Cell Biology and Cellular Respiration Vocabulary

A collection of vocabulary flashcards defining key cell biology concepts, organelles, cytoskeletal structures, and stages of cellular respiration based on the lecture notes.

Prokaryotic Cells

Cells that lack membrane-bounded organelles and are typically much smaller than eukaryotic cells.

Diffusion

The movement of molecules down a concentration gradient from high to low concentration in order to reach equilibrium.

Facilitated Diffusion

The passive movement of molecules from high to low concentration across a cell membrane with the aid of a protein channel.

Chloroplast

A specific organelle present only in photosynthetic cells, such as plant cells, that absorbs sunlight.

Nucleolus

A specialized region inside the nucleus responsible for synthesizing ribosomes.

Euchromatin

The loose, active form of chromatin that is readily accessible for gene transcription into messenger RNA.

Heterochromatin

The highly condensed, inactive form of chromatin that is not accessible for transcription.

Transcription

The process in the nucleus where a gene segment of DNA is copied into messenger RNA ($\text{mRNA}$).

Translation

The process at the ribosome where the sequence of messenger RNA ($\text{mRNA}$) is read to assemble amino acids into a protein.

Rough Endoplasmic Reticulum

A membrane-bounded organelle studded with ribosomes that serves as the site for protein synthesis, folding, and activation.

Smooth Endoplasmic Reticulum

A membrane-bounded organelle lacking ribosomes that synthesizes lipids, detoxifies drugs and toxins, and triggers glycogen breakdown.

Sarcoplasmic Reticulum

A specialized form of smooth endoplasmic reticulum found in muscle cells that stores calcium required for muscle contraction.

Golgi Apparatus

An organelle that receives proteins and lipids from the ER, then packages, sorts, and ships them to their proper destinations.

Lysosome

A membrane-bounded vesicle filled with digestive enzymes used to break down cellular waste, pathogens, or worn-out organelles.

Autophagy

The process by which lysosomes degrade and recycle damaged or worn-out organelles within a cell.

Autolysis

The self-destruction of an entire cell caused by lysosomes bursting and releasing digestive enzymes into the cytoplasm.

Mitochondria

The double-membraned organelle known as the powerhouse of the cell, where cellular respiration occurs and ATP is generated.

Gluconeogenesis

A metabolic pathway in the mitochondria that creates new glucose from non-carbohydrate sources like amino acids or fatty acids.

Ketogenesis

The metabolic process in mitochondria where fat is broken down to produce ketone bodies from acetyl CoA during low-sugar conditions.

Microtubules

Cytoskeletal elements involved in intracellular transport, separating chromosomes during cell division, and forming structural extensions like cilia or flagella.

Desmosomes

Cellular junctions formed by intermediate filaments that anchor adjacent cells to one another.

Hemidesmosomes

Structures formed by intermediate filaments that anchor a cell to the underlying basal membrane.

Microfilaments

Cytoskeletal structures composed of actin and myosin that function in muscle contraction, cell division pinching, diapedesis, and forming microvilli.

Diapedesis

The process by which white blood cells alter their shape using microfilaments to squeeze out of blood vessels into surrounding tissues.

Glycolysis

The initial cytoplasm-based step of cellular respiration that converts one glucose molecule into two pyruvate molecules, yielding a net of $2\,\text{ATP}$ and $2\,\text{NADH}$.

Electron Transport Chain

The final step of aerobic cellular respiration in the inner mitochondrial membrane where electron carriers drive the production of approximately $32\,\text{ATP}$.

ATP Synthase

An enzyme protein embedded in the inner mitochondrial membrane that uses proton movement driven by electron carriers to synthesize ATP.