Cells

Biology of the Cell

Introduction

Ashley Davidoff MD

The Common Vein Copyright 2014

“the cell is really the ultimate morphological element in which there is any manifestation of life.”

Rudoph Virchow Cellular Pathology

Introduction

The cell is a small membrane bound structure that contains organelles and chemicals embedded in an acqeous solution with an extraordinary ability to duplicate themselves which allows them to grow.

It is the smallest living structure in biology and is the fundamental unit of life.

Parts of the Cell

Introduction

Nucleus

The nucleus is the central governing body of the cell containing all the necessary information to govern all aspects of cell structure and function.  It contains the genetic materal in the form of long strands of DNA that has recorded “recipes” for the survival of the cell.  What is the equivalent in the society? – Since it includes our past learned lessons and the way we use our past experience to ensure the survival of the cell for the future, it appears at first glance that the equivalent systems in our society includes our government and our educational systems.

The parts that make up the nucleus include the nuclear membrane, nuclear pores, nucleoskeleton, RNA molecules, nucleolus, ribosomes, all of which lie in a solution of nucleoplasm

Nucleolus (within nucleus)

The nucleolus is a conglomerate of ribosomes that is positioned in the nucleus of the cell.

Rough endoplasmic reticulum (ER)

The endoplasmic reticulum is an organelle in the cytoplasm of eukaryotuic cells that functions to synthesize proteins.

Smooth ER

The endoplasmic reticulum is an organelle in the cytoplasm of eukaryotuic cells that functions to synthesize lipids, and steroids, metabolize carbohydratesand steroids, regulate calcium concentration

Cytoskeleton

The cytoskeleton is th the scaffolding witjhin the cell that help support the cell and consists of flagella, microfilaments, (actin filaments) intermediate filaments and microtubules.

Golgi apparatus

The golgi apparatus is an organelle found in eukaryotic cells whose function is to process and package proteins before they are transported

Cytoplasm

The cytoplasm is a gel like substance is the fluid and semi fluid medium surrounding the organelles and cytoskeleton .  It also actas a fluid in which the chemicals reside.  It is the medium in which many of the reactions

Mitochondria

Vesicles

Lysosomes

Centrosome

Centrioles

Cell Membrane

Cell Theory of Life

Introduction

Biology the study of life  (A phrase coined by Jeanne Baptiste Lamark 1790)  Also George Bufon (mid 18th century)

Theories

Mechanistic View

Cartesian influenced materialistic theory

Physical and and chemical forces combine and out of them life emerges

Vitalistic View

Added to the physical and chemical forces is a vital force that provides life  Irreducible forces were part of cell

History – The Microscope

The study of the cell started with development of the microscope

Leeuwenhoek (Dutch)

Hooke (British) in the late 1600’s coined the term cell after identifying  Micrografie Cork

Malpighi (Italy)

As they pushed to higher magnification image became blurred because of chromatic aberration

Chromatic aberration – wave like character of light – different colors are brought to a different focus  So the more they tried to magnify the more it blurred.  This was solved by John Dolland (silk weaver) in 1758 who was able to correct for the aberration.  Combined two different types of glass of the lens. Euler a mathematician combined glass lens and a fluid like an oil to correct for the aberration.  Carl Zeiss used this theory 100 years later.

Robert Browne from brownian motion named the nucleus

In 1838 Matthew Schleiden put forth the universal theory of the cell being the basic building block for all plants and this was followed in 1839 by Theodore Schwann who suggested that this was the same for all animals.

References

Virchow Rudolph Cellular Pathology