Fall Midterm Learning Mastery Flashcards

Vocabulary practice flashcards based on the Fall Midterm Learning Mastery objectives covering molecular interactions, macromolecules, cell structures, membranes, and enzyme kinetics.

Hydrogen Bond

A non-covalent attractive interaction between polar regions of molecules, represented by dotted lines in molecular diagrams.

Cellulose

A structural polysaccharide found in plant cell walls, composed of linked glucose units.

Starch

A polysaccharide used by plants for long-term energy storage.

Glycogen

An extensively branched polysaccharide used for energy storage in humans and animals.

Dehydration Synthesis

A chemical reaction in which two monomers are covalently linked together with the simultaneous removal of a water molecule.

Hydrolysis

A chemical reaction that cleaves covalent bonds in polymers into monomers through the addition of a water molecule.

Monosaccharide

The simplest form of carbohydrate, consisting of a single sugar monomer that serves as a building block for complex carbohydrates.

Disaccharide

A carbohydrate composed of two monosaccharide units joined together by a covalent bond.

Polysaccharide

A carbohydrate polymer composed of many monosaccharide units linked together, functioning in storage or structure.

Triglyceride

A lipid molecule constructed from a single glycerol molecule attached to three fatty acid chains via ester linkages.

Ester Linkage

The covalent bond formed between the hydroxyl group of glycerol and the carboxyl group of a fatty acid in lipids.

Phosphodiester Bond

The covalent linkage that joins successive nucleotides along a polymer of DNA or RNA, connecting the 3' carbon of one sugar to the 5' carbon of the next.

Nucleoside

A molecular component of nucleic acids composed solely of a nitrogenous base attached to a pentose sugar, lacking a phosphate group.

Nucleotide

The basic monomer of nucleic acids, consisting of a nitrogenous base, a pentose sugar, and one or more phosphate groups.

5' and 3' Directionality

The structural polarity of a nucleic acid strand, designated by the free 5' carbon (often attached to a phosphate group) at one end and the free 3' carbon (hydroxyl group) at the opposite end.

Peptide Bond

The covalent chemical bond linking two consecutive amino acids, formed between the carboxyl carbon of one amino acid and the amino nitrogen of another.

N-terminus and C-terminus

The two opposite ends of a polypeptide chain, defined respectively by a free amino group (N-end) and a free carboxyl group (C-end).

R Group

The variable chemical side chain attached to the central alpha-carbon of an amino acid that determines its unique chemical and physical properties.

Prokaryotic Cell

A type of cell lacking a membrane-bound nucleus and internal membrane-bound organelles.

Eukaryotic Cell

A cell that possesses a distinct, membrane-enclosed nucleus and compartmentalized membrane-bound organelles.

Membrane Fluidity

The property of the lipid bilayer that allows lipids and embedded proteins to diffuse and move laterally within the cell membrane.

Osmosis

The passive net movement of water molecules across a selectively permeable membrane toward a region of higher solute concentration.

Aquaporin

A specialized membrane channel protein that facilitates the rapid, selective passage of water molecules across cell membranes.

Water-Soluble Hormone

A hydrophilic signaling molecule that cannot readily pass through the plasma membrane and instead binds to receptors situated on the cell surface.

Lipid-Soluble Hormone

A hydrophobic signaling molecule capable of diffusing directly across the cell membrane to bind to intracellular receptors.

Potential Energy

Stored energy in biological systems, such as the chemical energy held within molecular bonds or electrochemical gradients.

Kinetic Energy

The energy of motion in biological systems, which is coupled to cellular work and molecular collisions.

Gibbs Free Energy

A thermodynamic measure of the usable energy in a biological system that determines the spontaneity and direction of a chemical reaction.

Exergonic Reaction

A spontaneous chemical reaction that releases energy, characterized by a negative change in Gibbs Free Energy ($\Delta G < 0$).

Endergonic Reaction

A non-spontaneous chemical reaction that requires an input of free energy, characterized by a positive change in Gibbs Free Energy ($\Delta G > 0$).

Transition State

The unstable, high-energy intermediate molecular configuration reached during a chemical reaction as reactant bonds break and product bonds form.

Active Site

The specific region of an enzyme containing unique amino acid side chains where substrate molecules bind and undergo catalysis.

Activation Energy

The minimum amount of initial energy required to initiate a chemical reaction, which enzymes lower to accelerate reaction rates.

Competitive Inhibition

A form of enzyme regulation in which an inhibitor structurally resembles the substrate and competes directly for binding at the active site.

Non-Competitive Inhibition

A form of enzyme regulation where an inhibitor binds to a separate site away from the active site, altering the enzyme's conformation and catalytic function.

Energy-Coupled Reaction

A biological process wherein an energetically favorable, exergonic reaction drives an energetically unfavorable, endergonic reaction.