Chemistry/Physics 4

Foundational Concept 4: Chemical and Physical Foundations of Biological Systems

Overview

• Complex living organisms transport materials, sense their environment, process signals, and respond to changes.

• These processes can be understood in terms of physical principles.

• The behavior of these processes follows the laws of physics, quantifiable with equations.

• Examples:

  • Electromagnetic radiation generates images or structural information about molecules.

  • Atomic structure predicts the physical and chemical properties of atoms, including ionization energy.

Content Categories

4A: Motion, Forces, Work, Energy, and Equilibrium in Living Systems

• Translation and Motion:

  • Objects can be described in terms of displacement, velocity, and acceleration.

  • Objects accelerate under external forces and are in equilibrium when net force and net torque are zero.

• Energy in Living Systems:

  • Energy required for motion originates from the metabolism of fuel molecules, governed by the same physical principles.

Topics in 4A:

• Translational Motion (PHY):

  • Units and dimensions.

  • Vectors and components.

  • Vector addition.

  • Speed and velocity (average and instantaneous).

  • Acceleration.

• Force (PHY):

  • Newton's First Law: Objects at rest will stay at rest, and objects in motion will stay in motion unless acted upon by an external force.

  • Newton's Second Law: $F = ma$ (force equals mass times acceleration).

  • Newton's Third Law: For every action, there is an equal and opposite reaction.

  • Friction: static and kinetic.

  • Center of mass.

• Equilibrium (PHY):

  • Vector analysis of forces on a point object.

  • Concept of torque and lever arms.

• Work (PHY):

  • Work done by a constant force: $W = Fd ext{ cos} heta$.

  • Mechanical advantage.

  • Work kinetic energy theorem.

• Energy of Point Object Systems (PHY):

  • Kinetic Energy: $KE = rac{1}{2}mv^2$; units of energy.

  • Potential Energy:

  • Gravitational: $PE = mgh$.

  • Spring: $PE = rac{1}{2}kx^2$.

  • Conservation of energy and power with respective units.

• Periodic Motion (PHY):

  • Concepts of amplitude, frequency, and phase.

  • Types of waves: transverse and longitudinal, wavelengths, and propagation speed.

4B: Importance of Fluids in Biological Systems

• Fluids play vital roles in blood circulation, gas exchange, and movement in lungs.

• Fluid dynamics are modeled using physical equations vital for understanding diseases related to fluids.

• Fluid Properties (PHY):

  • Density and specific gravity.

  • Buoyancy, Archimedes’ Principle.

  • Hydrostatic pressure: Pascal's Law and $P = <br>ho gh$ (pressure vs. depth).

  • Concepts of viscosity and Poiseuille’s Law.

  • Continuity equation: $A imes v = ext{constant}$.

  • Turbulence at high velocities and surface tension.

  • Bernoulli’s Equation: Relations of pressure, velocity, and height.

4C: Electrochemistry and Electrical Circuits

• Principles of charged particle movement through electric fields and their utility in energy and signal transmission.

• Biophysical aspects of ions in electrochemical gradients are vital for neuron signaling.

• Electrostatics (PHY):

  • Charge and conservation of charge, conductors vs. insulators.

  • Coulomb’s Law, electric fields, and energy considerations.

• Circuit Elements (PHY):

  • Current: $I = rac{ riangle Q}{ riangle t}$.

  • Voltage and resistance (Ohm's Law: $I = rac{V}{R}$).

  • Capacitance and its variations.

  • Magnetism (PHY):

  • Definition and properties of magnetic fields.

  • Motion of charges in magnetic fields, Lorentz force.

• Electrochemistry (GC):

  • Definitions of electrolytic cells and processes like electrolysis, anode, and cathode roles.

  • Galvanic cells, reduction potentials, and direction of electron flow.

  • Batteries: Functions and characteristics of lead-storage and nickel-cadmium batteries.

4D: Interaction of Light and Sound with Matter

• Light as electromagnetic radiation displays unique interactions based on frequency and wavelength.

• Sound is produced by oscillating pressure waves; it can be analyzed for diagnostic purposes.

• Properties of Sound (PHY):

  • Production, speed differences in different materials, intensity (decibel scale), and attenuation.

  • The Doppler Effect related to sound sources.

  • Concepts of pitch, resonance, and ultrasound applications in diagnostics.

• Properties of Light (PHY):

  • Electromagnetic radiation and behaviors including interference, diffraction, and spectroscopy.

  • Optical Elements: Reflection, refraction (Snell's law), and the phenomena associated with lenses.

• Classification of the Electromagnetic Spectrum:

  • Comprised of varied energy levels, with energy defined by $E = hf$ (Plank's equation).

4E: Atomic Structure and Behavior

• Atoms are defined by their atomic number (the number of protons) and can decay, producing various radiation forms.

• Atomic Nucleus (PHY, GC):

  • Components: protons, neutrons, isotopic variations.

  • Nuclear forces, binding characteristics, and radioactive decay types (alpha, beta, gamma).

  • Mass Spectrometry: Tools for analyzing atomic characteristics based on charge-to-mass ratios.

• Electronic Structure (PHY, GC):

  • Quantum numbers and electron energy levels (ground states, excited states).

  • Spectroscopy and principles such as the photoelectric effect.

• Periodic Table Elements (GC):

  • Groups categorized by electron structure and chemical properties.

  • Trends in ionization energy, electron affinity, and electronegativity.

• Stoichiometry (GC):

  • Molecular weight, empirical vs. molecular formulas, percent composition, the mole concept.

  • Balancing chemical reactions and understanding limiting reagents and theoretical yields.