Cell Biology: Plasma Membrane and Nucleus

These vocabulary flashcards cover the primary structures of eukaryotic cells, including the plasma membrane, methods of transport, types of solutions, the nucleus, and the composition of DNA and chromosomes based on the lecture notes.

Cell inclusion

Dead stored substances within the cell, such as starch granules and lipid droplets.

Cytoplasm

The main water content of the cell where the exchange of material with organelles takes place and glycolysis occurs.

Glycolysis

The process of glucose breakdown that takes place in the cytoplasm.

Plasma Membrane

The outer covering of the cell made of lipids and proteins; it is a selectively permeable membrane that allows certain molecules to move in and out of the cell.

Fluid mosaic model

The structure of the plasma membrane proposed by Singer and Nicolson, described as a "Protein iceberg in a sea of lipid."

Hydrophilic head

The water-attracting portion of the lipid bilayer in the plasma membrane.

Hydrophobic tail

The water-repelling portion of the lipid bilayer in the plasma membrane.

Passive transport

Movement across the plasma membrane that requires no $ATP$ or energy usage.

Diffusion

The movement of molecules (solids, liquids, or gases) from a higher concentration to a lower concentration.

Osmosis

The movement of solvent (liquid) molecules from a higher concentration of solvent to a lower concentration of solvent through a semi-permeable membrane.

Active Transport

Movement across the plasma membrane that requires the use of $ATP$ (energy).

Exocytosis

The process of transporting material outside the cell.

Endocytosis

The process of transporting material inside the cell.

Phagocytosis

A form of endocytosis known as "cell eating."

Pinocytosis

A form of endocytosis known as "cell drinking."

Hypertonic solution

A solution containing more solute than the cell, causing the cell to shrink (plasmolysed cell).

Plasmolysis

The phenomenon where a cell shrinks due to being placed in a hypertonic solution.

Hypotonic solution

A solution containing less solute than the cell, causing the cell to swell up.

Isotonic solution

A solution with the same solute concentration as the cell, resulting in the cell size remaining the same.

Cell wall

A structure absent in animal cells that provides structural support and strength to the cell.

Cellulose

The substance that composes the plant cell wall.

Chitin

The substance that composes the fungi cell wall.

Peptidoglycan

The substance that composes the bacteria cell wall.

Nucleus

A double membrane-bounded structure discovered by Robert Brown that controls metabolic activities, cell division, and the transfer of characters from parents to offspring.

Chromatin thread

A structure made of protein and $DNA$ that condenses during cell division to form a chromosome; it acts as a heredity vehicle.

DNA (deoxyribonucleic acid)

A molecule that provides necessary information to the cell for constructing and organising itself; it contains deoxyribose sugar, a phosphate group, and nitrogenous bases.

Gene

The functional segment of $DNA$.

Nuclear pore

An opening in the nuclear envelope through which material exchange between the cytoplasm and nucleus takes place.

Nucleolus

A structure within the nucleus involved in protein synthesis.

Nitrogenous bases

The four types of bases in $DNA$: Adenine ($A$), Cytosine ($C$), Guanine ($G$), and Thymine ($T$), where $A=T$ and $G-C$.

Centromere

The region of a chromosome where sister-chromatids are joined.

Kinetochore

The site of attachment for spindle fibres on the chromosome.