May-12-2015
Bio-2600
Introduction to Cell Biology
Textbook (required)
Essential Cell Biology
FOURTH EDITION
Alberts • Bray • Hopkin • Johnson • Lewis • Raff • Roberts • Walter
Cell Bio Spring-2015
1
Ch-1 Introduction to Cells
May-12-2015
Chapter 1
Introduction to Cells
A colony of bacteria, a butterfly, a rose, and a dolphin are all made of cells.
They all have a fundamentally similar chemistry and operate according to the same basic principles. Cell Bio Spring-2015
2
Ch-1 Introduction to Cells
May-12-2015
Cells were discovered in 1665 by Robert Hooke
Early studies of cells were conducted by
Mathias Schleiden (1838)
Theodor Schwann (1839)
Schleiden and Schwann proposed the Cell Theory
Cell Theory
1. All organisms are composed of cells
2. Cells are the smallest living things
3. Cells arise only from pre-existing cells
All cells today represent a continuous line of descent from the first living cells
Cell Bio Spring-2015
3
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
4
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
5
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
6
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
7
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
8
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
9
Ch-1 Introduction to Cells
May-12-2015
Electron microscopes
Transmission electron microscopes transmit electrons
through the material
Cell Bio Spring-2015
10
Ch-1 Introduction to Cells
May-12-2015
Electron microscopes
Scanning electron microscopes beam electrons onto the
specimen surface
Cell Bio Spring-2015
11
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
12
Ch-1 Introduction to Cells
May-12-2015
Basic structural similarities
1. Nucleoid or nucleus where DNA is located
2. Cytoplasm
Semifluid matrix of organelles and cytosol
3. Ribosomes
Synthesize proteins
4. Plasma membrane
Cell Bio Spring-2015
Phospholipid bilayer
13
Ch-1 Introduction to Cells
May-12-2015
Ribosomes
Cell’s protein synthesis machinery
Found in all cell types in all 3 domains
Ribosomal RNA (rRNA)-protein complex
Protein synthesis also requires messenger
RNA (mRNA) and transfer RNA (tRNA)
Ribosomes may be free in cytoplasm or associated with internal membranes
Cell Bio Spring-2015
14
Ch-1 Introduction to Cells
May-12-2015
Endomembrane System
Series of membranes throughout the
cytoplasm
Divides cell into compartments where different cellular functions occur
One of the fundamental distinctions between eukaryotes and prokaryotes
Cell Bio Spring-2015
15
Ch-1 Introduction to Cells
May-12-2015
Prokaryotic Cells
Simplest organisms
Lack a membrane-bound nucleus
DNA is present in the nucleoid
Cell wall outside of plasma membrane
Do contain ribosomes (not membrane-bound
organelles)
Two domains of prokaryotes
Archaea
Bacteria
Cell Bio Spring-2015
16
Ch-1 Introduction to Cells
May-12-2015
Eukaryotic Cells
Possess a membrane-bound nucleus
More complex than prokaryotic cells
Hallmark is compartmentalization
Achieved through use of membrane-bound
organelles and endomembrane system
Possess a cytoskeleton for support and to maintain cellular structure
Cell Bio Spring-2015
17
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
18
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
19
Ch-1 Introduction to Cells
Cell Bio Spring-2015
May-12-2015
20
Ch-1 Introduction to Cells
May-12-2015
Nucleus
Repository of the genetic information
Most eukaryotic cells possess a single nucleus
Nucleolus – region where ribosomal RNA
synthesis takes place
Nuclear envelope
2 phospholipid bilayers
Nuclear pores – control passage in and out
In eukaryotes, the DNA is divided into multiple linear chromosomes
Chromatin is chromosomes plus protein
Cell Bio