytoskeletal track when bound to what? a. No nucleotide b. GTP c. ADP d. ATP e. GDP

ATP

Which of the following would you NOT expect to find in a bacterial cell? A. Swimming using flagella B. Having a cell wall around the plasma membrane C. ATP production in mitochondriaD. Protein production on the ribosome E. Sexual exchange of DNA with other bacteria

ATP production in mitochondriaD. Protein production on the ribosome

A person who suffers angina (chest pain associated with cardiac problems) sometimes place a small pill containing nitroglycerine under their tongue. As the nitroglycerine decomposes, a small amount of nitric oxide (NO) is produced which lowers blood pressure, relieving the angina by a series of events that ultimately leads to muscle relaxation. This drug acts mostly by dissociating what type of filament complex? (A) Actin and myosin (B) Tubulin and dynein (C) Keratin and vimentin (D) Actin and tubulin

Actin and myosin

Malformation of which cytoskeletal structures may be linked to an inability to contract muscle? (A) Microtubules (B) Intermediate filaments (C) Actin filaments (Microfilaments) (D) Centrioles

Actin filaments (Microfilaments)

Protein phosphorylation is commonly involved with all the following except: (A) Enzyme activation. (B) Activation of G protein-coupled receptors. (C) Activation of receptor tyrosine kinases. (D) Activation of protein kinase molecule

Activation of G protein-coupled receptors.

Which of the following events normally activates a GTP-binding protein? a. Pi release after GTP hydrolysis b. Activation of an upstream GTPase-activating protein c. Phosphorylation of a bound GDP molecule by an upstream phosphorylase d. Activation of an upstream guanine nucleotide exchange factor e. GTP hydrolysis by protein

Activation of an upstream guanine nucleotide exchange factor

Cleavage of the ICAD leading to DNA fragmentation is achieved by

Active executioner caspase (caspase-3)

What are the role of snare proteins in vesicle transport?

Additional recognition occurs. once rab protiens and teathering protiens have interacted snare proteins stabalize docking proteins

What does glycoslyation do to a protein?

Adds sugar through the use of glycosylating enzymes not found in the cytosol

Which of the following cell junctions uses cadherin cell adhesion molecules to anchor the actin cytoskeleton?

Adherens Junctions

Three bacteria samples are harvested, each from different boiling volcanic mud pots on three different continents. To assess their evolutionary relationships, the researcher should do what? a. Identify the structures they use for motility. b. Compare their nutrient sources. c. Analyze the differences in their genes. d. Compare the molecular makeup of their outer cell wall. e. Identify the other species living nearby in the same ecosystem

Analyze the differences in their genes

Which phase in the M phase of mitosis do the sister chromatids separate to form two daughter chromosomes which are pulled slowly towards the spindle poled.

Anaphase

Cells shrink and condense, cytoplasm collapse, nuclear envelope disassembly and nuclear chromatin condensing is what?

Apoptosis

Compared to cells of a normal tissue, which of the following occurs less frequently in cells within a solid tumor? a.Cell division b.Miotic recombination c.Apoptosis d.Necrosis e.Stress

Apoptosis

Which model organism has provided the most information about plants, including flower development? a. Arabidopsis thaliana b. Caenorhabditis elegans c. SARS-CoV-2 Coronavirus d. Drosophila melanogaster

Arabidopsis thaliana

In a plant's life cycle, hormones play a critical role in the regulation of growth and behavioral processes. Which of the following hormones function in phototropism and gravitropism? a. Raf MAP kinase b. Auxin c. Estrogen d. Receptor tyrosine kinase e. GTPase-activating hormone

Auxin

The ___ ____ underlie epithelia and are interposed between two cell sheets (as in kidney glomerulus). filtration mechanism

Basal lamina

Though cyclopamine is known to cause birth defects as a cancer therapeutic, recently it has been nonetheless used to treat basal cell carcinoma of the skin. Why is it preferred? (A) Because it binds to and inhibits Smoothened, resulting in the down regulation of Hedgehog signaling 4 (B) Because it kills all cells (C) Because it stops mitosis (D) Because activates apoptosis

Because it binds to and inhibits Smoothened, resulting in the down regulation of Hedgehog signaling 4

Why do cells not have membrane transport proteins for O2? a. Because they need to keep the oxygen concentration low inside the reducing environment of the cell b. Because oxygen can dissolve in the lipid bilayer and diffuse in and out rapidly without the need for a transporter c. Because oxygen can dissolve in water and leak in via water channels d. Because oxygen is transported in and out of the cell in special oxygen-carrying proteins such as hemoglobin e. Because oxygen transport across a membrane is energetically unfavorable

Because oxygen can dissolve in the lipid bilayer and diffuse in and out rapidly without the need for a transporter

What do adherins do?

Bind through actin filaments and allows for the ability to have tensile strength Composed of E.cadherins, Viniculin and Catenin protiens which are calcium dependent proteins

How are proteins integrated into the membrane?

By a threading like motion where they are build into the membrane

How are antibody-producing hybridoma cell lines immortalized to provide an unlimited source of monoclonal antibodies? Select one: a. By cell fusion b. By ectopic expression of telomerase c. By irradiation d. By transformation with a retrovirus e. By overproduction of introduced oncogenes

By cell fusion

1.Put the steps of the co-translational translocation protein targeting process in the correct order and choose the corresponding answer choice below. (1) SRP delivers the ribosome to SRP receptor in the ER. (2) The polypeptide penetrates the ER membrane. The SRP is released. (3) Free ribosomes synthesize a piece of signal peptide (signal sequence). (4) Signal peptidase removes the signal sequence within the ER lumen. (5) Signal recognition particle (SRP) binds to the signal sequence of the new peptide on the ribosome. (6) Translation continues until the stop codon. a. 1, 2, 3, 4, 5, 6 b. 3, 5, 1, 2, 4, 6 c. 5, 1, 4, 3, 6, 2 d. 3, 5, 2, 1, 4, 6

C?

What binds to the Cylclin + Cdk distorting the active sit of Cdk and inserts itself into teh ATP binding site to inhibit enzyme activity?

CKI p27

A respiring mitochondrion will passively export to the cytoplasm which of the following? a. H+ b. ADP c. O2 d. CO2

CO2

A respiring mitochondrion will passively export to the cytoplasm which of the following? (A) O2 (B) H+ (C) ADP (D) CO2

CO2

A vesicle containing proteins that need to return to the ER would be coated with which of the following? (A) COP I (B) COP II (C) Clathrin (D) A Vesicle never returns to the ER

COP1

In which one of the following organisms is systemic RNAi possible through feeding the animal with the RNA?

Caenorhabditis elegans

Membrane receptors that attach phosphates (P) to specific aminoacids in proteins are: (A) Not found in humans. (B) Called receptor tyrosine-kinases. (C) A class of GTP G-protein signal receptors. (D) Important in yeast mating factors that contain amino acids

Called receptor tyrosine-kinases.

In contrast to transporters, the channel proteins in cellular membranes ____ a. Interact strongly with the solute(s) that they transport. b. Can only mediate active transport. c. Can only mediate passive transport. d. Form pores that are always open.

Can only mediate passive transport.

Regarding cancer cells and their use of glucose, which statement is true? a.Cancer cells use glucose mainly in the oxidative phosphorylation pathway. b.Cancer cells use glucose to support the production of raw materials that enable cellular proliferation. c.Cancer cells use glucose so that they can oxidize it into CO2. d.Cancer cells use glucose mainly in the mitochondria. e.Cancer cells use glucose to induce aerobic respiration.

Cancer cells use glucose to support the production of raw materials that enable cellular proliferation.

In the extrinsic pathway, the end result is the assembly of a large death-inducing signaling complex (DISC) composed of multiple copies of Fas, FADD, and ________

Capspase 8

What is the most common cancer in humans? a. Lymphoma b. Myeloma c. Carcinoma d. Leukemia e. Sarcoma

Carcinoma

When cyclin forms a complex with _____ the protein kinase is activated to trigger specific cell-cycle events. (ex.mitosis, G1 etc.)

Cdk

M-cyclins activate Cdks that do what? a. Cdks that stimulate chromosome duplication b. Cdks that promote DNA replication c. Cdks that trigger progression through Start d. Cdks that remain at elevated levels until mitosis e. Cdks that stimulate entry into mitosis at the G2/M transition

Cdks that stimulate entry into mitosis at the G2/M transition

Animal cells do not have _______and _____ but plant cells do. (A) Mitochondria and cell membrane (B) Cell wall and chloroplast (C) Ribosomes and endoplasmic reticulum (D) Vacuole and cytoplasm

Cell wall and chloroplast

How do Chaperones recognize proteins that are NOT completely folded? (so they can bind to those proteins to help them fold) A) Chaperones can recognize the shape of unfolded proteins. B) Chaperones can recognize the shape of folded proteins .C) Chaperones bind to patches of hydrophobic amino acids on other proteins. D) Chaperones bind to patches of hydrophilic amino acids on other proteins .E) Chaperones bind equally well to a folded or unfolded protein.

Chaperones bind to patches of hydrophobic amino acids on other proteins.

Which of the following occurs in both photosynthesis and respiration? (A) Chemiosmosis (B) Glycolysis (C) Calvin Cycle (D) Krebs Cycle

Chemiosmosis

Each chromosome consists of 2....... a. chromatids b. daughter cells c. centrofibers d. centrioles

Chromatids

Where do vesicle enter in the golgi?

Cis face that faces the ER

Which of the following statements about Clathrin coated vesicles is FALSE? A. Clathrin is a protein that is found in the cytosol B. Clathrin coats assemble on the TGNC. Clathrin coats assemble on the plasma membrane D. Clathrin coated vesicles transport proteins from the ER to the cis-Golgi

Clathrin coated vesicles transport proteins from the ER to the cis-Golgi

What is important about adaptor proteins?

Conecting point between clatherin and the vesicle and important for cargo selection. Secure the clathrin cage to the membrane. Makes sure the appropriate cargo is in the vesicle. Use proteins destined for targets on them. Have the transport signal

What are tight junctions?

Creates a nearly water tight barrier between cells. Barrier to lateral movement of membrane proteins. Made from two proteins clavdins and occludins. Proteins bound on the cytosolic side are actin filaments Found in blood vessels, respiratory cells

What is a phosphate that increases Cdk activity?

Csc25

What phosphorylates proteins involved in rearrangeing chromosomes and the cytoskelateon?

Cyclin dependent kinase

Though cyclopamine is known to cause birth defects as a cancer therapeutic, recently it has been nonetheless used to treat basal cell carcinoma of the skin. For what cancers are cyclopamine used as a treatment and why is it preferred?

Cyclopamine, often isolated from the meadow lily, is a steroidal alkaloid and a naturally occurring chemical that is often used to treat cancers that are associated with increased Hedgehog signaling. This is the case, because the chemical tightly binds to and inhibits Smoothened, which results in the down regulation of Hedgehog signaling.

What is a component of he electron transport chain that also plays a role in apoptosis

Cytochrome c

In the intrinsic pathway of apoptosis, the mitochondria releases a protein into the cytosol, which binds to the adaptor protein Apaf1. Apaf1 then oligomerizes into a wheel-like assembly called an apoptosome, which recruits initiator caspase-9 proteins. What is the name of this protein?

Cytocrome C

Which phase in M phase does the cytoplasm divide into two by a contractile ring of actin and myosin filaments, pinching the cell in two.

Cytokinesis

In cells irradiated with ultraviolet light, where is cytochrome-c located?

Cytosol

What was the original function of the CRISPR system? a. Defending bacteria from viral infections b. Defending bacteriophages from bacteria c. Defending leukocytes from viruses d. Defending spider-man against venom

Defending bacteria from viral infections

How does the expression of Delta on the surface of a cell activate the expression of certain genes in the nucleus of its neighboring cell? a. Delta binding leads to the proteolytic cleavage of Notch and inhibition of its activity as a transcriptional repressor, leading to the activation of target genes. b. Delta binding releases the intracellular tail of Notch, which enters the nucleus and converts a transcriptional repressor into a transcriptional activator. c. Delta binding activates Notch, which activates a transcriptional activator through the JAK-STAT pathway. d. Delta binding leads to Notch-mediated recruitment of protein complexes to the plasma membrane, resulting in the degradation of a transcriptional repressor. e. Delta binding leads to the stabilization of a cytoskeleton-associated transcriptional activator.

Delta binding releases the intracellular tail of Notch, which enters the nucleus and converts a transcriptional repressor into a transcriptional activator.

During the initial step of apoptosis, initiator caspases are activated by:

Dimerization

What does Contact dependent signaling in a cell require?

Direct interaction between a signaling receptor and the target cell

What squeezes the clatherin coated vesicle off from the rest of the membrane?

Dynamin

Which of the following proteins determines which protein lives or dies by ubiquitin-mediated degradation? A) HSP-70 B) Ubiquitin Activating Enzyme C) E2 D) E3 E) Proteasome core

E3

Which of the following can lead to p53 stabilization and activation? a.DNA damage b.p53 mutation c.Normoxia d.E6 and E7 viral proteins e.Chromosomal stability

E6 and E7 viral proteins

Which characteristic is among the hallmarks of cancer cells? a.Manipulation of the tissue environment, inducing an immune response b.Evasion of cell-death signals c.Unaltered cell metabolism d.Altered homeostasis that results in cells dividing at a faster rate, inducing apoptosis e.Maintenance of the limits to cell proliferation

Evasion of cell-death signals

In general, which of the following sequential barriers to metastasis is the easiest to overcome for cancer cells? a.Survival of cells in the foreign tissue b.Initial growth of cells in the foreign tissue c.Persistence of growth in the remote site d.Exit from the blood into a remote tissue or organ e.Vessel entry through acquisition of local invasiveness

Exit from the blood into a remote tissue or organ

What is the "realm" that consists of many different proteins and polysaccharides, a complex intricate network of macromolecules, and rock hard structures like bones or teeth?

Extracellular matrix

What is the name of the ligand on the killer lymphocyte for cell surface death receptors?

FAS ligand

The water-soluble phosphate group of the lipid bilayer _____ a. Faces inside the cell b. Faces outside the cell. c. Faces both inside and outside the cell. d. Lies inside the lipid bilayer.

Faces outside the cell.

Glycosylation takes place in the endoplasmic reticulum. (A) True (B) False

False

Once activated, a GPCR molecule can activate multiple molecules of G protein to amplify the incoming signal.

False

Plant cells lack microtubules.

Flase

What is the most energetically unfavorable movement that a membrane protein can experience in the lipid bilayer? a. Rotational diffusion b. Lateral diffusion c. Flip-flop d. Flexion

Flip-flop

Protein A is marked with a fluorescent marker. When excited with green light, it emits blue light. Protein B is also marked with a fluorescent marker. When it is excited by blue light, it emits violet light. When these proteins come into close proximity to one another while excited by green light, violet light will be emitted. What is this an example of? a. Fluorescence resonance energy transfer (FRET) b. Fluorescence recovery after photobleaching c. Fluorescence protein excitation d. Fluorescence-tagged resolution

Fluorescence resonance energy transfer (FRET)

What is the specialty of microtubles?

For transport this is accomplished through differences in polarity of each end

What role does Vimentin filaments play in the cytoskeleton?

Found in muscle and connective tissues and are the support cells of the nervous system

What is the gap phase between M and S phase in cell cycle?

G1

Which of the following phases of the cell cycle make up what is known as interphase?

G1, S, and G2

What is the late G1 rising which Cdk complex triggers through the start transition.

G1/S-Cdk

What is the gap phase between S and Mitosis in the cell cycle?

G2

What are large highly charged polysaccharides that are usually covalently linked to proteins in the form of proteoglycans in the ECM?

GAGs

What are the three major classes of macromolecules in the ECM

GAGs, Fibrous proteins (collagen fam), non collagen glycoproteins

__ are delays in the cell cycle to allow cell growth.

Gap Phases

Which of the following is not an anhoring junction?

Gap junctions

The light used to excite a fluorescent molecule carries ___________ energy and has a ___________ wavelength compared to the light that is then emitted from the molecule. a. Greater; longer b. Greater; shorter c. The same amount of; shorter d. Less; longer e. Less; shorter

Greater; shorter

What are SAM complexesd role in the mitocondria

Help fold proteins in the outer membrane,

What is a nonpreventable cause of cancer? a.Cigarette smoke b.UV radiation c.Hereditary predisposition d.Diet e.Viruses

Hereditary predisposition

In healthy cells a caspase-activated DNase (CAD) is held in an inactive state by an inhibitor protein called?

ICAD

Which of the following describes cell communication systems? (A) Cell signaling evolved more recently than systems such as the immune system of vertebrates. (B) Communicating cells are usually close together. (C) Most signal receptors are bound to the outer membrane of the nuclear envelope. (D) Lipid phosphorylation is a major mechanism of signal transduction. (E) In response to a signal, the cell may alter activities by changes in cytosol activity or in transcription of RNA

In response to a signal, the cell may alter activities by changes in cytosol activity or in transcription of RNA

Which of the following is NOT a carcinogenic agent? a. Tobacco b. Inherited genetic defect c. UV-light d. X-rays

Inherited genetic defect

What are the three additional classes of transmembrane adhesion proteins that mediate more transient cell adhesion?

Integrins, selectins, and immunoglobins

Which cytoskeletal filament is abundant in an animal cell nucleus? a. Intermediate filaments b. Microtubules c. Actin filaments d. Septins e. Spectrin filaments

Intermediate filaments

The ___ ___ of apoptosis is the intracellular apoptotic stimuli which causes mitochondria to release cytochrome c.

Intrinsic Pathway

What role does the nuclear lamins play in the cytoskeleton?

Involved in strengthening the envelope of nucleus

Which of the following descriptions does not apply to the Wee1 protein? a. This protein kinase inhibits Cdk activity. b. M-Cdk activates Cdc25 and inhibits Wee1. c. It activates M-Cdk complexes. d. The phosphatase Cdc25 dephosphorylates sites phosphorylated by Wee1.

It activates M-Cdk complexes.

The water-splitting step in photosynthesis does which of the following? (A) It is catalyzed by an iron-sulfur cluster. (B) It consumes H+ and therefore contributes to the proton gradient across the thylakoid membrane. (C) It occurs on the stromal side of the thylakoid membrane. (D) It generates all the O2 in the Earth's atmosphere

It generates all the O2 in the Earth's atmosphere

The water-splitting step in photosynthesis does which of the following? a. It occurs on the stromal side of the thylakoid membrane. b. It generates all the O2 in the Earth's atmosphere c. It is catalyzed by an iron-sulfur cluster. d. It consumes H+ and therefore contributes to the proton gradient across the thylakoid membrane.

It generates all the O2 in the Earth's atmosphere

What is NOT true of the plasma membrane? a. It is totally impermeable. b. It contains proteins that move materials across the plasma membrane. c. It contains enzymes that catalyze reactions within the cell. d. It is made of molecules that are both hydrophilic and hydrophobic. e. It allows waste materials to be removed from the cell.

It is totally impermeable.

What is true of overproduction of cadherins such as E-cadherin? A. It is often found in cancers originating from epithelia. B. It is induced by the transcription regulatory protein Twist. C. It induces epithelial-mesenchymal transition. D. It leads to stronger cell-cell adhesion.

It leads to stronger cell to cell adhesions

Proteins are synthesised on ribosomes in the cell cytoplasm, and must be targeted to the appropriate compartment of the cell by special targeting sequences. What is likely to be the fate of a protein that contains no such targeting sequence? a. It will be replicated b. It will be degraded immediately c. It remains in the cytoplasm d. It will become an antibody

It remains in the cytoplasm

Synaptic signaling between adjacent neurons is like hormone signaling in which of the following ways? (A) It sends its signal molecules through the blood. (B) It sends its signal molecules quite a distance. (C) It requires calcium ions. (D) It requires binding of a signaling molecule to a receptor. (E) It persists over a long period.

It requires binding of a signaling molecule to a receptor.

Which of the following is NOT true about nanopore sequencing? a. It can be used for extremely long strands of DNA. b. It can be performed in a handheld device. c. It utilizes an electric current to pull DNA though a protein pore. d. It requires deoxyribonucleotides that have a fluorescent tag. e. It can detect modified nucleotides.

It requires deoxyribonucleotides that have a fluorescent tag.

Which is a type of intermediate filament found in epithelial cells? (A) Keratin (B) Dynein (C) Myosin (D) Kinesin

Keratin

The endoplasmic reticulum (ER) in animal cells uses microtubule motor proteins to adopt and maintain its extended, reticular organization. The motor protein __________is most likely the carrier of vesicles traveling from the ER (minus) towards the Golgi apparatus (plus). A) Actin (B) Myosin (C) Dynein (D) Kinesin (E) Tubulin

Kinesin

Why is the polarity impoertant fir microtubles in terms of motor proteins?

Kinesin walk towards the positive end while dynein walk towards the negative end

A signal molecule that binds to a plasma-membrane protein is a (A) Ligand (B) Second messenger (C) Protein kinase (D) Receptor protein

Ligand

What is the main function of lipid droplets in the cell?

Lipid storage

Segregation and cell division occurs during which phase?

M phase

Entry into S phase leads to inactivation of ____ which unwind DNA and recruit other proteins to initiate DNA replication.

MCM Helicase

Which Phase in M phase of mitosis do the chromosomes align at the equator of the spindle. The kinetochore microtubules attach sister chromatids to opposite poles of the spindle.

Metaphase

Which structure is used in muscle contraction?

Microfilaments

What enables the movement of intracellular cargo from the center of the cells to its perifery?

Microtubles

A couple is told by their doctor that the reason why they cannot have children is that the sperm of the male lack motility because it does not have the structures responsible for propulsion. Which cellular structures are likely to be the underlying cause of this lack of motility? (A) Microtubules (B) Golgi apparatus (C) Endoplasmic reticulum (D) Vacuoles

Microtubules

Which of the following cytoskeletal components undergo dynamic polymerization and depolymerization through GDP-GTP cycling, and are typically comprised of alpha and beta subunits? (A) Microfilaments (B) Crescentin (C) Microtubules (D) Intermediate filaments (E) Actin

Microtubules

Where does cellular respiration take place in the cell? (A) Cell Membrane (B) Nucleus (C) Mitochondria (D) Vacuole

Mitochondria

Which two organelles do we find ATP Synthases? (A) Mitochondria and Chloroplasts (B) Chloroplasts and Nuclei (C) Mitochondria and Nuclei (D) Golgi Apparatus and Chloroplasts (E) Golgi Apparatus and Mitochondria

Mitochondria and Chloroplasts

The intrinsic pathway of apoptosis dictates that proteins be released from which of the following?

Mitocondria

____ bind to cell-surface receptors to initiate intracellular signaling pathways.

Mitogen

What role does keratin filaments play in the cytoskeleton?

Most abundent in epithelial cells.

How does the cell membrane on the exterior of the cell differ from the membranes that envelope organelles inside the cell? a. Organelle membranes are not semipermeable. b. Organelle membranes have a different signature of proteins floating in the bilayer. c. Organelle membranes are not composed of a phospholipid bilayer. d. Organelle membranes aren't really membranes at all.

Organelle membranes have a different signature of proteins floating in the bilayer.

Which of the following describes the fluid-mosaic model of the plasma membrane structure? a. Phospholipid monolayer with embedded proteins b. Triglyceride bilayer with embedded proteins c. Phospholipid bilayer with embedded proteins d. Triglyceride monolayer with embedded proteins e. Phospholipid trilayer with embedded proteins

Phospholipid bilayer with embedded proteins

Which component of the chloroplast electron transport chain donates electrons to reduce ferredoxin? a. Photosystem I b. Antenna chlorophyll c. Plastocyanin d. P680 chlorophyll e. Photosystem II

Photosystem II

Which phase in M phase in mitosis is replicated chromosomes (consisting of of two closely associated sister chromatids) condense. Mitotic spindle assembles between two chromosomes.

Prophase

What role does neurofilaments play in the cytoskelton?

Provide the structural support of neurons

Which cellular function may be disrupted because of a malformation of the intermediate filaments? (A) Resilience to compression forces (B) Transport of chemicals (C) Formation of spindle (D) Ability to divide

Resilience to compression forces

Chromosome duplication occurs during which phase?

S Phase

What is the Cdk complex that formulate in G1 and trigger DNA replication, as well as early meiotic events.

S-Cdk

How are SRPs used in relation to ribosomes

SRP is connected to ribsome. where it then fuzes with a receptor on the ER membrane. The trnaslates the protein and releases the protein into the ER lumen

Paracrine signaling involves (A) Secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid. (B) Requires nerve cells to release a neurotransmitter into the synapse. (C) Occurs only in paracrine yeast cells. (D) Has been found in plants but not animals.

Secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid.

What determines whether a cell is a target cell for a particular signal molecule? (A) Phosphorylation cascade (B) cAMP (C) Signal receptors (D) Phosphatase

Signal receptors

Which technique generates a complete list of all major mRNAs expressed in every cell type in an organism? a. Ribosome profiling b. Illumina sequencing c. RT-PCR d. Nanopore sequencing e. Single-cell RNA sequencing

Single-cell RNA sequencing

Which statement about Chaperones is false? A) Most proteins need the assistance of Chaperones to fold inside the cell. B) Some proteins are folded only by HSP-60 and do not need HSP-70 C) HSP-70 binds to proteins as they are being synthesized by the ribosome D) HSP-60 binds to proteins after they have been completely synthesized

Some proteins are folded only by HSP-60 and do not need HSP-70

Which of the following is never associated with the transport vesicle until fusion? (A) T-snare (B) Adaptor proteins (C) V-snare (D) Coat proteins

T snare

What act as protein translocators in the mitocondria

TOM complexes transfer proteins across the outer membrane and two TIM complexes transfer proteins across the inner membrane. TOM complexes are required for all nucleus encoded mitocondrial proteins into the nucleus.

Which phase in the M Phase of mitosis do the two set of daughter chromosomes arrive at the poles of the spindle and decondense. A new nuclear envelope assembles around each set marking end of mitosis.

Telophase

During what stage of the cell cycle would you expect to have the lowest amount of cellular growth and synthesis taking place? A. The S phase B. The G1 phase C. The M phase D. The G2 phase

The M phase

Apoptotic cells are efficiently phagocytosed by neighboring cells or macrophages. What does NOT normally happen in this process? A. The apoptotic cell releases some of its cytoplasmic content to induce a local inflammatory response. B. The apoptotic cell exposes phosphatidylserine at its surface, which interacts with receptor proteins on the surface of phagocytes via "bridging" proteins. C. The apoptotic cell loses or inactivates "don't eat me" signals. D. The apoptotic cell rounds up and detaches from its neighbors, which facilitates phagocytosis.

The apoptotic cell releases some of its cytoplasmic content to induce a local inflammatory response.

The antitumor drug paclitaxel promotes the assembly of microtubules and inhibits their depolymerization. What is the consequence of this effect on the cell cycle? a. The suppression of cell death b. The blockage of S-phase progression c. The arrest of cell-cycle progression at M phase d. The induction of cell-cycle progression e. The promotion of chromosome segregation in mitosis

The arrest of cell-cycle progression at M phase

The cell cycle has many checkpoints to ensure the cell is ready for division. Which of the following can occur if a cell skips cycle checkpoints. A. None of these could occur B. The cell can become cancerous C. The cell can have inhibited growth D. The cell can divide into three daughter cells instead of two E. The cell can grow in size, but never divide

The cell becomes cancerous

During G1 phase, the cell checks whether the external conditions are favorable for cell division. If the conditions are unfavorable, what happens?

The cell delays progress through G1

During G1 phase, the cell checks whether the external conditions are favorable for cell division. If the conditions are unfavorable, what happens? a. The cell enters S phase. b. The cell dies. c. The cell delays progress through G1. d. The cell continues to progress through G1.

The cell delays progress through G1.

Which of the following describes cell activity during the G1 phase of the cell cycle? A. The cell increases in size and produces new organelles B. DNA is replicated C. The cell undergoes mitosis D. The cell is in a resting phase

The cell increases in size and produces new organelles

Which morphological change is NOT typically seen in a cell that is undergoing apoptosis? A. The cell rounds up. B. The nuclear envelope disassembles. C. The cell swells and bursts. D. The nuclear chromatin breaks into fragments.

The cell swells and bursts

Which of the following is a correct statement concerning cytochrome c? A. It is an integral protein in the inner mitochondrial membrane B. The exit of this protein from the mitochondria can be a key step in programmed cell death C. It is transported from the Endoplasmic reticulum to the cyosol to activate apoptosis D. It is not present in animal cells

The exit of this protein from the mitochondria can be a key step in programmed cell death

When scientists at Johns Hopkins University fused human cells with mouse cells that had been dyed green and red respectively, they made an important breakthrough regarding cell membranes. What was it? a. Cell membranes from mice were very different than those in human cells. b. Human cell membranes did not hold the dye as well. c. The fused cells grew and reproduced pink cells. d. The proteins in the cell membranes were moving around as if in a fluid mosaic.

The fused cells grew and reproduced pink cells.

Which of the following is an accurate description of one of the many purposes of glycosylation? a. Glycosylation makes a protein more sensitive to digestion by proteases. b. Glycosylation discourages protein folding. c. Glycosylated proteins are generally more flexible. d. The glycosylation state of a protein can determine its fate along the secretory pathway.

The glycosylation state of a protein can determine its fate along the secretory pathway.

What information can be gained from in situ hybridization but not a reporter gene experiment? a. Whether or not a specific sequence is being transcribed b. The sequence of the DNA being transcribed c. The location of non-coding RNAs in a cell d. The life-span of a specific gene product e. If a protein is properly folded or not

The location of non-coding RNAs in a cell

Shruthi is studying the behaviors of motor proteins moving along cytoskeletal filaments. She uses an in vitro translation system to synthesize a motor protein that has a single molecule of green fluorescent protein (GFP) attached to its cargo-binding tail domain. She adds the GFP-tagged motor proteins to glass microscope slides containing short segments of intact microtubules and then bathes the whole preparation in an ATP-containing solution that has the same viscosity as the cytoplasm of a typical animal cell. When she observes the experiment with a fluorescence microscope, she sees the fluorescent motor proteins moving along the microtubules. What will she see if she adds an ATP-quenching enzyme, that is, an enzyme that removes all ATP, while continuing to observe the sample? a. The motor proteins will stutter (stop and start repeatedly) before coming to a halt. b. The motor proteins will glide to a gentle halt. c. The motor proteins will travel away from the microtubules along random paths. d. The motor proteins will stop and then rebound slightly as if hitting a wall. e. The motor proteins will stop dead in their tracks.

The motor proteins will stop dead in their tracks.

In order for genes to be properly expressed, many of the proteins involved in their expression need to be transported from the cytoplasm to the nucleus. Proteins targeted to the nucleus possess a "nuclear localization signal" and are transported through a specialized structure at the nuclear membrane. What is this structure called? a. The Nucleoplasm b. The nuclear pore complex c. The nucleolus d. The nuclear lamina

The nuclear pore complex

Which one of the following scenarios would allow a protein to leave the ER via its typical trafficking pathway? (A) The protein is misfolded and marked for transport to the cytosol. (B) The protein's ER exit signal is obscured by BiP. (C) The protein has not yet completed folding. (D) The protein is bound to the chaperone calnexin. (E) The protein is a fully assembled complex with all of its polypeptide subunits

The protein is a fully assembled complex with all of its polypeptide subunits

What will happen if we make mutant without ER signal sequence? A) The protein will not be translated from the mRNA B) The protein will be translated into the cytosol C) The protein will be translated into the ER but will be shorter D) The protein will be ubiquitinated and degraded in the proteosome

The protein will be translated into the cytosol

Which one of the following scenarios would allow a protein to leave the ER via its typical trafficking pathway? a. The protein's ER exit signal is obscured by BiP. b. The protein has not yet completed folding. c. The protein is misfolded and marked for transport to the cytosol. d. The protein is bound to the chaperone calnexin. e. The protein is a fully assembled complex with all of its polypeptide subunits.

The protein's ER exit signal is obscured by BiP., The protein is a fully assembled complex with all of its polypeptide subunits.

Which phase of the cell cycle involves DNA Replication?

The s phase

What are the particles tjat recogmize signals in the ER

The signal recognition particle and the signal recognition receptor. Regulate the signals that go into the rough ER

Where do vesicles leave the golgi?

The trans face whihc faces the cell membrane

Which of the following is FALSE about G-protein coupled receptor signaling? A) Receptors have 7 transmembrane domains B) Receptors interact with a trimeric G-protein complex C) The trimeric G-protein complex is on the plasma membrane D) The trimeric G-protein complex sends out cAMP

The trimeric G-protein complex sends out cAMP

5. What would happen to a cell deficient in plasma membrane T-snare proteins? (A) There would be an accumulation of transport vesicles in the cytoplasm (B) Transport vesicles would not be able to depart from the Golgi apparatus (C) Retrograde transport would be impossible (D) Nothing would happen to a cell

There would be an accumulation of transport vesicles in the cytoplasm

What would happen to a cell deficient in plasma membrane T-snare proteins? (A) There would be an accumulation of transport vesicles in the cytoplasm (B) Transport vesicles would not be able to depart from the Golgi apparatus (C) Retrograde transport would be impossible (D) Nothing would happen to a cell

There would be an accumulation of transport vesicles in the cytoplasm

What are hemidesmosomes?

These are "half desmosomes" that anchor to the basal layer of cells of the epidermis. Cell to matrix junction. composed of fibronectin, laminin, collagen. Integrins anchor it down. Intermediate filmaates such as keratin

In mammals, mitochondrial gene inheritance can be described by all of the following, except which statement? a. They are enriched in oocytes. b. They are inherited in a non-Mendelian fashion. c. They are maternally inherited. d. They are biparentally inherited e. They are cytoplasmically inherited.

They are biparentally inherited

In mammals, mitochondrial gene inheritance can be described by all of the following, except which statement? (A) They are inherited in a non-Mendelian fashion. (B) They are maternally inherited. (C) They are enriched in oocytes. (D) They are cytoplasmically inherited. (E) They are biparentally inherited

They are biparentally inherited

Which of the following is NOT correct regarding both Cas9 and EcoRI? a. They both recognize their target sequences with the help of guide RNAs b. They both create double-strand breaks in DNA c. They are both greatly useful in manipulating DNA and studying gene expression and function d. They are both part of bacterial defense mechanisms against foreign DNA e. They are both endonucleases.

They both recognize their target sequences with the help of guide RNAs

Which of the following descriptions applies to genomic DNA libraries rather than cDNA libraries? a. Different sequences are represented in them based on their transcription level. b. Their production requires use of reverse transcriptase. c. They contain intronic sequences d. They are enriched in protein-coding genes

They contain intronic sequences

Indicate whether each of the following descriptions better applies to COPI-, COPII-, clathrin-, or retromer-coated vesicles. They retrieve proteins from endosomes to the Golgi apparatus. Their coat protein forms a three-legged structure called a triskelion. They mediate transport from the ER to the cis Golgi network. They are involved in retrograde transport in the Golgi apparatus.

They retrieve proteins from endosomes to the Golgi apparatus. → Retromer-coated vesicles, Their coat protein forms a three-legged structure called a triskelion. → Clathrin-coated vesicles, They mediate transport from the ER to the cis Golgi network. → COPII-coated vesicles, They are involved in retrograde transport in the Golgi apparatus. → a. COPI-coated vesicles

What is NOT true of all cells? a. They have membrane transport proteins. b. They synthesize proteins on the ribosome. c. They replicate their genome by DNA polymerization. d. They transcribe their genetic information by RNA polymerization. e. They use RNA as a template for genomic DNA polymerization

They use RNA as a template for genomic DNA polymerization

Which of the following descriptions applies to myosin but not to kinesin and dynein motor proteins? a. They have larger structures than the other two. b. They are structurally unrelated to the other two. c. They are all minus-end directed. d. They walk on a different cytoskeletal filament than the other two e. They are generally faster than the other two.

They walk on a different cytoskeletal filament than the other two

Which of the following descriptions applies to myosin but not to kinesin and dynein motor proteins? (A) They have larger structures than the other two. (B) They walk on a different cytoskeletal filament than the other two (C) They are all minus-end directed. (D) They are generally faster than the other two. (E) They are structurally unrelated to the other two.

They walk on a different cytoskeletal filament than the other two

How are vesicles moved into the cell?

Through microtubes carried by motor proteins

How do molecules get into the nucleaus?

Through nuclear pore comples=xes that are composed of proteins called nucleoporins

How are intermediate filaments stablaized?

Through proteins such as plectin which crosslink filiaments into bundles.

What allows for vesicles to bind to the target membrane?

Through teathering proteins that recognize the rab proteins on the vesicle membrane

How are signals directed into the nucleus?

Through the nuclear localization signal whoich are composed of scaffold nucleoporins, channel nucleoporins, and a disordered region of channel nucleoporins

What is the purose of intermediate filaments?

To provide tensile strength to the cell

What is the primary function of mitogens

To stimulate cell division

Checkpoint faluire induces cell cycle arrest, preventing the cell from proceeding until it has solved the issue?

True

In gated transport, proteins and RNA molecules move between the cytosol and the nucleus through nuclear pore complexes. a. True b. False

True

In intestinal epithelial cells, the different plasma membrane domains are separated from each other by special barriers. These barriers are a result of a special structures called tight junctions in the cell surface that excludes proteins of the other domains.

True

Proteins destined for secretory vesicles for regulated secretion often aggregate in the lumen of the ER. (A) True (B) False

True

To generate cell-cell adhesion, the cadherin domain at the N-terminal tip of one cadherin molecule binds the cadherin domain at the N-terminal tip of a cadherin molecule on another cell.

True

Trimeric Fas ligands on the surface of a killer lymphocyte bind to trimeric Fas death receptors on the surface of a target cell, inducing the target cell to kill itself by undergoing apoptosis by the extrinsic pathway. True or False

True

Although lipid molecules are free to diffuse in the plane of the bilayer, they cannot flip-flop across the bilayer unless enzyme catalysts called phospholipid translocators are present in the membrane

True as Lipid bilayer is the basic structure of plasma membrane and consists of amphipathic lipid molecules. The lipid molecules do not flip flop due to the polar regions. This trnasolation of phospholipids requires an enzume to rapidly catalyxe the flip flop of one to another layer.

Which subunit combines to form microtubules? (A) Myosin (B) G-actin (C) S-actin (D) Tubulin

Tubulin

Aquaporins are protein tunnels that allow which important molecule to travel across a cell membrane? a. Calcium b. Oxygen c. Water d. Carbon Dioxide

Water

The electrons used in carbon fixation by chloroplasts ultimately come from what? a. Glyceraldehyde 3-phosphate b. Atmospheric oxygen c. Water d. Atmospheric carbon dioxide

Water

What is the kinase that inhibits Cdk activity?

Wee1

Which junction anchors actin filaments in cell to extracellular matrix?

actin-linked cell-matrix junctions

For a fully activated Cdk2 what must be in the site?

activating phosphate at threonine residue in T-loop (this changes its shape improving ability of the enzyme to bind to protein substrates)

which junction connects actin filament bundles in one cell with that in the next cell?

adherens junctions

What transmembrane adhesion protein links the cell to cell?

cadherin

Epithelial cells attach to one another through strong cell-cell adhesion mediated by?

cadherins

What type of microscope allows images to be taken in different focal planes then reconstructed into a three-dimensional image? a. Fluorescence microscope b. Confocal microscope c. Transmission electron microscope d. Light microscope

confocal

What do desmosomes do?

connects two cells together by linking their cytoskeleton. They are organized for mechanical strength, not an impermeable barrier. cadherins are proetins that span into the extracellular, made up of deesmoglien and desmoclcin, calcium dependent protiens. Desmoplakin is what ancors cadherins in cell membrane. Intermediate flimaents (keratin) hold . Good for high tensile stress

What does the cell cycle end with?

cytokinesis

Cadherins are anchored intracellularly to the?

cytoskeleton

In heart muscles what is the type of intermediate filament is bound to desmosomes?

desmin

which junction connects intermediate filaments in one cell to those in the next cell

desmosome

Particularly abundant in cells of heart muscle and the epidermis, ________ are structurally similar to adherens junctions and contain a number of homologous components. However, they are linked to intermediate filaments instead of the actin cytoskeleton

desmosomes

Mitosis in genetically identical ____ cells

diploid

Why do cells not have membrane transport proteins for O2? a. Because they need to keep the oxygen concentration low inside the reducing environment of the cell. b. Because oxygen can dissolve in water and leak in via water channels. c. Because oxygen can dissolve in the lipid bilayer and diffuse in and out rapidly without the need for a transporter. d. Because oxygen is transported in and out of the cell in special oxygencarrying proteins such as hemoglobin. e. Because oxygen transport across a membrane is energetically unfavorable.

ecause oxygen can dissolve in the lipid bilayer and diffuse in and out rapidly without the need for a transporter.

Activation of cell-surface death receptors initates the ___ ____ of apoptosis

extrinsic pathway

Which junction allows the passage of small water-soluable molecules from cell to cell

gap junctions

Meiosis is nonidentical_____ cells.

haploid

which junction anchors intermediate fillaments in cell to extracellular matrix

hemidesmosome

Cadherins generally bind to one another ______

homophilically

The major function of _____ _____ is to activate executioner caspases, which orchestrate the apoptosis program

initiator caspases

Which transmembrane adhesion protein links the attachment of a cell to the matrix

integrin

The desmoplakin after binded with plakoglobin in adhesion is attached to what intracellular filament?

intermediate filament

In epithelial cells what is the type of intermediate filament bound to desmosomes?

keratin

What is a specialized nuclear division process that produces haploid cells carrying only a single copy of each chromosome

meiosis

What occurs during vesicular transport?

membrane-enclosed transport intermediates— which may be small, spherical transport vesicles or larger, irregularly shaped organelle fragments—ferry proteins from one topologically equivalent compartment to another. The transport vesicles and fragments become loaded with a cargo of molecules derived from the lumen of one compartment as they bud and pinch off from its membrane; they discharge their cargo into a second compartment by fusing with the membrane enclosing that compartment (Figure 12-6). The transfer of soluble proteins from the ER to the Golgi apparatus, for example, occurs in this way.

What cytoskeletal element is primarily involved in cell division

microtubles

a desmosome in cell to cell adhesion is what?

nonclassical cadherin proteins

the linkage of ______ ________ to the cadherin attatches actin filaments to plasma membrane.

p120-catenin. B-catenin

The effect of the deletion of one copy of the gene encoding p53 is different from the effects caused by other p53 mutations. For example, some loss-of-function mutations in the DNA-binding domain of p53 cripple its function as a transcription regulator. Such a mutation in only one copy of the p53 gene can be enough to confer a p53 loss-of-function phenotype, even when the other copy of the gene on the homologous chromosome is wild type. Why is this the case? a.p53 is a tumor suppressor. b.p53 can induce apoptosis. c.p53 is a proto-oncogene. d.p53 forms a tetramer. e.These mutations are recessive.

p53 forms a tetramer.

Which state is the active site and cyclin when the binding of the cyclin causes the T-loop to move out of the active site, resulting in partial activation of Cdk2

partially activated

In the cytoplasm of the cell the desmosomes ends attach to?

plakoglobin

Which phase in M phase of mitosis is the breakdown of the nuclear envelope allowing chromosomes to attach to spindle microtubules via kinetochores

prometaphase

During which phase chromosome first become visible? a. interphase b. prophase c. metaphase d. telophase

prophase

The source of phosphate for a phosphorylation cascade is _____ .A) cAMP B) ATP C) protein kinase D) GTP E) protein phosphatase

protein kinase

What occurs during gated transport?

proteins and RNA molecules move between the cytosol and the nucleus through nuclear pore complexes in the nuclear envelope. The nuclear pore complexes function as selective gates that support the active transport of specific macromolecules and macromolecular assemblies between the two topologically equivalent spaces, although they also allow free diffusion of smaller molecules.

How are proteins directed to the correct cell "address".

signal sequences and sorting receptors. signal patches are sometimes used for nuclear import and in vesicular transport. SIgnal peptidases remove the signal sequence from the finished protein

What helps membraes find where the vesicles came from?

through rab proteins that are specific to where the vesicle came from

ATP synthase complex is found within the ______. A) thylakoid membrane of the chloroplast B) thylakoid space of the chloroplast 3 C) stroma of the chloroplast D) matrix of the mitochondrion E) outer membrane of the mitochondrion

thylakoid membrane of the chloroplast

Which junction seals gaps between epithelial cells

tight junctions

If myosin II heads are attached to a glass slide and actin filaments are allowed to bind to them, the filaments will glide on the surface ... A) toward their plus end in the presence of ATP. B) toward their plus end in the presence of GTP. C) toward their minus end in the presence of ATP. D) toward their minus end in the presence of GTP. E) toward their plus end in the presence of ADP

toward their minus end in the presence of ATP.

The Golgi apparatus is made up of an ordered series of compartments. To process N-linked oligosaccharides, different Golgi compartments contain different enzymes that sequentially alter the sugar chains. Which Golgi cisternae are normally responsible for the addition of galactose and NANA, respectively, to complex oligosaccharides? a. Medial cisterna; medial cisterna b. Medial cisterna; trans cisterna c. trans cisterna; trans cisterna d. cis cisterna; trans cisterna e. cis cisterna; medial cisterna

trans cisterna; trans cisterna

What occurs during protein translocation?

transmembrane protein translocators directly transport specific proteins across a membrane from the cytosol into a space that is topologically distinct. The transported protein molecule usually must unfold to snake through the translocator. The initial transport of selected proteins from the cytosol into the ER lumen or mitochondria, for example, occurs in this way. Integral membrane proteins often use the same translocators but translocate only partially across the membrane, so that the protein becomes embedded in the lipid bilayer.

0. The glycosylation state of a protein determines its fate along the secretory pathway. (A) True (B) False

true

Proteins destined for secretory vesicles for regulated secretion often aggregate in the lumen of the TGN.

true

The glycosylation state of a protein can determine its fate along the secretory pathway.

true

What are the different types of intermediate filaments?

vimentin, keratins, desmin, neurofilaments, and glial fibrillary acidic protein (GFAP)

____ is the link between the extended a-catenin and aditional actin filaments for cell to cell junction (cadherin)

vinculin

___ blood cells activate a cell-surface integrin called LFA1, which bninds to a protein called ICAM1 on the membrane of endothelial cells.

white