Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

UVA BME2104 CELL & MOLECULAR BIOLOGY FINAL EXAM WITH COMPLETE QUESTIONS & CORRECT ANSWER, Exams of Nursing

North Carolina Central University (NCCU)Nursing

UVA BME2104 CELL & MOLECULAR BIOLOGY FINAL EXAM WITH COMPLETE QUESTIONS & CORRECT ANSWERS RATED & A+ GRADED

Typology: Exams

2024/2025

Available from 07/15/2025

bleeding-spear
bleeding-spear 🇺🇸

960 documents

1 / 28

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
1 | P a g e
UVA BME2104 CELL & MOLECULAR BIOLOGY FINAL
EXAM WITH COMPLETE QUESTIONS & CORRECT
ANSWERS RATED & A+ GRADED
- made of tubulin
- intracellular transport - CORRECT ANSWER >>>Microtubules
- made of the protein called actin
- cell shape, contractility, motility - CORRECT ANSWER >>>Microfilaments
- composed of many different proteins dependent on cell type
- lend lateral strength to tissues - CORRECT ANSWER >>>Intermediate Filaments
- GTPases
- 5 possible classes (alpha, beta, gamma, delta, epsilon)
- alpha and beta exist as heterodimers
- grow as protofilaments which roll into tubes - CORRECT ANSWER >>>Tubulin
- protofilaments rolled up into groups of THIRTEEN
- 24nm diameter
- polar (beta-positive end and alpha-negative end) - CORRECT ANSWER >>>Microtubule
structure
Preferentially at the positive end, because the negative end is stabilized. - CORRECT ANSWER
>>>In microtubules, does growth occur at the + or - end and why?
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18
pf19
pf1a
pf1b
pf1c

Partial preview of the text

Download UVA BME2104 CELL & MOLECULAR BIOLOGY FINAL EXAM WITH COMPLETE QUESTIONS & CORRECT ANSWER and more Exams Nursing in PDF only on Docsity!

UVA BME2104 CELL & MOLECULAR BIOLOGY FINAL

EXAM WITH COMPLETE QUESTIONS & CORRECT

ANSWERS RATED & A+ GRADED

  • made of tubulin
  • intracellular transport - CORRECT ANSWER >>> Microtubules
  • made of the protein called actin
  • cell shape, contractility, motility - CORRECT ANSWER >>> Microfilaments
  • composed of many different proteins dependent on cell type
  • lend lateral strength to tissues - CORRECT ANSWER >>> Intermediate Filaments
  • GTPases
  • 5 possible classes (alpha, beta, gamma, delta, epsilon)
  • alpha and beta exist as heterodimers
  • grow as protofilaments which roll into tubes - CORRECT ANSWER >>> Tubulin
  • protofilaments rolled up into groups of THIRTEEN
  • 24nm diameter
  • polar (beta-positive end and alpha-negative end) - CORRECT ANSWER >>> Microtubule structure Preferentially at the positive end, because the negative end is stabilized. **- CORRECT ANSWER

** In microtubules, does growth occur at the + or - end and why?

  • 7nm in width
  • Act as ATPases
  • monodimeric unlike tubulin
  • actin is the most abundant of all intracellular proteins - CORRECT ANSWER >>> Actin structure
  • 8 - 12 nm
  • stengthening & stabilizing
  • NOT POLAR, therefore no molecular motors due to the fact that there is no cue to indicate 'directionality' - CORRECT ANSWER >>> Intermediate filaments (IF) structure
  • found in all cells, compose epithelial cells - CORRECT ANSWER >>> Keratins (IF)
  • stabilize nerve axons - CORRECT ANSWER >>> Neurofilaments (IF)
  • stabilize the nuclei of cells
  • inner side of the nuclear envelope - CORRECT ANSWER >>> Lamins (IF) No, they are symmetrical, stable, and non-polar. - CORRECT ANSWER >>> Are intermediate filaments polar?
  • a molecular motor
  • composed of 2 heavy chains each with 2 corresponding light chains
  • heavy chains wrap around each other with the heads sticking outwards **- CORRECT ANSWER

** Muscle myosin

  • infection of the gastrointestinal or central nervous system

the filament shrinks (less monomer saturation entropically) - CORRECT ANSWER >>> What happens if [m] < Kc? [m] = k(off)/k(on) - CORRECT ANSWER >>> What is the Kc formula?

  • microtubules
  • rapid increase in local monomer concentration - CORRECT ANSWER >>> Which cytoskeleton component experiences catastrophe, and what does catastrophe lead to?
  • added to the end of a growing microtubule
  • to remember: microtubules are GTPases, GTP-cap needed!
  • GTP Cap has a much lower Kc than the rest of the cell (i.e. if the cap is lost, the microtubule experiences catastrophe) - CORRECT ANSWER >>> GTP Cap
  • a few rapidly disassembling microtubules slowly feed the growth of other growing microtubles
  • often occurs at microtubule organizing centers - CORRECT ANSWER >>> Dynamic instability
  • nucleate microtubule growth
  • contain structure that 'harbor' stable (-) ends of microtubules, so positive growth extends outwards of MTOCs
  • centrosome is a MTOC - CORRECT ANSWER >>> Microtubule organizing centers (MTOCs)
  • microtubules assemble, connect to, and disassemble as part of the mitotic spindle to divide chromosomes during mitosis
  • linked to the centromere through the kinetochore - CORRECT ANSWER >>> Microtubule's role in chromosomal segregation and separation
  • drugs that prevent cell division, especially in relation to cancer cells - CORRECT ANSWER >>> Antimitotics
  • microtubules provide structure, allowing the structures to "beat" to provide cellular motion - CORRECT ANSWER >>> Microtubules in cilia and flagella
  • (+) end grows faster than the (-) end because the Kc is lower at the (+) end - CORRECT ANSWER >>> Actin polymerization
  • building on one end of the filament while the other is actively breaking down (appears to 'move,' but doesn't really) - CORRECT ANSWER >>> Actin treadmilling
  • shuttle that promotes nucleotide exchange by binding to actin monomers **- CORRECT ANSWER

** Profilin

  • monomer buffer that can shut growth down and subsequently generate large actin monomer pools - CORRECT ANSWER >>> Thymosin
  • actin-severing protein - CORRECT ANSWER >>> Gelsolin
  • allow the cell to 'crawl' by actin polymerization - CORRECT ANSWER >>> lamellipodia and pseudopodia
  • actin filament stabilizer
  • kills by stabilizing actin filaments, inhibiting disassembly
  • causes liver failure resulting in death - CORRECT ANSWER >>> Phallotoxin

time spent generating a force - CORRECT ANSWER >>> duty ratio how quickly a molecular motor uses ATP - CORRECT ANSWER >>> ATPase rate/cycle time

  • glass surface is covered with purified motor proteins
  • ATP is added, motor proteins propel the filaments across the slide
  • FILAMENTS ARE PROPELLED, NOT MOTORS - CORRECT ANSWER >>> in-vitro motility (gliding) assay in-vitro motility assay - CORRECT ANSWER >>> Actin + myosin assay microtubule gliding assay - CORRECT ANSWER >>> Kinesin or dynein + microtubule assay
  • whether or not a motor moves continuously along it's filament without "letting go" completely of the track to take a step
  • DIFFERENT THAN DNA PROCESSIVITY !!!!!!! - CORRECT ANSWER >>> Molecular motor processivity yes! - CORRECT ANSWER >>> Are kinesins and dyneins processive? only some - CORRECT ANSWER >>> Are myosins processive? Yes, ~50% efficient (in regards to energy released by hydrolysis of a single molecule)
  • more efficient than any man-made industrial motor - CORRECT ANSWER >>> Are molecular motors efficient?
  • your body never clears the virus, but doesn't experience symptoms anymore
  • occurs in herpes instances - CORRECT ANSWER >>> Latency
  • Brownian motion (thermal fluctuations) - CORRECT ANSWER >>> What drives cargo transport in molecular motors?
  • defines diffusion time in a cell of cargo
  • x^2 = NK(b)T/(3piviscosityr) - CORRECT ANSWER >>> Stokes-Einstein Equation
  • (+) end directed
  • have motor domains (heads) and cargo-binding domains (tails) - CORRECT ANSWER >>> Kinesins
  • (-) end directed
  • have motor domains (heads) and cargo-binding domains (tails)
  • can be cytoplasmic or axonemal - CORRECT ANSWER >>> Dyneins
  • cargo transport, mitosis - CORRECT ANSWER >>> Cytoplasmic dyneins
  • ciliary and flagellar motion - CORRECT ANSWER >>> Axonemal dyneins
  • motor domains
  • coiled coils
  • various cargo binding domains - CORRECT ANSWER >>> Kinesin variability
  • there isn't much, only a few types

dynein 2 (cilia/flagella cargo transport)

  • axonemal dynein (cilia/flagella movement) - CORRECT ANSWER >>> Dynein variability
  • "adaptor's adaptor"
  • facilitates dynein binding to various adaptor protein - CORRECT ANSWER >>> Dynactin
  • when a person's heart cannot pump enough blood to meet the body's oxygen requirements due to decreased cardiac contractility - CORRECT ANSWER >>> Heart failure
  • with very few exceptions, they are plus-end directed
  • have heads (motor domains) and tails that either: form filaments or bind cargo - CORRECT ANSWER >>> Myosins
  • muscle or conventional myosins (have no two tailed ends)
  • unconventional myosins (have two tail group ends) - CORRECT ANSWER >>> Myosin family "types"
  • block motor binding sites (actin)
  • make motor heads unavailable for binding (everything else) - CORRECT ANSWER >>> How do you prevent a motor from attaching to a track?
  • accomplished by allowance/inhibition of myosin binding to actin filaments
  • binding allowed in the presence of calcium - CORRECT ANSWER >>> Regulation of contraction in striated muscle
  • Troponin T, I, and C - CORRECT ANSWER >>> The troponin complex (TnT) tropomyosin binding subunit - CORRECT ANSWER >>> Troponin T (TnI) inhibitory subunit that binds to actin - CORRECT ANSWER >>> Troponin I (TnC) regulatory calcium binding subunit - CORRECT ANSWER >>> Troponin C 4 - step cycle of ATP cleavage and actin-myosin binding that ultimately results in muscle contraction - CORRECT ANSWER >>> Actin-myosin crossbridge cycle (+) end - CORRECT ANSWER >>> In the actin-myosin crossbridge cycle, what side of actin does ADP angle towards? (-) end - CORRECT ANSWER >>> In the actin-myosin crossbridge cycle, what side of actin does ADP-Pi (ADP with an additional inorganic phosphate) angle towards? (+) - CORRECT ANSWER >>> Actin filament barbed end (-) - CORRECT ANSWER >>> Actin filament pointed end
  • accomplished by phosphorylation of myosin's regulatory light chain
  • RLC regulates myosin head groups via binding and phosphorylation **- CORRECT ANSWER

** Regulation of contraction in smooth muscle

  • a kinase (catalyses transfer of phosphate from ATP to another molecule)
  • physical contact with nearby cells - CORRECT ANSWER >>> Juxtacrine

secreting factors that bind to self receptor proteins - CORRECT ANSWER >>> Autocrine

  • diffusion locally to nearby cells - CORRECT ANSWER >>> Paracrine
  • secreted factors travel through the circulatory system (bloodstream) as a means of transportation - CORRECT ANSWER >>> Endocrine
  • can activate/deactivate cascade signaling pathways by phosphate transfer - CORRECT ANSWER >>> protein kinases and phosphatases for cell signaling
  • regulated small molecules that independently transfer signals between cells
  • amplify & diffuse signals - CORRECT ANSWER >>> Second messengers
  • CCIDN (sounds like kitten!! to remember!!)
  • Ca2+ (calcium)
  • cAMP (cyclic AMP)
  • IP3 (inositol trisphosphate)
  • DAG (diacylglycerol)
  • NO (nitric oxide) - CORRECT ANSWER >>> Most common secondary messengers
  • Converts ATP to cyclic AMP in response to an extracellular signal by removal of an inorganic phosphate - CORRECT ANSWER >>> Adenylyl cyclase
  • enzyme that degrades cAMP, producing AMP, to terminate cell signaling cycles - CORRECT ANSWER >>> Phosphodiesterase

PLC (phospholipase C) cleaves phosphotidylinositol into DAG and IP3 **- CORRECT ANSWER

** Lipids as second messengers ► Ligand binding at GPCR activates a heterotrimeric G protein, which activates PLC ► PLC cleaves the phosphoinositide PIP2 to yield DAG and IP ► IP3 binds the IP3 receptor on the smooth ER to release Ca2+ into the cytosol ► Ca2+ activates MLCK, which activates myosin contraction in smooth muscle cells ► Ca2+ and DAG together activate conventional PKCs at the plasma membrane, inhibiting smooth muscle contraction ► Ca2+ is eventually pumped back into the ER ► DAG is phosphorylated by DAG kinase to yield phosphatidic acid (phospholipid precursor) - CORRECT ANSWER >>> The DAG-IP3 in the PLC/PKC pathway ► NO· is diffuses to its target ► NO· is a guanylyl cyclase (GC) agonist ► Cyclic guanosine monophosphate (cGMP) is generated ► cGMP activates protein kinase G (PKG) ► PKG phosphorylates substrates, including proteins that control cytosolic calcium concentrations, lowering [Ca2+]cytosol and inhibiting smooth muscle contraction.

  • THIS RESETS THE CYCLE: ► cGMP → GMP by phosphodiesterase 5 (PDE5) - CORRECT ANSWER >>> NO· in the guanylyl cyclase pathway

it ADP-ribosylates the alpha subunit of the g-protein (responsible for activating adenylyl cyclase)

  • the alpha subunit can no longer hydrolyze GTP - CORRECT ANSWER >>> How does cholera toxin affect G-proteins?
  • water + salt + glucose (sucrose = glucose - fructose)
  • glucose is trapped in the cells and by osmosis helps to retain intercellular H2O - CORRECT ANSWER >>> Fix for dehydration
  • mitosis and cytokinesis - CORRECT ANSWER >>> M-phase
  • S phase (DNA replication)
  • G1 and G2 - pauses/checkpoints in the cell cycle
  • G0 (extended gap where cells are quiescent, acn be permanent or temporary) - CORRECT ANSWER >>> Interphase
  • chromatin condenses into chromosomes
  • each chromosome forms sister chromatids joined in the middle at the centromere
  • centrosomes (MTOCs) initiate at the mitotic spindle - CORRECT ANSWER >>> Prophase
  • fragmentation of nuclear envelope and ER
  • centrosomes move to opposite cell ends forming the mitotic spindle & spindle poles
  • kinetochores assemble on each centromere - CORRECT ANSWER >>> Prometaphase
  • chromosomes line up in the middle of the cell on the metaphase plate **- CORRECT ANSWER

** Metaphase

  • initation and progression of a malignant cancer - CORRECT ANSWER >>> Tumorigenesis
  • formation of new blood vessels which is relevant to cancer growth and survival - CORRECT ANSWER >>> Angiogenesis
  • causing cancer - CORRECT ANSWER >>> Oncogenic
  • a gene whose product causes cancer - CORRECT ANSWER >>> Oncogene
  • a normal gene whose normal product is not cancer-causing but with a mutation will cause cancer - CORRECT ANSWER >>> Proto-oncogene
  • a gene whose product inhibits cancer - CORRECT ANSWER >>> Tumor-suppresor Gene
  • protein hormones that regulate the growth, division, and maturation of cells - CORRECT ANSWER >>> Growth factors
  • Receptor tyrosine kinases (RTKs) recognize growth factor hormones
  • RTKs bind growth factors and start a signaling cascade which includes Ras activation (a monomeric g-protein)
  • Ras passes downstream and signals downstream effectors - CORRECT ANSWER >>> Control of the G1/S transition alpha g protein in cojunction with a gamma/beta GPCR - CORRECT ANSWER >>> Trimeric Gproteins

no GPCR attached - CORRECT ANSWER >>> Monomeric G-protein

  • a monomeric G-protein
  • activated by GAP
  • inactivated by GEF - CORRECT ANSWER >>> Ras
  • MAP kinase cascade (mitogen-activated protein kinase) - CORRECT ANSWER >>> What does Ras activate?
  • serine/threonine kinases
  • translocate into the nucleus, phosphorylate transcription factors, amplify signals - CORRECT ANSWER >>> MAP kinases
  • vary cyclically in concentration
  • rise in concentration as they're transcribed and translated
  • trigger downstream evens by binding CDKs (cyclin-dependent kinases) - CORRECT ANSWER >>> Cyclins
  • Rb binds and inhibits E2F
  • E2F is required for S-phase
  • Cyclins deactivate Rb - CORRECT ANSWER >>> How do cyclins regulate G1 - S phase entry?
  • 8.5 kDa (very small)
  • signal molecule to promote degredation by ubiquitin ligases - CORRECT ANSWER >>> Ubiquitin