Lecture 8 - Eukaryotic cell – An Overview | Cell Biology- Botany PDF Download

 Page 1


Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 
 
 
 
 
 
 
 
 
 
 
Lesson: Eukaryotic cell – An Overview 
Lesson Developer : Manju A. Lal 
College/Department : Kirori Mal College, University of Delhi 
Page 2


Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 
 
 
 
 
 
 
 
 
 
 
Lesson: Eukaryotic cell – An Overview 
Lesson Developer : Manju A. Lal 
College/Department : Kirori Mal College, University of Delhi 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 1 
 
Table of Contents      
Chapter: Eukaryotic Cell 
? Introduction 
? Cell Wall 
? Plasma membrane 
? Cytoplasm 
? Nucleus 
? Organelles involved in various metabolic reactions 
? Mitochondria 
? Chloroplasts 
? Peroxisomes 
? Endomembrane system 
? Endoplasmic reticulum 
? Golgi apparatus 
? Lysosomes 
? Vacuoles 
? Ribosomes 
? Cytoskeleton 
? Origin and Evolution of eukaryotic cell 
? Origin of cell 
? Origin of biomolecules 
? The first cell 
? Evolution of Eukaryotic cells 
? Summary  
? Exercise/ Practice 
? Glossary 
? References/ Bibliography/ Further Reading 
 
 
Page 3


Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 
 
 
 
 
 
 
 
 
 
 
Lesson: Eukaryotic cell – An Overview 
Lesson Developer : Manju A. Lal 
College/Department : Kirori Mal College, University of Delhi 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 1 
 
Table of Contents      
Chapter: Eukaryotic Cell 
? Introduction 
? Cell Wall 
? Plasma membrane 
? Cytoplasm 
? Nucleus 
? Organelles involved in various metabolic reactions 
? Mitochondria 
? Chloroplasts 
? Peroxisomes 
? Endomembrane system 
? Endoplasmic reticulum 
? Golgi apparatus 
? Lysosomes 
? Vacuoles 
? Ribosomes 
? Cytoskeleton 
? Origin and Evolution of eukaryotic cell 
? Origin of cell 
? Origin of biomolecules 
? The first cell 
? Evolution of Eukaryotic cells 
? Summary  
? Exercise/ Practice 
? Glossary 
? References/ Bibliography/ Further Reading 
 
 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 2 
Introduction 
Living beingsare classified as eukaryotes and prokaryotes on the basis of presence or 
absence of well-defined nucleus. The eukaryotic cells are more complex than the prokaryotic 
cell. The presence of membrane bound organelles compartmentalizes the cell and its various 
functions. In a eukaryotic cell, nuclear envelope separates the nuclear activities from the 
rest of the cell. Between the nuclear membrane and the plasma membrane, cytoplasm is 
present, in whichvarious types of cell organelles are present. There are four main structural 
features of a typical eukaryotic cell: 
? The plasma membrane that separates and surrounds the cell. 
? Nucleus that contains the genetic material and directs the cellular functions. 
? The organelles that carry out various metabolic functions. 
? Cytoplasm. 
The organelles can be classified under three categories: 
? The organelles that are bound by double unit membranes such as nucleus, 
chloroplasts and mitochondria.  
? Organelles, which are bound by single unit membrane. The examples of this second 
class of organelles are Endoplasmic reticulum, Golgi apparatus, lysosomes, various 
types of vesicles including large vacuoles (in older plant cells), and peroxisomes.  
? Third category includes those organelles, which are not bound by any membrane, 
such as ribosomes, cytoskeletal structures.  
In this chapter you are going to have an overview of the eukaryotic cell. The organelles 
involved in energy transformation reactions, such as respiration and photosynthesis are 
referred under one category, while the organelles involved in dynamic equilibrium of 
membranes and protein movement are put under another category. Ribosomes and the 
cytoskeletal elements are dealt separately.  
As you have studied in the previous chapter, one of the important characteristics of living 
cell is presence of plasma membrane with selective permeability. Though, all the cell 
membranes including plasma membrane are made upoflipids and proteins, all of the cell 
membranes are different from each other in their chemical composition. 
The plant cell is different from that of animal cell because of the presence of cellulosic cell 
wall, plastids and the vacuoles.Large central vacuole is present in mature plant cells, while 
in animal cells the vacuoles are small and are many in number. In plants there are 
plasmadesmata which are the cytoplasmic connections in between cells, while these are 
Page 4


Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 
 
 
 
 
 
 
 
 
 
 
Lesson: Eukaryotic cell – An Overview 
Lesson Developer : Manju A. Lal 
College/Department : Kirori Mal College, University of Delhi 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 1 
 
Table of Contents      
Chapter: Eukaryotic Cell 
? Introduction 
? Cell Wall 
? Plasma membrane 
? Cytoplasm 
? Nucleus 
? Organelles involved in various metabolic reactions 
? Mitochondria 
? Chloroplasts 
? Peroxisomes 
? Endomembrane system 
? Endoplasmic reticulum 
? Golgi apparatus 
? Lysosomes 
? Vacuoles 
? Ribosomes 
? Cytoskeleton 
? Origin and Evolution of eukaryotic cell 
? Origin of cell 
? Origin of biomolecules 
? The first cell 
? Evolution of Eukaryotic cells 
? Summary  
? Exercise/ Practice 
? Glossary 
? References/ Bibliography/ Further Reading 
 
 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 2 
Introduction 
Living beingsare classified as eukaryotes and prokaryotes on the basis of presence or 
absence of well-defined nucleus. The eukaryotic cells are more complex than the prokaryotic 
cell. The presence of membrane bound organelles compartmentalizes the cell and its various 
functions. In a eukaryotic cell, nuclear envelope separates the nuclear activities from the 
rest of the cell. Between the nuclear membrane and the plasma membrane, cytoplasm is 
present, in whichvarious types of cell organelles are present. There are four main structural 
features of a typical eukaryotic cell: 
? The plasma membrane that separates and surrounds the cell. 
? Nucleus that contains the genetic material and directs the cellular functions. 
? The organelles that carry out various metabolic functions. 
? Cytoplasm. 
The organelles can be classified under three categories: 
? The organelles that are bound by double unit membranes such as nucleus, 
chloroplasts and mitochondria.  
? Organelles, which are bound by single unit membrane. The examples of this second 
class of organelles are Endoplasmic reticulum, Golgi apparatus, lysosomes, various 
types of vesicles including large vacuoles (in older plant cells), and peroxisomes.  
? Third category includes those organelles, which are not bound by any membrane, 
such as ribosomes, cytoskeletal structures.  
In this chapter you are going to have an overview of the eukaryotic cell. The organelles 
involved in energy transformation reactions, such as respiration and photosynthesis are 
referred under one category, while the organelles involved in dynamic equilibrium of 
membranes and protein movement are put under another category. Ribosomes and the 
cytoskeletal elements are dealt separately.  
As you have studied in the previous chapter, one of the important characteristics of living 
cell is presence of plasma membrane with selective permeability. Though, all the cell 
membranes including plasma membrane are made upoflipids and proteins, all of the cell 
membranes are different from each other in their chemical composition. 
The plant cell is different from that of animal cell because of the presence of cellulosic cell 
wall, plastids and the vacuoles.Large central vacuole is present in mature plant cells, while 
in animal cells the vacuoles are small and are many in number. In plants there are 
plasmadesmata which are the cytoplasmic connections in between cells, while these are 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 3 
absent in animal cells. Lysosomes are not evident in plant cells. At the time of cell division 
centrioles are present in animal cells, while these are absent in plant cells. 
 
 
Figure:Comparison between plant and animal cell 
Source:http://farm6.staticflickr.com/5350/7085820785_2c73334705_o.jpg 
 
 
Page 5


Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 
 
 
 
 
 
 
 
 
 
 
Lesson: Eukaryotic cell – An Overview 
Lesson Developer : Manju A. Lal 
College/Department : Kirori Mal College, University of Delhi 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 1 
 
Table of Contents      
Chapter: Eukaryotic Cell 
? Introduction 
? Cell Wall 
? Plasma membrane 
? Cytoplasm 
? Nucleus 
? Organelles involved in various metabolic reactions 
? Mitochondria 
? Chloroplasts 
? Peroxisomes 
? Endomembrane system 
? Endoplasmic reticulum 
? Golgi apparatus 
? Lysosomes 
? Vacuoles 
? Ribosomes 
? Cytoskeleton 
? Origin and Evolution of eukaryotic cell 
? Origin of cell 
? Origin of biomolecules 
? The first cell 
? Evolution of Eukaryotic cells 
? Summary  
? Exercise/ Practice 
? Glossary 
? References/ Bibliography/ Further Reading 
 
 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 2 
Introduction 
Living beingsare classified as eukaryotes and prokaryotes on the basis of presence or 
absence of well-defined nucleus. The eukaryotic cells are more complex than the prokaryotic 
cell. The presence of membrane bound organelles compartmentalizes the cell and its various 
functions. In a eukaryotic cell, nuclear envelope separates the nuclear activities from the 
rest of the cell. Between the nuclear membrane and the plasma membrane, cytoplasm is 
present, in whichvarious types of cell organelles are present. There are four main structural 
features of a typical eukaryotic cell: 
? The plasma membrane that separates and surrounds the cell. 
? Nucleus that contains the genetic material and directs the cellular functions. 
? The organelles that carry out various metabolic functions. 
? Cytoplasm. 
The organelles can be classified under three categories: 
? The organelles that are bound by double unit membranes such as nucleus, 
chloroplasts and mitochondria.  
? Organelles, which are bound by single unit membrane. The examples of this second 
class of organelles are Endoplasmic reticulum, Golgi apparatus, lysosomes, various 
types of vesicles including large vacuoles (in older plant cells), and peroxisomes.  
? Third category includes those organelles, which are not bound by any membrane, 
such as ribosomes, cytoskeletal structures.  
In this chapter you are going to have an overview of the eukaryotic cell. The organelles 
involved in energy transformation reactions, such as respiration and photosynthesis are 
referred under one category, while the organelles involved in dynamic equilibrium of 
membranes and protein movement are put under another category. Ribosomes and the 
cytoskeletal elements are dealt separately.  
As you have studied in the previous chapter, one of the important characteristics of living 
cell is presence of plasma membrane with selective permeability. Though, all the cell 
membranes including plasma membrane are made upoflipids and proteins, all of the cell 
membranes are different from each other in their chemical composition. 
The plant cell is different from that of animal cell because of the presence of cellulosic cell 
wall, plastids and the vacuoles.Large central vacuole is present in mature plant cells, while 
in animal cells the vacuoles are small and are many in number. In plants there are 
plasmadesmata which are the cytoplasmic connections in between cells, while these are 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 3 
absent in animal cells. Lysosomes are not evident in plant cells. At the time of cell division 
centrioles are present in animal cells, while these are absent in plant cells. 
 
 
Figure:Comparison between plant and animal cell 
Source:http://farm6.staticflickr.com/5350/7085820785_2c73334705_o.jpg 
 
 
Eukaryotic cell – An Overview 
Institute of Lifelong Learning, University of Delhi 4 
 
 
 
 
 
 
 
 
Embed Animation:Credit "Genetic Science Learning Center, University of Utah 
http://learn.genetics.utah.edu/content/begin/cells/insideacell/ 
 
Also visit for 
Animation:http://www.sumanasinc.com/webcontent/animations/content/eukary
oticcells.html 
Cell Wall 
 
Figure:Electron micrograph of a plant cell 
Source:http://figures.boundless.com/4ff32b98246b709a9cd78cbc/full/plantcell.gif (CC) 
Plant cells are different from animal cells due to the presence of cell wall. Since plants are 
non motile, they require a certain kind of rigidity. Cell wall provides the skeletal support to 
the plants. It is made up of cellulose microfibrils, which are embedded in matrix of other 
polysaccharides, such as hemicellulose and pectic substances, and a small amount of 
proteins is also present.