Cell Cycle and Mitosis Review

Flashcards covering key concepts from the 'Introduction' and 'Cell Cycle and Mitosis' lectures, including course logistics, study strategies, lab procedures, quiz guidelines, cell cycle phases, regulatory mechanisms, and the importance of cell division.

Biology Mentorship Program

Offers workshops and study sessions led by handpicked, high-achieving, articulate, and patient mentors for biology students.

Skill Development

A component of the course designed to boost grades, requiring students to arrive on time, prepared, and follow all instructions, including specific assignment submission formats and lab safety rules.

Quiz Protocol

Quizzes are timed, must be completed in one sitting, and require students to manually hit 'Submit' before time runs out to prevent glitches; results and feedback are returned Monday/Tuesday.

Academic Consideration for Quizzes

Not offered for quizzes due to a built-in 10% grade boost given to all students at the end of the term, regardless of missed quizzes.

Cell

The fundamental unit of life; understanding its processes and environmental interactions is crucial for life sciences.

Average Adult Body Cells

Approximately 30 trillion cells, predominantly prokaryotic cells in the microbiome, with the human being a eukaryotic organism.

Cell Cycle

The series of events that take place in a cell leading to its division and duplication, including G1, S, G2, M, and G0 phases.

G1 Phase (Gap 1)

A phase in the cell cycle where the cell grows, performs normal cellular functions, differentiates if needed, and prepares for DNA synthesis (S phase).

S Phase (Synthesis)

A phase in the cell cycle where DNA is synthesized, resulting in the doubling of the cell's genome (e.g., from two copies to four copies in humans).

G2 Phase (Gap 2)

A preparatory phase in the cell cycle before mitosis, ensuring the cell is large enough and has sufficient energy, proteins, and RNA for division; cells typically do not perform normal functions during this phase.

M Phase (Mitosis)

The phase of the cell cycle dedicated to cell division, encompassing prophase, metaphase, anaphase, telophase, and cytokinesis.

G0 Phase (Quiescent Stage)

A dormant stage where cells exit the cell cycle and cease to divide or replicate, functioning in this state indefinitely (e.g., neurons) or waiting to re-enter G1.

Differentiation

The process by which a less specialized cell becomes a more specialized cell type, such as during embryogenesis when a zygote develops into various tissue cells.

Stem Cells

Cells that are quiescently sitting in G0 and have the ability to differentiate into various specialized cell types when signaled, crucial for tissue repair and regeneration.

Surface Area to Volume Ratio (SA:V)

The critical factor dictating cell size; cells divide when the volume increases faster than the surface area (cell membrane), leading to an inefficiently low ratio, to restore a high SA:V ratio necessary for efficient nutrient intake and waste removal.

Checkpoints (Cell Cycle)

Regulatory points within the cell cycle (e.g., G1-S, G2-M, mitotic spindle) that ensure proper cell growth and division, preventing uncontrolled proliferation and conditions like cancer.

Aneuploidy

A condition in which a cell has an abnormal number of chromosomes, either more or less than the typical set, often due to issues at the mitotic spindle checkpoint (e.g., Trisomy 21).

p53 (Guardian of the Genome)

A crucial transcription factor and key negative regulator (tumor suppressor protein) of the cell cycle that senses DNA damage and can initiate G1 arrest or apoptosis to prevent the replication of damaged DNA; often mutated in cancer.

DNA Damage vs. Mutation

DNA damage refers to alterations in DNA that can often be repaired by the cell, while a mutation is a permanent change in the DNA sequence that is difficult for a cell to intrinsically fix.

Tumor Suppressor Proteins

Negative regulators of the cell cycle (e.g., p53, p21, RB) that act to halt or prevent cell division under unfavorable conditions, thereby suppressing the formation of tumors.

Positive Regulators (Cell Cycle)

Molecules (e.g., cyclins and CDKs) that promote progression through the cell cycle by forming active complexes that phosphorylate target proteins, effectively giving a 'green light' for cell division.

Cyclin-CDK Complex

An active protein complex formed by a cyclin and a cyclin-dependent kinase (CDK) which, when activated (phosphorylated), phosphorylates target proteins to drive the cell cycle forward.

p21

A negative regulator protein of the cell cycle whose transcription is driven by p53; p21 inhibits cell cycle progression by binding to and inactivating the cyclin-CDK complex.

Apoptosis

Programmed cell death, a process initiated by regulators like p53 when DNA damage is irreparable, to protect the organism from potentially harmful cells.