Cell Anatomy Vocabulary Flashcards

Vocabulary flashcards covering cell anatomy, cell membrane components, cytoplasmic organelles, cytoskeleton structure, and nuclear features based on NR-NUR101 lecture slides.

Cell

The basic structural and functional unit of all organisms, and the smallest structure that can perform all activities vital to life.

Cell Metabolism

The collective chemical reactions that occur within cells, releasing energy used for cellular activities like molecule synthesis and muscle contraction.

Cell Membrane

The outermost component of the cell that encloses the cytoplasm, acts as a selective barrier, and is composed of phospholipids, proteins, cholesterol, and carbohydrates.

Phospholipids

Lipids containing phosphorus that form a double layer (bilayer) of molecules in the cell membrane.

Cholesterol

A waxy fat carried through the bloodstream by lipoproteins that provides added strength and stability to the cell membrane by limiting phospholipid movement.

Glycolipids

Lipids with attached carbohydrates that act as surface receptors and stabilize the cell membrane, commonly found in brain cells and nerves.

Integral Proteins

Membrane proteins that float among phospholipid molecules and extend from the inner to the outer surface of the cell membrane.

Carrier Proteins

Integral membrane proteins, also known as transporters, that transport specific substances across the membrane by changing shape.

Cell Identity Marker

A glycoprotein, such as an MHC protein, that distinguishes an individual's cells from anyone else's (unless they are an identical twin).

Cytoplasm

The cellular contents located between the cell membrane and the nucleus, serving as the site of cellular activities except those occurring in the nucleus.

Cytosol

The fluid portion of the cytoplasm surrounding the organelles, constituting about $55\%$ of total cell volume.

Cytoskeleton

The internal framework of the cell consisting of protein structures (microfilaments, intermediate filaments, microtubules) that support the cell and maintain its shape.

Microfilaments

Small cytoskeletal fibrils formed from protein subunits that support the cytoplasm, provide mechanical strength, anchor to integral proteins, and participate in cell movement.

Intermediate Filaments

Cytoskeletal fibrils smaller in diameter than microtubules but larger than microfilaments that withstand tension; includes keratin in skin cells.

Keratin

A specific protein associated with skin cells that forms a type of intermediate filament.

Microtubules

The largest hollow cytoskeletal structures formed from protein subunits that assist in organelle movement, support the cytoplasm, aid in cell division, and form cilia and flagella.

Organelles

Internal structures or 'little organs' within a cell that perform specific functions.

Ribosomes

Sites of protein synthesis consisting of small and large subunits of ribosomal RNA and protein.

Free Ribosomes

Ribosomes scattered throughout the cytoplasm that synthesize proteins used within the cytosol.

Fixed Ribosomes

Ribosomes attached to the endoplasmic reticulum that synthesize proteins destined to be modified and packaged for export.

Rough Endoplasmic Reticulum

A network of folded membranes studded with ribosomes that functions to synthesize proteins embedded in the membrane.

Smooth Endoplasmic Reticulum

A network of folded membranes lacking ribosomes, involved in lipid synthesis, detoxification, and calcium regulation and storage.

Golgi Apparatus

A stack of flattened membranous sacs with secretory vesicles that collects, modifies, packages, and distributes proteins and lipids.

Secretory Vesicles

Small, membrane-bound sacs that transport and store materials produced within cells to the exterior or accumulate until released by a signal.

Lysosomes

Membrane-bound vesicles pinching off from the Golgi apparatus containing intracellular digestive enzymes to break down pathogens, worn-out structures, or damaged organelles.

Peroxisomes

Membrane-bound vesicles containing oxidase enzymes that break down fatty acids, amino acids, and hydrogen peroxide.

Mitochondria

Double-membrane organelles known as the powerhouse of the cell that carry out aerobic respiration to produce ATP.

Cristae

The inner membrane folds of a mitochondrion that enclose important metabolic enzymes.

Centrioles

Small cylindrical organelles located in the centrosome composed of 9 microtubule triplets that play an important role in chromosome movement during cell division.

Cilia

Mobile extensions of the cell surface containing specialized microtubules that move substances over the surface of the cell.

Flagella

Whiplike locomotor organelles longer than cilia that occur once per cell, such as the tail propellent of a sperm cell.

Microvilli

Minute finger-shaped projections of the cell membrane that increase cell surface area for absorption.

Proteasomes

Non-membrane-bound tunnel-like structures containing protease enzymes that degrade unneeded, damaged, or faulty proteins into small peptides.

Nucleus

The largest organelle near the center of the cell that acts as the control center for cellular operations and contains genetic material.

Nuclear Envelope

A double-membrane structure enclosing the nucleus, featuring nuclear pores where the inner and outer membranes join.

Chromatin

The loosely coiled form of DNA and proteins present during most of a cell's life before coiling into distinct chromosomes for cell division.