Lecture Notes on Cell Biology

Vocabulary flashcards based on lecture notes about protein sorting, transport mechanisms, cytoskeleton, cell cycle, and cancer.

Protein Sorting

The process of sorting and distributing proteins into specific locations within a cell.

Signal Sequence

A specific sequence on a protein that directs it to a particular organelle or location within the cell.

Import Sequence

A signal sequence that facilitates the entry of a protein into an organelle.

Export Sequence

A signal sequence that facilitates the exit of a protein from an organelle.

Translocator

Small tunnels in the membrane.

Pore

A small hole.

Vesicle

Carries something around.

Nuclear Pore Complex (NPC)

A complex of proteins that forms the pore in the nuclear envelope.

Nucleoporins

Proteins that make up the nuclear pore complex.

Cytosolic Fibrils

Spine-like structures extending outwards from the nuclear pore complex, involved in tethering proteins.

Nuclear Import Receptor (NIR)

A receptor that surveys the outside of the nucleus, looking for proteins to import.

Nuclear Localization Sequence (NLS)

A specific import sequence that signals a protein to be transported into the nucleus.

Ran

A protein bound to GDP or GTP that helps facilitate the entry of the nuclear import receptor with its cargo into the nucleus.

Ran-GEF (Guanine Exchange Factor)

A protein in the nucleus that switches GDP to GTP on Ran, causing the NIR and protein of interest to separate.

Ran-GAP (GTPase Activating Protein)

A protein that converts GTP to GDP on Ran outside the nucleus.

Signal Peptidase

Enzymes that remove signal sequences.

Lumen

The space inside the ER.

Start-Stop Transfer Theory

The theory that the signal peptidase removes the first sequence (start sequence) and reveals a second one (stop sequence) that stops it in the ER Membrane.

Budding

When you make the vesicle and load cargo in it.

Fusion

When you deliver the cargo, you fuse the vesicle to a target membrane.

Cis Golgi

The ER-facing side of the Golgi.

Trans Golgi

The side where things depart the Golgi.

KDEL Sequence

A sequence that retains a protein in the ER; if a protein with this sequence ends up in the Golgi, it is sent back to the ER via a retrieval vesicle.

Cargo Receptors

Proteins that the cargo sits on.

Adapter Protein

A protein on the cargo.

Clathrin

A protein that surrounds the vesicle and is involved in the budding process and cage formation.

Clathrin-Coated Vesicle

A vesicle with clathrin wrapped around it.

Shedding/Uncoating

When the vesicle releases and sheds its coat (clathrin and adapter proteins).

VAMP

Vesicle-associated membrane protein.

Rab

Vesicle protein.

T-SNAREs

Target Snares.

Tethering Protein

A protein on the target

Cytoskeleton

Maintains the shape, protects, compartmentalizes, supports, and transports for the cell.

Intermediate Filaments

Strong, tough, sturdy rope-like protein complexes made of building blocks.

Polypeptides

Building blocks for intermediate filaments.

Lamins

Structural filaments that make up the nuclear lamina.

Keratin

Filaments found in epithelial cells; also in hair, skin, and nails.

Neurofilaments

Filaments found in nerve cells.

Nuclear Lamina

The barbed wire looking structure for the support of the nuclear envelope.

Chromatin

Plays a structural supportive role in the nucleus.

Microtubules

Primarily the highways of the cell.

Mitotic Spindles

The mitotic spindles essential in mitosis during m phase.

Cilia

Motile and non-motile structures used for cilia.

Tubulin

Building blocks for microtubules.

Dynamic Instability

The ability to build up and break down the microtubule.

MAPs

Microtubule-associated proteins.

Tau

Bridges that are stabilized by MAPs

Centrosome

Point of origin for microtubules.

Gamma Tubulin Ring Complex

Base where you extend microtubules from.

Acting Monomers

Building blocks for acting filaments.

Treadmilling

The ability to grow and shrink by adding on one side and taking off on the other

Acting-Binding protein

Aids in regulating how long or short acting filaments are.

Thymosin and Profilin

Limits the growth of actin filaments.

Formin

Protein saying yes to growth of a filament.

Lamellopodia and Filopodia

The leading edge portion on the crawling cell.

Cell Cycle

Preparation for cell division and then dividing them.

Phases of Cell Cycle

M phase and interphase

Function of G1

Growth, observing any DNA damage, pausing, and then repair.

S Phase

The phase where everything is duplicated.

Function of G2

Preparation step for the game, m phase. Growth, metabolic activity, and protein synthesis.

Checkpoints

Regulatory proteins that determine the yes or not to the stages.

Checkpoint Proteins

Cyclin and CDK.

Ubiquitination

Anaphase-promoting complex; adds the ubiquitin chain.

Wee1

Adds a phosphate to this complex.

Kinase

An enzyme adding a phosphate.

Phosphatase

An enzyme that removes a phosphate.

CDC25

Removes an inhibitory phosphate and says go.

P53

Transcription regulator

P21

Inhibitory sequence and a pause to replication.

Primary Tumor

Needs a blood vessel population.

Angiogenesis

Becomes vascularized.

Intravization

Cells detach and enter the bloodstream.

Extravization

Cells reenter a secondary sight.

Metastasis

Secondary tumor.

Carcinogens

Chemicals mutagens, rays, viruses, and select types of bacteria.

Genomic Instability

Rapid proliferation

P53 Mutated

Mutation in tumor supressor

RAS Mutated

Mutation in oncogenes

CAMs Loss

Loss of adhesion.

Malignant tumors

Sarcomas and carcinomas.

Benign Tumors

Animomas, fibromas, meningiomas.

Wnt signaling

Wnt is stimulates proliferation.

APC protein

A break for stimulation.

Growth Factor

Vascularize any rumor cell