Biology Final Exam Review Flashcards

A collection of vocabulary flashcards based on key concepts from the biology lecture notes.

Atomic Structure

The organization of an atom into a central nucleus containing protons (p^+) and neutrons (n^0), surrounded by electrons (e^-) occupying quantized energy levels or orbitals.

Covalent Bonds

Strong chemical bonds formed by the sharing of valence electron pairs; categorized as nonpolar (equal sharing) or polar (unequal sharing due to electronegativity differences).

Ionic Bonds

Electrostatic attractions between ions of opposite charges formed by the permanent transfer of one or more electrons from a cation to an anion.

Hydrogen Bonds

Weak intermolecular attractions between a partially positive hydrogen atom (bonded to an electronegative atom like N, O, or F) and another electronegative atom.

Polarity (Water)

A molecular property resulting from oxygen's high electronegativity (3.5) compared to hydrogen (2.1), creating a dipole with partial negative (\delta^-) and positive (\delta^+) charges.

Cohesion

The attraction between like molecules, primarily via hydrogen bonding in water, which accounts for high surface tension and the continuous water column in plants.

Adhesion

The attraction between water molecules and different polar or charged substances, such as cellulose in xylem walls, helping to counteract gravity in capillary action.

pH Scale

A logarithmic measurement (pH = -\log[H^+]) of the concentration of hydrogen ions in a solution; each unit change represents a 10-fold difference in acidity.

ATP (Adenosine Triphosphate)

The primary energy currency of the cell, composed of adenine, ribose, and three phosphate groups; energy is harvested via the hydrolysis of terminal phosphoanhydride bonds.

Prokaryotic Cells

Simple, unicellular organisms (Bacteria and Archaea) characterized by the absence of a membrane-bound nucleus, presence of circular DNA, and 70S ribosomes.

Eukaryotic Cells

Complex cells featuring compartmentalization through membrane-bound organelles, linear chromosomes within a defined nucleus, and 80S ribosomes.

Endoplasmic Reticulum (ER)

A biosynthetic network where the Rough ER (studded with ribosomes) synthesizes secretory proteins and the Smooth ER synthesizes lipids and detoxifies metabolic byproducts.

Golgi Apparatus

An organelle composed of flattened cisternae that modifies, sorts, and packages ER-derived proteins and lipids into vesicles for intracellular delivery or secretion.

Mitochondria

Double-membrane organelles that serve as the site for the Citric Acid Cycle and Oxidative Phosphorylation; they possess their own circular DNA and replicate independently.

Glycolysis

A ten-step anaerobic cytosolic pathway that catabolizes one glucose (C{6}H{12}O_{6}) into two molecules of pyruvate, yielding a net of 2 ATP and 2 NADH.

Citric Acid Cycle (Krebs Cycle)

A series of reactions in the mitochondrial matrix that oxidizes acetyl-CoA, releasing CO2 and producing 3 NADH, 1 FADH2, and 1 ATP/GTP per cycle.

Oxidative Phosphorylation

The process on the inner mitochondrial membrane where the Electron Transport Chain (ETC) creates a proton gradient to power ATP synthesis via chemiosmosis, using O_2 as the final electron acceptor.

Mitosis

A phase of the cell cycle consisting of Prophase, Metaphase, Anaphase, and Telophase, resulting in two genetically identical diploid (2n) daughter nuclei.

Meiosis

A two-stage reduction division (2n \rightarrow n) that generates four genetically unique haploid gametes through crossing over in Prophase I and independent assortment in Metaphase I.

Law of Segregation

Mendelian principle stating that the two alleles for each gene dissociate during gamete formation (Anaphase I), ensuring each gamete receives only one allele.

Law of Independent Assortment

Mendelian principle stating that different pairs of alleles segregate independently of one another during gamete formation, applicable to genes located on separate chromosomes.

Nondisjunction

A failure of homologous chromosomes or sister chromatids to separate properly during meiosis or mitosis, leading to aneuploidy in the resulting daughter cells.