Cell Biology: Structure and Function of Eukaryotic and Prokaryotic Cell Components

Vocabulary flashcards covering cellular organelles, structural components, and functional pathways from animal and plant cell biology notes.

Nucleus

The organelle of a eukaryotic cell that contains genetic material in the form of chromosomes, made up of chromatin.

Nuclear Envelope

Double membrane enclosing the nucleus; perforated by pores and continuous with the rough ER.

Nucleolus

Nonmembranous structure within the nucleus involved in the production of ribosomes.

Chromatin

Material consisting of DNA and proteins; visible in a dividing cell as individual condensed chromosomes.

Cytoplasm

The interior of prokaryotic and eukaryotic cells; in eukaryotes, it refers specifically to the region between the nucleus and plasma membrane.

Cytosol

The fluid portion within the cytoplasm in which organelles are suspended.

Rough Endoplasmic Reticulum

Part of the extensive network of membranes continuous with the nuclear envelope; contains membrane-bound ribosomes and functions in the synthesis and folding of secretable and membrane proteins.

Smooth Endoplasmic Reticulum

Part of the ER network lacking ribosomes; functions in lipid synthesis (oils, phospholipids, steroids such as testosterone), carbohydrate metabolism, drug and poison detoxification, and calcium ion storage.

Ribosomes

Complexes composed of ribosomal RNA (rRNA) that make proteins; found free-floating in the cytosol or bound to the rough ER and nuclear envelope.

Golgi Apparatus

Organelle consisting of flattened membranous sacs (cisternae) active in synthesis, modification, sorting, receiving, and shipping of cell products to intracellular or extracellular environments.

Cis face

The receiving end of the Golgi apparatus.

Trans face

The shipping end of the Golgi apparatus.

Vesicles

Membranous transport and secretory sacs responsible for carrying substances to and from the Golgi apparatus.

Lysosomes

Digestive organelles containing hydrolytic enzymes that function best in acidic environments to digest macromolecules, hydrolyze materials taken into the cell (phagocytosis), and recycle damaged organelles (autophagy).

Lytic Vacuoles

Structures present in plant cells that act like lysosomes found in animal cells.

Peroxisomes

Roughly spherical organelles with a granular or crystalline enzyme core located near mitochondria and chloroplasts; they break down alcohol, fatty acids, and amino acids, producing hydrogen peroxide as a by-product and converting it to water.

Mitochondria

Organelles with two phospholipid bilayer membranes where cellular respiration occurs and ATP is synthesized through Glycolysis, the Krebs cycle, and the Electron Transport Chain.

Cristae

Infoldings of the inner mitochondrial membrane that enclose the mitochondrial matrix.

Chloroplast

Photosynthetic organelle partitioned by two membranes that converts sunlight energy to chemical energy stored in sugar molecules using chlorophyll pigment, thylakoids, and stroma.

Thylakoids

Interconnected membranous sacs located inside the chloroplast.

Stroma

The fluid region outside the thylakoid sacs within the chloroplast.

Central Vacuole

Prominent plant organelle occupying $30\% - 90\%$ of cell volume; functions in storage, waste breakdown, macromolecule hydrolysis, and maintaining turgor pressure to keep the plant upright.

Cell Sap

The liquid solution contained inside the central vacuole of a plant cell.

Centrosome

The cell region initiating microtubules; contains a pair of centrioles and regulates cell motility and spindle fiber organization during mitosis.

Plasma Membrane

A selective phospholipid bilayer barrier containing amphipathic proteins, cholesterol, and carbohydrates that controls passage of nutrients and wastes; also known as the cell membrane.

Cell Wall

Outer protective layer that maintains cell shape; primarily composed of cellulose in plant cells and chitin in fungal cells.

Plasmodesmata

Channels passing through plant cell walls that connect the cytoplasms of adjacent cells.

Cytoskeleton

Protein network that reinforces cell shape and facilitates motility; consists of microfilaments, intermediate filaments, and microtubules.

Flagella

Motility structures found in some animal cells, composed of a cluster of microtubules enclosed within an extension of the plasma membrane.