Cell Structure and Function

These flashcards cover terminology and concepts related to cell structure and function, key for understanding cellular biology.

Nuclear Envelope

A double membrane structure surrounding the nucleus, controlling the movement of substances in and out of the nucleus.

Nuclear Lamina

A web of proteins inside the nuclear envelope that helps maintain the shape of the nucleus.

Nucleoplasm

The gel-like substance within the nucleus that contains chromatin and nucleoli.

Chromatin

The complex of DNA and proteins (histones) found in the nucleus that condenses to form chromosomes during cell division.

Histones

Proteins around which DNA is tightly coiled to form chromatin.

Ribosomes

Small structures made of RNA and protein that synthesize proteins from mRNA.

Endoplasmic Reticulum (ER)

An organelle composed of a network of membranes; involved in protein and lipid synthesis.

Rough ER

Endoplasmic reticulum with ribosomes on its surface; synthesizes and processes proteins.

Smooth ER

Endoplasmic reticulum lacking ribosomes; involved in lipid synthesis and detoxification.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Vesicular Transport

The process of moving materials within vesicles in cells.

Cisternae

Flattened membrane-bound compartments found in the Golgi apparatus and endoplasmic reticulum.

Hydrolytic Enzymes

Enzymes found in lysosomes that break down waste materials and cellular debris.

Autophagy

The process by which cells degrade and recycle their own components.

Mitochondria

Organelles known as the powerhouses of the cell; responsible for ATP production through cellular respiration.

ATP (Adenosine Triphosphate)

The main energy currency of the cell, produced in mitochondria during respiration.

Fermentation

A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen.

Prokaryotic Cells

Cells that lack a nucleus or other membrane-bound organelles, typically smaller and simpler than eukaryotic cells.

Eukaryotic Cells

Cells that contain a nucleus and membrane-bound organelles, generally larger and more complex than prokaryotic cells.

Cilia

Short, hair-like structures on the surface of some cells that aid in movement and the movement of substances.

Flagella

Long, whip-like tails found on some cells that aid in locomotion.

Macrophage

A type of immune cell that engulfs and digests foreign particles and pathogens.

Lysosomes

Organelles that contain digestive enzymes for breaking down waste materials and cellular debris.

Peroxisomes

Organelles involved in the metabolism of fatty acids and the detoxification of harmful substances.

Plasma Membrane

A phospholipid bilayer that surrounds the cell, controlling the movement of substances in and out.

Phospholipids

Molecules that make up the plasma membrane, consisting of hydrophilic heads and hydrophobic tails.

Glycoproteins

Proteins with carbohydrate chains attached, playing roles in cell recognition and signaling.

Cholesterol

A lipid that stabilizes cell membranes and influences their fluidity.

Selective Permeability

The characteristic of the plasma membrane that allows only certain substances to enter or exit the cell.

Hydrophilic

Molecules that are attracted to water, typically forming the outer layer of the plasma membrane.

Hydrophobic

Molecules that repel water, typically forming the inner layer of the plasma membrane.

Dehydration Synthesis

A chemical reaction that combines small molecules to form larger ones, with the release of water.

Hydrolysis

A chemical reaction that breaks down larger molecules into smaller ones by adding water.

Proteasomes

Protein complexes that degrade unneeded, damaged, or misfolded proteins by proteolysis.

Apoptosis

The process of programmed cell death that is necessary for maintaining health by eliminating old cells.

Nucleoli

Structures within the nucleus involved in the production of ribosomal RNA (rRNA) and ribosome assembly.

Saturated Fats

Fats whose fatty acids have all single bonds; typically solid at room temperature.

Unsaturated Fats

Fats that contain one or more double bonds in their fatty acid chains; usually liquid at room temperature.

Facilitated Diffusion

The process of transporting molecules across the plasma membrane via proteins without energy expenditure.

Active Transport

The movement of molecules against their concentration gradient, requiring energy in the form of ATP.