BIOL1150/1151 Day 8: Eukaryotic Cell Organelles & Cellular Energetics

Flashcards covering Eukaryotic Cell Organelles and Cellular Energetics, including their structures, functions, and the processes of cellular respiration and fermentation.

Eukaryotic Cells

Cells characterized by the presence of internal, membrane-bound organelles and a nucleus; includes protists, fungi, plants, and animals.

Prokaryotic Cells

Cells that lack internal membrane-enclosed organelles and a nucleus; usually smaller than eukaryotic cells; includes bacteria and archaea.

Organelles

Internal cell structures, often membrane-bound, found extensively in eukaryotic cells, serving as 'little organs' to allow the cell to survive and reproduce.

Nucleus

An organelle that contains almost all of the genetic information (DNA) of the cell, surrounded by a nuclear envelope.

Nuclear Envelope

A double membrane surrounding the nucleus, allowing communication through nuclear pores.

Nucleolus

A region inside the nucleus where ribosomes are assembled from RNA and proteins (rRNA synthesis).

Endoplasmic Reticulum (ER)

An extensive network of channels connected to the plasma membrane, the nuclear envelope, and certain organelles.

Rough Endoplasmic Reticulum (RER)

A type of ER that contains ribosomes on its surface, guiding the production and folding of proteins destined for secretion or insertion into membranes; appears 'rough' due to ribosomes.

Smooth Endoplasmic Reticulum (SER)

A type of ER that lacks ribosomes; involved in lipid synthesis (e.g., phospholipids, cholesterol, steroid hormones), detoxification (biotransformation), and glucose metabolism.

Ribosomes

Sites of protein synthesis (translation); composed of rRNA and proteins, existing as free ribosomes in the cytosol or membrane-bound on the RER.

Golgi Apparatus

Consists of a series of interconnected, flattened membranous sacs where cell products are processed, modified (e.g., glycosylation, phosphorylation), and packaged into vesicles for transport.

Lysosome

Organelles containing hydrolytic enzymes (proteases, nucleases, lipases) that break down macromolecules, old organelles (autophagy), and invaders caught through endocytosis.

Mitochondria

Double-membrane organelles known as the 'powerhouses' of the cell, where cellular respiration occurs to produce ATP; characterized by an outer membrane, folded inner membrane (cristae), and a matrix, and containing their own DNA.

Cytoskeleton

A network of protein filaments that provides shape and support for the cell, composed of microtubules, intermediate filaments, and microfilaments.

Microtubules

The thickest components of the cytoskeleton, made of tubulin; involved in intracellular transport, cell division (separating chromatids), and forming cell extensions like cilia and flagella.

Intermediate Filaments

Components of the cytoskeleton that are tough, highly tensile, and tend to be more permanent; primarily function in forming cell junctions (desmosomes, hemidesmosomes) and anchoring organelles.

Microfilaments (Actin)

The thinnest components of the cytoskeleton; involved in muscle contraction (with myosin), cell division (cytokinesis), cell movement (e.g., diapedesis, phagocytosis), and forming microvilli and stereocilia.

ATP (Adenosine Triphosphate)

The high-energy molecule that serves as the primary 'fuel' for all metabolic reactions and cellular processes.

Cellular Respiration

The metabolic process that converts the chemical energy in glucose and other food molecules into ATP, occurring in phases: glycolysis, pyruvate processing, the citric acid cycle, and the electron transport chain; requires oxygen.

Fermentation

An anaerobic metabolic pathway that produces ATP through glycolysis in the absence of oxygen, by regenerating NAD+ from pyruvate.

Glycolysis

The first phase of cellular respiration, occurring in the cytoplasm, that breaks down one glucose molecule into two pyruvate molecules, producing a net of 2 ATP and 2 NADH, without requiring oxygen.

Pyruvate Processing (Transition Reaction)

The second phase of aerobic cellular respiration, occurring in the mitochondrial matrix, where two pyruvate molecules are converted into two Acetyl CoA molecules, producing 2 NADH and 2 CO2.

Citric Acid Cycle (Krebs Cycle)

The third phase of aerobic cellular respiration, occurring in the mitochondrial matrix, where Acetyl CoA is completely oxidized, producing 2 ATP, 6 NADH, 2 FADH2, and 4 CO2.

Electron Transport Chain (ETC)

The fourth and final phase of aerobic cellular respiration, occurring on the inner mitochondrial membrane, where high-energy electrons from NADH and FADH2 are passed along a series of proteins to generate a large quantity of ATP (up to 32 ATP) and water, requiring oxygen.

NADH & FADH2

Electron carrier molecules that transport high-energy electrons to the electron transport chain during cellular respiration.

Anabolic Metabolism

Metabolic pathways that build up complex biological molecules from simpler ones, requiring energy input.

Catabolic Metabolism

Metabolic pathways that break down complex biological molecules into simpler ones, releasing energy (e.g., for ATP production).