MCB 150: The Molecular and Cellular Basis of Life - Mutations and Cellular Processes

A comprehensive collection of vocabulary flashcards based on key concepts from MCB 150 lecture notes, focused on mutations, cell processes, and cellular structures.

Same Sense Mutation

A mutation where a nucleotide is changed to a different codon that specifies the same amino acid, resulting in no effect on protein product or function.

Nonsense Mutation

A mutation that causes a codon specifying an amino acid to change to a stop codon, resulting in premature termination of protein synthesis.

Missense Mutation

A type of mutation where a codon specifying an amino acid is changed to a codon for a different amino acid, which can alter protein functionality.

Sickle-Cell Anemia

A genetic disorder characterized by a defect in the β-globin subunit of hemoglobin, leading to distorted red blood cells that cause pain and anemia.

Phenylketonuria (PKU)

An inherited disorder resulting from a mutation that affects the metabolism of phenylalanine, leading to mental impairment; can be managed with a special diet.

Frameshift Mutation

A mutation caused by the addition or removal of bases that disrupts the normal reading frame of the mRNA, usually resulting in premature termination of protein synthesis.

Codon Table

A table that shows the correspondence between nucleotide sequences in mRNA and the amino acids they specify, allowing for prediction of amino acid changes due to mutations.

In-Frame Mutation

A mutation involving the loss or addition of nucleotides in groups of three, which does not shift the reading frame and only alters one amino acid in the protein.

Cystic Fibrosis

A genetic disorder that results from mutations in the CFTR gene, leading to defective protein function and accumulation of salt in cells.

Chromosomal-level Mutation

Mutations that affect the structure of chromosomes, such as translocations, duplications, or deletions, which can lead to various disorders.

Ames Test

A test used to assess the mutagenicity of compounds by observing their ability to induce mutations in a specific strain of bacteria.

Dynamic Instability

The phenomenon where microtubules undergo rapid cycles of assembly and disassembly, crucial for their function in cellular processes.

Microtubule-Organizing Center (MTOC)

A cellular structure that organizes the microtubules, with the centrosome being the major MTOC in animal cells.

Kinesin

A motor protein that moves along microtubules and transports cellular cargo, using energy from ATP.

Dynein

A motor protein that transports cargo toward the minus end of microtubules, involved in various cellular processes including vesicle transport.

Transcription

The process by which a segment of DNA is copied into RNA by the enzyme RNA polymerase.

Translation

The process by which ribosomes synthesize proteins using mRNA as a template.

Nuclear Localization Signal (NLS)

A sequence of amino acids that directs the transport of a protein into the nucleus.

Nuclear Export Signal (NES)

A sequence of amino acids that directs the transport of a protein out of the nucleus.

Endoplasmic Reticulum (ER)

An organelle involved in protein and lipid synthesis, consisting of a network of membranes.

G-Protein Coupled Receptor (GPCR)

A large family of membrane receptors that play a role in transmitting signals from outside to inside the cell.

Ligand

A molecule that binds specifically to a receptor, triggering a response in the cell.

Caspase Cascade

A series of enzymatic reactions triggered during apoptosis that lead to programmed cell death.

Apoptosis

The process of programmed cell death that eliminates damaged or unwanted cells in an organized manner.

cAMP (cyclic Adenosine Monophosphate)

A secondary messenger important in many biological processes, including the signaling pathway activated by GPCRs.

Adenylyl Cyclase

An enzyme that converts ATP to cyclic AMP (cAMP) in response to extracellular signals.

Phosphodiesterase

An enzyme that breaks down cAMP, thus terminating the signaling pathway.

Epinephrine Pathway

A signaling cascade initiated by the binding of epinephrine to its receptor, leading to various physiological responses.

RNA interference

A biological process where RNA molecules inhibit gene expression or translation, through the targeting of mRNA.

Non-Coding RNA (ncRNA)

RNA molecules that do not encode proteins but have roles in regulating gene expression and other cellular processes.

Signal Transduction

The process by which a cell responds to external signals, resulting in a change in cellular activity.

Cell Communication Types

Various methods by which cells communicate, including direct contact, secreted signals, and receptor-ligand interactions.

Mitotic Spindle

A structure composed of microtubules that segregates chromosomes during cell division.

Centrosome

A cellular structure that serves as the main organizing center for microtubules in the cell.

M-phase

The phase of the cell cycle that includes mitosis and cytokinesis.

Interphase

The phase of the cell cycle when the cell is not dividing, consisting of G1, S, and G2 phases.

Prophase

The first stage of mitosis where chromosomes condense and the mitotic spindle begins to form.

Cytokinesis

The process of dividing the cytoplasm of a parental cell into two daughter cells.

Microfilaments

Thin protein filaments made of actin, involved in various cellular activities including movement and maintenance of cell shape.

Cilia and Flagella

Hair-like structures that extend from the surface of cells and are involved in cell movement or movement of fluids.

Chromatid

One of the two identical halves of a duplicated chromosome, which are separated during mitosis.

Centriole

A cylindrical organelle involved in cell division, helping to organize the mitotic spindle.

RNA Polymerase

An enzyme that synthesizes RNA from a DNA template during transcription.

Signal Amplification

The process through which a single signaling molecule can produce a large response due to sequential activation of downstream signaling components.

Cell Cycle Checkpoints

Regulatory points in the cell cycle that ensure proper division and function before proceeding to the next phase.

Cancer

A disease characterized by uncontrolled cell division, often caused by mutations that affect cell cycle regulation.

Telophase

The final stage of mitosis where chromosomes decondense and the nuclear envelope re-forms around each set of chromosomes.

Metaphase

The stage of mitosis where chromosomes line up along the metaphase plate before being separated.

Anaphase

The phase of mitosis where sister chromatids are pulled apart to opposite poles of the cell.

Prometaphase

The stage of mitosis where the nuclear envelope breaks down and microtubules attach to chromosomes.

Prokaryotic Cell Division

The process where bacteria replicate their DNA and divide in a simpler manner than eukaryotic cells.

Eukaryotic Cell Division

A complex process that involves mitosis and cytokinesis, with multiple phases and checkpoints.

Cellular Respiration

The metabolic processes that convert nutrients into energy (ATP), involving glycolysis and oxidative phosphorylation.

Transcription Factors

Proteins that help regulate the transcription of specific genes by binding to nearby DNA.

Epigenetics

The study of heritable changes in gene expression that do not involve changes to the underlying DNA sequence.

Gene Regulation

The process of turning genes on and off, affecting how genes are expressed and the resulting traits.

Oncogenes

Genes that have the potential to cause cancer when mutated or expressed at high levels.

Tumor Suppressor Genes

Genes that help prevent uncontrolled cell growth; mutations can lead to cancer.

Dihybrid Cross

A genetic cross that considers two traits, typically to observe the probability of offspring genotypes.

Cytoskeleton

A dynamic network of protein fibers that provide structure and shape to the cell, as well as facilitating cell movement.

Microvilli

Small, finger-like projections on the surface of cells that increase surface area for absorption.

Actin Filaments

Polymers of actin that play crucial roles in cell shape, motility, and division.

G-actin

Globular form of actin that can polymerize to form filamentous actin (F-actin).

F-actin

Filamentous form of actin that forms part of the cytoskeleton.

Cell Growth

The increase in cell size and mass, often occurring during interphase before cell division.

DNA Replication

The process by which a cell copies its DNA before cell division.

Mitosis

The process of division of a cell's replicated DNA into two identical daughter cells.

Interphase Sub-phases

The stages of interphase: G1 (growth), S (synthesis), and G2 (preparation for mitosis).

Cellular Differentiation

The process by which a cell changes from one cell type to another, often to fulfill a specific function.

Molecular Motors

Proteins that convert chemical energy into mechanical work by moving across cytoskeletal filaments.

Vesicle Transport

The movement of vesicles within a cell, often facilitated by motor proteins like kinesin and dynein.

Split Genes

Genes comprised of exons (coding regions) and introns (non-coding regions) that undergo splicing during mRNA processing.

Post-Translational Modifications

Chemical modifications that occur after protein synthesis, influencing the protein's function and activity.

Signal Transduction Pathway

A sequence of molecular events and chemical reactions that lead to a cellular response following the binding of a ligand to its receptor.

Cell Cycle Control System

A complex network of signaling pathways that regulate the progression of the cell cycle and ensure proper cell division.

S phase

The phase of the cell cycle where DNA replication occurs, resulting in the doubling of genetic material.

Protein Chaperones

Proteins that assist in the proper folding and assembly of other proteins.

Cellular Metabolism

The sum of all chemical reactions that occur within cells to maintain life.

Glycolysis

The metabolic pathway that breaks down glucose into pyruvate, yielding ATP.

Oxidative Phosphorylation

The process by which ATP is produced in the mitochondria through electron transport and chemiosmosis.

Microtubules

Cylindrical structures composed of tubulin, playing key roles in cell shape, transport, and division.

Signal Reception

The first step in a cell signaling process, where a signaling molecule binds to a receptor.

Chemical Gradient

A difference in concentration of a substance across a distance, driving diffusion and transport processes.

Clathrin-coated vesicles

Vesicles involved in the transport of molecules within cells, formed by the protein clathrin.

Secondary Messengers

Small molecules that relay signals from receptors to target molecules inside cells.

Nuclear Envelope

A double membrane that encloses the nucleus, separating it from the cytoplasm.

Gene expression

The process by which information from a gene is used to synthesize a functional gene product, usually a protein.

Apoptotic Signals

Signals that initiate the programmed cell death process, ensuring proper tissue homeostasis.

Cytoplasmic Division

The final stage of cell division, where the cytoplasm is split between the two daughter cells.

Mitochondrial Membrane

A double membrane surrounding the mitochondria, essential for ATP production and metabolic functions.