BIOL 1406 General Biology I Lab Flashcards

Comprehensive vocabulary flashcards covering key topics in BIOL 1406 Lab, including the scientific method, pH/buffers, macromolecule biochemistry, cell biology/microscopy, membrane transport, and enzyme kinetics.

pH Scale

A measurement scale ranging from $0$ to $14$ that measures how acidic or basic a solution is based on its potential of hydrogen, where $7$ is neutral, below $7$ is acidic, and above $7$ is alkaline.

Acidophiles

Organisms that thrive in acidic conditions with low pH environments, such as Lactobacillus acidophilus.

Buffer

A chemical system composed of weak acids or weak bases that resists sudden changes in pH by accepting excess $H^+$ ions when solutions become too acidic or releasing $H^+$ ions when solutions become too basic.

Bicarbonate Buffer System

The primary blood buffer system in the human body where carbon dioxide ($CO_2$) reacts with water ($H_2O$) to form carbonic acid ($H_2CO_3$), which dissociates into bicarbonate ($HCO_3^-$) and hydrogen ion ($H^+$) to maintain blood pH near $7.4$.

Monosaccharide

The single monomer building block of carbohydrates, such as glucose, fructose, galactose, ribose, and deoxyribose.

Disaccharide

A carbohydrate dimer formed when two monosaccharides are joined together by a covalent glycosidic bond, such as sucrose, maltose, or lactose.

Polysaccharide

A complex carbohydrate polymer consisting of long chains of monosaccharides, including starch, glycogen, cellulose, and chitin.

Chitin

A nitrogen-containing modified monosaccharide polymer that provides structural support in arthropod exoskeletons and fungal cell walls.

Primary Protein Structure

The unique linear sequence of amino acids in a polypeptide chain linked together by covalent peptide bonds.

Secondary Protein Structure

Local repetitive coiling or folding of the polypeptide backbone into structures such as an $\alpha\text{-helix}$ or $\beta\text{-pleated sheet}$, stabilized by hydrogen bonds.

Tertiary Protein Structure

The overall three-dimensional shape of a single polypeptide chain formed by interactions among R-group side chains, including hydrogen bonds, ionic bonds, hydrophobic interactions, and covalent disulfide bridges.

Quaternary Protein Structure

The overall structural organization resulting from the assembly and interactions of two or more individual polypeptide chains.

Protein Denaturation

The process by which a protein loses its native three-dimensional structure and biological function due to environmental stressors like heat, extreme pH, or chemicals disrupting weak chemical bonds.

Amphipathic Molecule

A molecule possessing both hydrophilic (water-attracting) polar regions and hydrophobic (water-repelling) nonpolar regions, such as a phospholipid.

Phospholipid Bilayer Structures

Spontaneously assembled lipid formations in aqueous environments driven by hydrophobic interactions, taking the shape of a liposome, a micelle, or a continuous bilayer sheet.

Parfocal

The property of a microscope allowing the specimen to stay in approximate focus when switching from a lower-power objective lens to a higher-power objective lens.

Parcentered

The property of a microscope where an object centered in the field of view remains centered when switching objective lenses.

Binocular Compound Light Microscope Parts

Microscope components including: A (ocular lens), B (arm), C (resolving nosepiece), D (objective lens), E (fine adjust knob), F (coarse adjust knob), G (mechanical stage control), H (iris diaphragm lever), I (stage), and J (light source).

Nuclear Envelope

A double membrane perforated by nuclear pore complexes that encloses the eukaryotic cell nucleus and separates its contents from the cytoplasm.

Smooth Endoplasmic Reticulum

An organelle involved in lipid synthesis, carbohydrate metabolism, drug and toxin detoxification, and calcium storage.

Rough Endoplasmic Reticulum

An organelle studded with ribosomes on its outer surface that synthesizes proteins destined for membranes, cellular organelles, or secretion.

Golgi Apparatus

An organelle composed of flattened membranous sacs (cisternae) that receives vesicles at its receiving cis face, modifies products, and packages them into vesicles released at its shipping trans face.

Lysosome

A membrane-bound sac containing hydrolytic enzymes used by eukaryotic cells to digest food particles, cellular debris, or engulfed pathogens.

Central Vacuole

A large membrane-bound vacuole in plant cells enclosed by the tonoplast that stores water, nutrients, and waste products while maintaining cell turgor pressure.

Fluid Mosaic Model

The structural model describing cell membranes as a dynamic phospholipid bilayer with intercalated cholesterol and floating membrane proteins.

Osmosis

The net movement of water molecules across a selectively permeable membrane from an area of higher water concentration (lower solute concentration) to an area of lower water concentration (higher solute concentration).

Hypertonic Solution

A solution with a higher solute concentration relative to the cell's cytoplasm, causing water to move out of the cell and leading to cell shrinkage.

Hypotonic Solution

A solution with a lower solute concentration relative to the cell's cytoplasm, causing water to enter the cell and leading to cell swelling or potential lysis.

Facilitated Diffusion

Passive transport of large or polar molecules across a cell membrane down their concentration gradient via specific protein channels or carrier proteins.

Active Transport

The movement of solutes across a cell membrane against their concentration gradient, requiring cellular energy expenditure in the form of ATP.

Endocytosis Forms

Cellular uptake mechanisms including phagocytosis (engulfing solid particles/food), pinocytosis (taking in liquid droplets), and receptor-mediated endocytosis (binding specific ligands to receptors).

Activation Energy ($E_A$)

The initial investment of energy required to strain reactant bonds and reach the unstable transition state necessary for a chemical reaction to occur.

Exergonic Reaction

A spontaneous chemical reaction that releases energy, where the free energy of the products is lower than that of the reactants ($\Delta G < 0$).

Endergonic Reaction

A nonspontaneous chemical reaction that absorbs free energy from its surroundings, resulting in products with higher free energy than reactants ($\Delta G > 0$).

Effect of Enzymes on Activation Energy

Enzymes increase the rate of chemical reactions by lowering the activation energy ($E_A$) without altering the overall free energy change ($\Delta G$) of the reaction.

Active Site

The specific catalytic region of an enzyme composed of amino acid side chains where substrate molecules bind to form an enzyme-substrate complex.

Competitive Inhibitor

A substance that mimics the substrate and competes for binding directly at the active site of an enzyme, blocking substrate access.

Allosteric Inhibitor

A noncompetitive inhibitor that binds to an enzyme at an allosteric site away from the active site, inducing a conformational change that renders the active site nonfunctional.

Beer-Lambert Law

The physical law stating that the absorbance of light ($A$) by a solution is directly proportional to the solute concentration ($c$) and the path length ($l$), given by $A = \epsilon c l$.