Biophysics Unit 1 Study Guide Flashcards

Biophysics

The branch of science that applies principles and methods of physics to describe, quantify, and explain biological phenomena and living systems.

Steps of the Scientific Method

The ordered process of scientific inquiry: 1) Observation, 2) Problem/question statement, 3) Research, 4) Hypothesis, 5) Experimentation, 6) Analysis of results, 7) Conclusion, and 8) Communication of results.

Hierarchical Order of Living Beings

The structural levels of organization from non-living to biosphere: Atom $\rightarrow$ molecule $\rightarrow$ organelle $\rightarrow$ cell $\rightarrow$ tissue $\rightarrow$ organ $\rightarrow$ system/apparatus $\rightarrow$ organism $\rightarrow$ population $\rightarrow$ community $\rightarrow$ ecosystem $\rightarrow$ biosphere.

Pure Substance

Matter with a constant, defined chemical composition, classified either as an element (e.g., $O_2$) or a compound (e.g., $H_2O$).

Element

A pure substance composed of only one type of atom that cannot be broken down chemically (e.g., $C$, $O$, $N$, $Na$).

Compound

A pure substance consisting of two or more different chemical elements chemically combined in fixed ratios (e.g., $H_2O$, $CO_2$, $NaCl$).

Homogeneous Mixture vs. Heterogeneous Mixture

A homogeneous mixture has a uniform composition throughout (e.g., air, saline solution), whereas a heterogeneous mixture has a non-uniform composition (e.g., water and oil).

Volumetric Flask

Laboratory glassware specially designed to measure and prepare precise, exact volumes of solutions.

Density Conversion ($kg/m^3$ to $g/cm^3$)

The equivalence where $1000\,kg/m^3$ equals $1\,g/cm^3$ (derived from $1\,kg = 1000\,g$ and $1\,m^3 = 1{,}000{,}000\,cm^3$).

Hertz ($Hz$)

The SI unit of frequency, equal to one cycle per second ($s^{-1}$).

Pascal ($Pa$)

The SI unit of pressure, defined as one Newton per square meter ($Pa = \frac{N}{m^2}$).

Proton

A subatomic particle located in the nucleus with a relative charge of $+1$ and an approximate mass of $1\,u$.

Neutron

A subatomic particle located in the nucleus with a neutral charge ($0$) and an approximate mass of $1\,u$.

Electron

A subatomic particle located in the electron cloud surrounding the nucleus with a relative charge of $-1$ and an approximate mass of $\frac{1}{1836}\,u$.

Atomic Number ($Z$)

The number of protons in an atom's nucleus, which determines its element identity and equals the number of electrons in a neutral atom.

Mass Number ($A$)

The total number of protons and neutrons in an atomic nucleus ($A = Z + \text{neutrons}$).

Cation and Anion

A cation is a positively charged ion created when an atom loses electrons; an anion is a negatively charged ion created when an atom gains electrons.

Aufbau Principle

Electron configuration rule stating that electrons fill atomic orbitals in order of increasing energy, starting from the lowest available energy sublevel.

Pauli Exclusion Principle

Rule stating that a single orbital can accommodate a maximum of $2$ electrons, and they must possess opposite spins.

Hund's Rule

Rule stating that when filling degenerate orbitals of equal energy, electrons occupy each orbital singly with parallel spins before pairing up.

Valence Electrons

The electrons located in the outermost energy level of a representative element atom that participate in chemical bonding.

Primary Bioelements

The six main chemical elements that construct living matter: carbon ($C$), hydrogen ($H$), oxygen ($O$), nitrogen ($N$), phosphorus ($P$), and sulfur ($S$).

Principal Quantum Number ($n$)

Quantum number specifying the main shell or principal energy level occupied by an electron ($n = 1, 2, 3, \dots$).