Cell Membrane & Vesicular Transport

The cell membrane is a bilayer of phospholipids with hydrophobic tails facing inward and hydrophilic heads facing outward.

Two layers of phospholipids forming the basic structure of the cell membrane.

The nonpolar, water-fearing parts of the phospholipid, which face the interior of the membrane.

The polar, water-loving parts of the phospholipid, which face the exterior of the membrane.

The model describing the cell membrane as a fluid structure with embedded proteins.

Proteins embedded within the phospholipid bilayer.

Proteins loosely associated with the surface of the membrane.

Integral proteins that span the entire width of the cell membrane.

Lipid contributing to membrane fluidity.

A fuzzy carbohydrate-rich layer on the cell's surface, composed of carbohydrate chains linked to membrane proteins and lipids, and secreted glycoproteins/proteoglycans.

The ability of a cell to identify and interact with other cells or molecules.

The movement of molecules across a membrane without energy expenditure.

Passive transport using protein channels to help molecules move across the membrane.

Movement of molecules against a concentration gradient requiring energy expenditure.

Bulk uptake of substances into a cell, enclosing them in membrane-bound vesicles.

Bulk release of substances from a cell.

Non-selective ingestion of large particles (e.g., microorganisms, cell debris) by specialized cells (phagocytes).

Non-selective ingestion of small amounts of extracellular fluid.

Selective ingestion of specific molecules using receptors.

Cholesterol is a key component of cell membranes, influencing fluidity and protein structure.

A molecule with both hydrophilic (water-loving) and hydrophobic (water-fearing) parts.

Cholesterol slightly immobilizes cell membranes at warmer temperatures but increases fluidity at cooler temperatures by preventing tight packing of the phospholipid tails.

Cholesterol helps secure important proteins in the membrane by providing a more stable and supportive environment for proteins with specific size or shape requirements.

Areas in the plasma membrane with high concentrations of cholesterol and glycosphingolipids are thicker, enabling stable protein placement.

The ability of the cell membrane components to move around freely.

The ease with which substances can pass through a membrane.

The range of drug dosages between the minimum effective dose and the minimum toxic dose.

A reduced response to a drug after repeated use, requiring a higher dose to maintain effectiveness.

A rapid development of tolerance to a drug when doses are given in quick succession.

The loss of a drug's therapeutic effectiveness.

Complete loss of effectiveness of a drug, particularly antibiotics or anticancer drugs.

An increased response to a drug.

An abnormal or unexpected response to a drug due to genetic factors.

An immune response to a drug, resulting in allergic reactions.

A state of adapting to a drug, with withdrawal symptoms after stopping use.

The series of events that take place in a cell leading to its duplication.

The complex of DNA, RNA, and proteins that make up chromosomes.

The nuclear envelope is composed of two parallel membranes separated by a perinuclear cisterna.

Gaps in the nuclear envelope, allowing controlled passage of molecules between the nucleus and cytoplasm.

Molecules smaller than 9nm pass freely through nuclear pores, while larger ones require an energy-dependent process.

Chromatin is primarily composed of DNA wrapped around proteins called histones.

The basic structural unit of chromatin, formed by DNA wrapped around a core of histone proteins.

The nucleus isn't directly involved in protein synthesis, but it houses the DNA, which holds instructions.

Proteins needed for nucleus activity are imported from the cytoplasm.

Nuclei are often round or elongated and generally located in the centre of the cell.

Nuclei stain dark blue or black in hematoxylin and eosin-stained preparations.

The outer membrane of the nuclear envelope is continuous with the endoplasmic reticulum.

A tightly coiled and visible X chromosome in a cell; genetically inactive.

A spherical structure in the nucleus, rich in rRNA and protein.

The fluid portion of the nucleus, made of protein, and ribonucleoproteins.

Series of events that prepare a cell to divide into two.

The long period of cell growth and DNA replication in the cell cycle.

Cell growth and synthesis of macromolecules needed for DNA replication.

Phase of the cell cycle where DNA is duplicated.

Preparation for mitosis, the second gap phase.

Appears as a small granule attached to the nuclear envelope in epithelial cells or a drumstick-like appendage on the nuclei of neutrophilic leukocytes in blood smears.