ZOO505 Handouts

Lecture 1 · Introduction to the Study · of Cell Biology · The discovery of cells

•Because of their small size, cells can only be observed with the

aid of a microscope.

•Spectacles were first made in Europe in the thirteenth century.

•The first compound (double-lens) light microscopes were constructed by the end of the sixteenth century.

•By the mid-1600s, a handful of pioneering scientists had used their handmade microscopes to uncover a world that would never have been revealed to the naked eye.

•Robert Hooke, an English microscopist discovered the cell at age 27, and he was awarded the position of curator of the Royal Society of London.

•He took a dead piece of cork and observed empty compartments in it under the microscope, and named them cell.

•Anton van Leeuwenhoek examined a drop of pond water under the microscope and he observed the crawling microscopic entities which he named as “animalcules”.

•He was also the first to describe various forms of bacteria, which he obtained from water in which pepper had been soaked and from scrapings of his teeth.

•In 1838, Matthias Schleiden, a German botanist, concluded that, plants were made of cells and that the plant embryo arose from a single cell. •In 1839, Theodor Schwann, a German zoologist and colleague of Schleiden’s, published a comprehensive report on the cellular basis of animal life.

•Schwann concluded that the cells of plants and animals are similar structures and proposed these two views of the cell theory:

1. All organisms are composed of one or more cells.
2. The cell is the structural unit of life.

(a) (b) (a)One of Robert Hooke’s more ornate compound (double-lens) microscopes.(Inset) Hooke’s drawing of a thin slice of cork, showing the honeycomb-like network of “cells.”

(b) Single-lens microscope used by Anton van Leeuwenhoek to observe bacteria and other microorganisms. The biconvex lens, which was capable of magnifying an object approximately 270 times and providing a resolution of approximately 1.35 m, was held between two metal plates.

Basic properties of cells

⚫ Cells Are Highly Complex and Organized

⚫ Cells Possess a Genetic Program and the Means to Use It

⚫ Cells Are Capable of Producing More of Themselves ⚫ Cells Acquire and Utilize Energy

⚫ Cells Carry Out a Variety of Chemical Reactions

⚫ Cells Engage in Mechanical Activities

⚫ Cells Are Able to Respond to Stimuli

⚫ Cells Are Capable of Self-Regulation

Lecture 2

Introduction to Molecular Biology

Molecular Biology

(BIO-302)

•In the broader terms, definition of molecular biology includes all aspects of the study of life from a molecular perspective.

•More precisely, the term “Molecular Biology” refers to the biology of the molecules related to genes, gene products and heredity.

•In other words, the term molecular biology is often substituted for a more appropriate term, Molecular Genetics.

•So molecular biology grew out of the disciplines of genetics and biochemistry.

•In the present age, world is in the midst of two scientific revolutions. One is information technology and the other is Molecular Biology.

•Both deal with the handling of large amounts of information.

•Molecular Biology has revolutionized the biological sciences as well especially in the fields of Health Sciences and Agricultural Sciences.