Video Notes: Cell Structure, Mitosis, Cytokinesis, and Membrane Transport

Vocabulary flashcards covering cell components, mitosis/cytokinesis, and membrane transport based on the video notes.

microvillus

A tiny, finger-like projection of the cell surface that increases surface area for absorption; supported by actin microfilaments.

microfilaments

Thin, solid strands of actin in the cytoskeleton that support the cell's shape and enable movement.

desmosome

A cell junction that mechanically binds neighboring cells together, providing strong adhesion via intermediate filaments.

fat droplet

A lipid storage droplet in the cytoplasm (lipid inclusion).

ribosomes

Cell structures that synthesize proteins by translating mRNA; can be free or attached to the rough ER.

nucleus

A membrane-bound organelle that houses the cell’s DNA and coordinates activities like growth and replication.

nuclear envelope

Double lipid bilayer surrounding the nucleus with nuclear pores that regulate transport.

smooth endoplasmic reticulum

Endoplasmic reticulum lacking ribosomes; synthesizes lipids and detoxifies molecules.

hemidesmosome

A cell-matrix junction that anchors epithelial cells to the basement membrane.

plasma membrane

The phospholipid bilayer surrounding the cell that controls entry and exit of substances.

basement membrane

A thin extracellular matrix that supports epithelium and anchors it to underlying tissue.

cytokinesis

The division of the cytoplasm that completes cell division, producing two daughter cells; often overlaps late mitosis.

cleavage furrow

A contractile-ring–driven indentation of the cell membrane that begins cytokinesis, splitting the cell.

mitosis

Nuclear division that produces two genetically identical nuclei, followed by cytokinesis.

nuclear division

Another term for mitosis; division of the cell nucleus and its chromosomes.

chromosome

A condensed structure containing DNA; during mitosis it consists of two sister chromatids held at the centromere.

chromatid

One of the two identical copies of a replicated chromosome held together at the centromere.

centromere

The constricted region where sister chromatids attach; the point of attachment for spindle fibers.

anaphase

The stage of mitosis in which sister chromatids separate and move toward opposite poles.

telophase

The stage of mitosis when chromosomes arrive at the poles, begin to de-condense, and the nucleus re-forms.

diffusion

The passive spread of particles from an area of high concentration to an area of lower concentration due to random motion.

osmosis

Diffusion of water across a selectively permeable membrane from higher water concentration to lower.

selectively permeable membrane

A membrane that allows some substances to pass while blocking others, such as the plasma membrane.