Cell Cycle Part 2

Interphase

The phase of the cell cycle in which the cell is not actively dividing. It consists of G1, S, and G2 phases.

M-phase

The phase of the cell cycle where cell division occurs, including both mitosis and cytokinesis.

Mitosis

The process of nuclear division that results in two genetically identical daughter cells.

Prophase

The first stage of mitosis, where chromatin condenses into visible chromosomes, and the mitotic spindle begins to form.

Prometaphase

The stage in mitosis where the nuclear envelope breaks down, and the mitotic spindle attaches to the chromosomes via the kinetochores.

Anaphase

The stage of mitosis where sister chromatids are separated and pulled toward opposite spindle poles.

Telophase

The final stage of mitosis, where the nuclear envelope reforms around the separated chromatids, and the cell prepares to divide.

Cytokinesis

The division of the cytoplasm and the formation of two daughter cells, which occurs after mitosis.

Metaphase plate

The imaginary plane where chromosomes align during metaphase of mitosis.

Sister chromatids

The two identical copies of a chromosome, connected by a centromere, that are formed during DNA replication.

Kinetochore

A protein structure on the centromere of chromosomes where spindle microtubules attach during cell division.

Centromere

The region of a chromosome where the two sister chromatids are joined and where the kinetochore forms.

Spindle poles

The regions at opposite ends of the mitotic spindle that organize the microtubules during mitosis.

Kinetochore microtubules

Microtubules that extend from the spindle poles and attach to the kinetochores on chromosomes.

Polar spindle microtubules

Microtubules that extend from one spindle pole to the other, helping to push the spindle poles apart during mitosis.

Astral microtubules

Microtubules that radiate outward from the spindle poles, helping to anchor the spindle to the cell cortex.

Dynein

A motor protein that moves toward the minus end of microtubules, playing a key role in spindle dynamics and chromosome movement.

CENP-E (a kinesin)

A kinesin motor protein involved in chromosome congression and spindle attachment, playing a role in aligning chromosomes at the metaphase plate. Tail is bound to fibrous corona

MCAK (a MT depolymerase)

A motor protein that depolymerizes microtubules at their ends, playing a role in regulating spindle dynamics during mitosis.

Ndc80

A protein complex that forms part of the kinetochore, essential for attachment to microtubules during chromosome segregation.

Prometaphase congression

The movement of chromosomes toward the metaphase plate during prometaphase, facilitated by the interaction between kinetochores and spindle microtubules.

Metaphase poleward flux

State where chromosomes are seemingly static and aligned, but are undergoing a lot of dynamism

Fluorescence speckle microscopy

A technique used to study dynamic processes within living cells by tracking fluorescently labeled molecules, such as microtubules.

Chromo-kinesin

A kinesin motor protein that is associated with chromosome arms and thereby contributes to alignment

Cohesion

The process by which sister chromatids remain attached to each other through cohesin proteins, ensuring they are properly aligned and separated during mitosis.

Anaphase A

The movement of sister chromatids toward opposite spindle poles during anaphase, the MCAK at the kinetochore depolymerizes while the minus end also depolymerizes

Anaphase B

Anaphase model where the poles move away from each other, facilitated by dynein providing pulling force and kinesins providing pushing force

Contractile ring

A structure made of actin filaments that forms during cytokinesis, contracting to divide the cell into two daughter cells. Has parallel structure of actin filament and bipolar myosin filament