Principles of Cell Biology Exam 2 Study Notes

Exam Instructions

The exam consists of 75 questions, each with only one correct answer.
Answers should be recorded on the provided grid sheet.
Students must enter their name and the last four digits of their Social Security number on the answer sheet.

Questions and Key Concepts

Question Breakdown

Overton's Contribution (1895)
- Identified components of the cell membrane theory through experiments using:
  - b. Lipid-soluble dyes.
Constitutively Secreted Proteins
- Characteristics:
  - d. Not immediately affected by the addition of protein synthesis inhibitors.
  - e. Release of proteins from these vesicles is often linked to ligand-receptor activation, such as insulin binding to its receptor.
Activation of Protein Kinase C
- Calcium release from:
  - b. Endoplasmic reticulum.
Transcytosis
- Describes the transport of a molecule such as a protein from one side of a cell to the other side:
  - d.
Simon and Blobel Experiment with Ohm's Law
- Focused on identifying:
  - c. Signal sequence.
Complex of 6 Proteins and RNA
- Describes:
  - d. SRP (Signal Recognition Particle).
Hydropathy Plots
- Used to examine:
  - d. Proteins, particularly their hydrophobicity/hydrophilicity.
G Protein in Receptor Tyrosine Kinase Pathway
- Commonly defective in many cancers:
  - b. Ras.
Final Destiny of LDL Receptor
- In LDL receptor-mediated endocytosis pathway:
  - a. It goes to the lysosome and is degraded.
t-SNARE and v-SNARE Function
- Critical for:
  - a. Vesicle fusion at the target membrane.
Non-G Protein Linked Receptor
- Not linked to a G protein:
  - d. Epidermal Growth Factor receptors.
Ribosomal Subunits
- 40S and 60S refer to:
  - d. Ribosomes.
Keratin Filaments Association
- Associated with:
  - a. Desmosome.
Brefeldin A Usage
- To analyze:
  - b. Anterograde (forward) movement of transitional vesicles during RER-based protein synthesis.
Organelles without DNA
- Does not contain DNA:
  - a. Peroxisomes.
Activation of Protein Kinase A
- Consequences include:
  - a. Stimulate glycogen breakdown.
  - b. Inhibit glycogen synthesis.
Milstein et al. Experiment
- Showed the presence of:
  - c. Signal sequence/signal peptidase due to reduced nascent protein residues in presence of rough microsomes.
Oligosaccharyl Transferase
- Critical in:
  - a. Glycosylation of nascent proteins.
Glycophorin
- Defined as:
  - e. An integral plasma membrane protein of erythrocytes.
Adenylyl Cyclase System
- Substrate for cAMP production:
  - c. ATP.
Mannose-6-Phosphate Addition
- Directs proteins to:
  - c. Lysosomes.
FRAP Experiment Results
- Percent of immobile proteins:
  - d. 90.
Dolichol Phosphate Role
- Associated with:
  - b. “En bloc” Glycosylation of the protein in the RER.
Kd Values Usage
- Analyzing:
  - a. Receptor ligand binding affinity and receptor/ligand number.
GMP-PNP Effect on Adenylyl Cyclase
- Consequences include:
  - e. All of the above.
Ligand-bound Receptor in cAMP System
- Binds to:
  - a. Adenylyl cyclase.
pH Differential Importance
- Functions in:
  - b. Golgi.
Rod Phototransduction Component
- Decreases cGMP:
  - e. Phosphodiesterase.
Receptor Type with Effects on Genome
- Characterized as:
  - b. Steroid receptors.
DHFR and Methotrexate Experiment
- Showed that:
  - c. Proteins must be in a folded array for translocation to occur.
Synthesis Location of Secreted Proteins
- Occurs at:
  - a. Cytoplasm/RER.
Integral Membrane Protein in RBC
- Considered a dimer:
  - d. Band 3.
NF-κB Signaling Pathway
- Activated via:
  - e. Signal-induced proteolytic cleavage of its inhibitory protein.
Danielli and Davson's Model
- Did not incorporate:
  - a. Lateral mobility of integral membrane proteins.
cAMP-dependent Protein Kinase Characteristics
- The false statement:
  - d. Can actively phosphorylate a substrate protein when the regulatory units are bound to the catalytic units.
Nitric Oxide System Components
- Includes:
  - e. All of the above.
Receptors Affecting Nuclear Transcription
- a. G protein-coupled receptors.
Amoeba Communication
- Signaling type classified as:
  - e. Paracrine.
Connexons Structure
- Associated with:
  - b. Gap junction.
Chaperone Proteins Function
- Includes:
  - e. All of the above.
Hsc70 Protein Type
- Classified as:
  - b. Chaperone.
Protein Synthesis Initiation
- Begins at:
  - b. In the cytoplasm.
Clathrin Association
- Related to:
  - e. Coated pit.
Cell Membrane Protein Characterization
- Characterized by:
  - e. All of the above.
Transporter for Glucose and Sodium
- Considered a:
  - b. Symporter.
DAG and IP3 Role
- Components of:
  - a. Protein Kinase C system.
cAMP System Component Activating Transcription
- c. cAMP-dependent protein kinase catalytic unit.
Insulin Receptor Phosphorylation
- Occurs at:
  - d. Cytoplasmic domain of the β subunit.
FRET Experiment Association
- Examined interactions between:
  - b. Receptor and G protein.
Cell Junctions Forming Fluid Barriers
- Critical junctions are:
  - c. Tight junction.
Trans Golgi Network Discovery
- Manipulated:
  - c. RER to Golgi movement of transitional vesicles.
MAP Kinase Activation
- Translocates to:
  - a. Nucleus.
KDEL Sequence Significance
- Indicates:
  - b. RER resident protein.
Cell Junction and External Calcium
- Critical for:
  - a. Neurochemical synapse.
Mitochondrial Proteins Tim23/17, Tim44, Tom40 Location
- Found at:
  - b. At the outer membrane/inner membrane "contact site".
Soluble Receptors in Cytoplasm
- Found in:
  - d. Steroid receptors.
Insulin Signaling System Classification
- Considered:
  - c. Endocrine.
Enzyme for Mitochondria and Chloroplasts
- Used to show receptor presence:
  - b. Endonucleases.
Acylation and Prenylation Functions
- Associated with:
  - a. Anchoring of plasma membrane proteins.
Mannose-6-Phosphate Address Tag Formation
- Formed in:
  - c. Cis Golgi.
Dan Branton's Freeze Fracture Technique
- Showed:
  - e. All of the above about membrane proteins.
Uses of Photoaffinity Labels
- Include:
  - e. All of the above.
Ligand-Receptor Dissociation in CURL
- Caused by:
  - a. A decrease in pH.
G Protein Activation
- Turned “on” by:
  - d. GTP.
Trans Golgi Network Function
- Primarily:
  - a. Sort proteins.
JAK Kinase Association
- Associated with:
  - b. Cytokine receptors.
Heterocaryon Definition
- Contains:
  - a. Two fused nuclei.
Oxa1 Targeting Sequence Role
- Critical for translocation in:
  - b. Mitochondria.
Serpentine Receptor Characteristics
- Spans the membrane:
  - d. 7 times.
Calcium Gradient as Second Messenger
- Approximate fold difference:
  - e. 1000 fold.
Protein Synthesis Sequence
- Chronological order:
  - a. RER – transitional vesicles – cis Golgi – medial Golgi – trans Golgi – Trans Golgi Network - secretory vesicles.
Plasmalogens Location
- Found in:
  - c. Cell membranes.
Primary Effect of Nitric Oxide Signaling
- On:
  - c. Blood pressure.
Targeting Sequence of Secretory Proteins
- Most commonly found at:
  - a. Amino end.
Cell Fusion Experiments Probes
- Used:
  - d. Antibodies.