Module 3: The Plasma Membrane and Mitochondria

These flashcards cover key concepts related to the plasma membrane and mitochondria, including definitions of important terms, processes, and structures essential for understanding cellular metabolism and membrane dynamics.

Phospholipid Bilayer

A double layered sheet formed by phospholipids that is semi-permeable, allowing certain molecules to enter or exit the cell.

Hydrophobic

Molecules that do not interact with water and can pass freely across the plasma membrane.

Glycerol

A three-carbon chain with three hydroxyl groups that acts as the backbone of phospholipids.

Cholesterol

A major component in animal plasma membranes that affects membrane fluidity.

Micelles

Droplets formed by phospholipids with fatty acid tails oriented inward, surrounded by polar water.

Aquaporins

Specific channel proteins that facilitate the rapid transport of water across the plasma membrane.

Tonicity

The measure of osmotic pressure that describes the relative concentrations of solutes on either side of the cell membrane.

Hypertonicity

A condition where the concentration of solutes is higher outside the cell, causing water to flow out and cell shrinkage.

Fluid-Mosaic Model

A model that describes the plasma membrane as a dynamic structure where lipids and proteins move laterally within the layer.

Catabolism

The metabolic process that breaks down macromolecules to release energy.

Anabolism

The metabolic process that builds macromolecules and requires energy input.

ATP

Adenosine triphosphate; the primary energy carrier in cells.

NAD+

Nicotinamide adenine dinucleotide; a coenzyme that can be reduced to NADH by gaining electrons.

Glycolysis

The metabolic process that breaks down glucose into pyruvate, generating ATP and high-energy electron carriers.

Lipid Raft

A cluster of membrane proteins, phospholipids, and other constituents in the membrane that interact with each other.

Flippases

Transport proteins that move specific phospholipids between the leaflets of the bilayer.

Carrier Proteins

Proteins that undergo conformational changes to transport molecules across the membrane.

Active Transport

The movement of molecules across a membrane against their concentration gradient, requiring energy.

Krebs Cycle

A series of biochemical reactions that convert acetyl-CoA into CO2 and H2O, generating ATP and electron carriers.

FAD

Flavin adenine dinucleotide; a coenzyme that can be reduced to FADH2 during metabolic reactions.

Phospholipid Bilayer

A double layered sheet formed by phospholipids that is semi-permeable, allowing certain molecules to enter or exit the cell.

Hydrophobic

Molecules that do not interact with water and can pass freely across the plasma membrane.

Glycerol

A three-carbon chain with three hydroxyl groups that acts as the backbone of phospholipids.

Cholesterol

A major component in animal plasma membranes that affects membrane fluidity.

Micelles

Droplets formed by phospholipids with fatty acid tails oriented inward, surrounded by polar water.

Aquaporins

Specific channel proteins that facilitate the rapid transport of water across the plasma membrane.

Tonicity

The measure of osmotic pressure that describes the relative concentrations of solutes on either side of the cell membrane.

Hypertonicity

A condition where the concentration of solutes is higher outside the cell, causing water to flow out and cell shrinkage.

Fluid-Mosaic Model

A model that describes the plasma membrane as a dynamic structure where lipids and proteins move laterally within the layer.

Catabolism

The metabolic process that breaks down macromolecules to release energy.

Anabolism

The metabolic process that builds macromolecules and requires energy input.

ATP

Adenosine triphosphate; the primary energy carrier in cells.

NAD+

Nicotinamide adenine dinucleotide; a coenzyme that can be reduced to NADH by gaining electrons.

Glycolysis

The metabolic process that breaks down glucose into pyruvate, generating ATP and high-energy electron carriers.

Lipid Raft

A cluster of membrane proteins, phospholipids, and other constituents in the membrane that interact with each other.

Flippases

Transport proteins that move specific phospholipids between the leaflets of the bilayer.

Carrier Proteins

Proteins that undergo conformational changes to transport molecules across the membrane.

Active Transport

The movement of molecules across a membrane against their concentration gradient, requiring energy.

Krebs Cycle

A series of biochemical reactions that convert acetyl-CoA into CO2 and H2O, generating ATP and electron carriers.

FAD

Flavin adenine dinucleotide; a coenzyme that can be reduced to FADH2 during metabolic reactions.

Oxidative Phosphorylation

The process by which ATP is formed as a result of the transfer of electrons from NADH and FADH2 to O_2 by a series of electron carriers.

Electron Transport Chain (ETC)

A series of protein complexes and other molecules embedded in the inner mitochondrial membrane that transfer electrons from electron donors to electron acceptors via redox reactions, pumping protons across the membrane.

Chemiosmosis

The movement of ions across a selectively permeable membrane, down their electrochemical gradient, used to generate ATP by harnessing the energy of a proton gradient.

ATP Synthase

An enzyme complex in the inner mitochondrial membrane that uses the energy of a proton gradient to synthesize ATP from ADP and inorganic phosphate.

Proton-motive force

The potential energy stored in a proton gradient across the inner mitochondrial membrane, driving ATP synthesis via chemiosmosis.

Final Electron Acceptor in ETC

Oxygen (O2); it accepts electrons at the end of the electron transport chain, forming water (H2O).