Bio 1: Cell Biology and Microscopy

Flashcards covering the historical development of microscopy, the parts and functions of light microscopes, and the defining tenets and scientists of Cell Theory.

Cell

The fundamental unit of life.

Hans Janssen and Zacharias Janssen

In $1590$, this father-son duo placed multiple lenses in a tube and discovered that objects seen through it appeared greatly enlarged.

Galileo Galilei

In $1609$, he invented a compound microscope using convex and concave lenses.

Giovanni Faber

In $1625$, he first used the term "microscope" to refer to the compound microscope created by Galilei.

Micrographia

The $1665$ publication by Robert Hooke in which he coined the term "cell."

Robert Hooke

An English physicist who was the first to see a plant cell under a single lens microscope in $1665$.

Antonie van Leeuwenhoek

In $1676$, he was the first to see living cells (blood cells, yeast, and insects) using his own single lens microscope.

Joseph Lister

In $1830$, he reduced spherical aberrations by using several weak lenses at specific distances to achieve high magnification without blurring.

Ernst Abbe

In $1874$, he introduced a mathematical formula correlating resolving power to light wavelength, allowing calculation of theoretical maximum resolution.

Transmission Electron Microscope (TEM)

Designed and built in $1931$ by Ernst Ruska and Max Knoll; it depends on electrons rather than light and can visualize objects as small as an atom's diameter.

Phase Contrast Illumination

Invented by Frits Zernike in $1932$, this technique allows for the imaging of transparent samples without staining.

Scanning Electron Microscope (SEM)

Invented by Ernst Ruska in $1942$, it transmits a beam of electrons across the surface of a specimen.

Confocal Imaging

A principle introduced by Marvin Minsky in $1957$ that provides higher resolution than conventional light microscopy.

CAT Scanner

Computerized Axial Tomography, developed in $1972$ by Godfrey Hounsfield and Allan Cormack for generating 3D images of internal organs.

Thomas and Christoph Cremer (1978)

developed the first practical confocal laser scanning.

Ernst Ruska (1986)

won the nobel prize for his contributions to the study of microscopy.

Scanning Tunnelling Microscope (STEM)

Invented by Gerd Binnig and Heinrich Rohrer in $1981$, it is capable of visualizing individual atoms within materials.

Douglas Prasher

The scientist who, in $1992$, cloned the green fluorescent protein used in fluorescence microscopy.

Stefan Hell (1993-1996)

pioneered the first super-resolution microscopy.

Titan 80-300 Cubed electron microscope

An electron microscope installed in Canada in $2008$ that revolutionized nanotechnology.

Researchers at UCLA University of California, Los Angeles (2010

used a cryoelectron microscope to see the atoms of a virus.

Titan Krios

A high-end transmission electron microscope developed by Thermo Fisher Scientific, officially unveiled in $2018$.

Eric Betzig, Stefan Hell, and William Moerner (2014)

got the nobel prize in chemistry for super microscopes they invented. can see smaller than 0.2

Jacques Dubochet, Joachim Frank, and Richard Henderson (2017)

created a technique for generating 3D structure of protein at an atomic level using an electron microscope.

Total Magnification Formula

$\text{Ocular lens} \times \text{Objective lens} = \text{Total magnification}$.

Resolution

The shortest distance between two points on a specimen that can still be distinguished by the observer or camera system.

Contrast

The darkness of the background with reference to the specimen.

Mechanical Parts

Movable parts of the microscope involved in providing support or strength, such as the base, arm, and stage.

Body Tube

a hollow tube through which light passes from the objective to the eyepiece.

Revolving Nosepiece

The part that holds the objectives and can be rotated to select different magnifying powers; lenses must be "clicked" into place.

Arm

connects the base and the body tube together. it serves as a handle for carrying the microscope.

Stage

the platform where the slide or specimen to be examined is placed. it has an opening at the center that allows light to pass from below the specimen.

Stage Clips

holds the slide in place.

Base

where the microscope is firmly anchored. gives support to the whole microscope

Inclination Joint

a joint found in some microscopes at which the arm is attached to the pillar of the microscope.

Mirror

reflects light from the surroundings to the specimen on the stage. it is planar on one side and concave to the other.

Condenser

concentrates the light from the light source or mirror onto the object of specimen being studied.

Iris Diaphragm

The part attached beneath the condenser that regulates the amount of light reaching the specimen.

Ocular or Eyepiece

The lens through which an observer looks; it typically has a magnification of $10x$.

Objectives

the main lenses that magnify the specimen being observed. typical objectives have magnifying power 4x, 10x, 40x, and 100x

Robert Brown

A botanist who first observed a spherical structure in plant cells in the $1820s$ and named it the "nucleus."

Theodore Schwann

A zoologist who discovered in $1839$ that animal tissues are composed of cells.

Matthias Schleiden

A botanist who concluded in $1839$ that all plant tissues are composed of cells.

Rudolf Virchow

A physician who discovered that all cells arise from preexisting cells.

Three Tenets of Cell Theory

1. Cells are the smallest unit of life. 2. Cells are the basic unit of organization. 3. Cells come only from preexisting cells.

Modern Cell Theory Additions

Cells pass on hereditary units during division and all cells are relatively similar in chemical composition and metabolic activity.

Bacterial Cell Size

$1-10\, \mu m$ (microns or micrometers) in diameter.

Typical Plant and Animal Cell Size

$10-50\, \mu m$ in diameter.

Muscle Cells

Cells provided with more mitochondria to produce the energy required for contraction.

Glandular Cells

Cells provided with more ribosomes and Golgi bodies to produce secretory materials like mucus and hormones.