Cell Structure and Function  

What is Cell Structure and Function

The body is a community made up of its innumerable cells or inhabitants.

- Thomas A. Edison

The third chapter in the syllabus of NEET biology exam is cell structure and function. It is also the third unit in the NCERT textbook for class 11. The content of cell structure and function accounts for approximate 7% weightage for the biology section in the NEET exam. The chapter cell structure and function become highly scoring due to the interesting concepts it offers. Furthermore, the concepts of this chapter come in very handy while preparing the plant tissues, animal tissues as well as reproduction chapters. Therefore, cell structure and function need not be taken lightly as it allows an easy grasp of other important chapters. 

 

After reading the cell structure and function, you will be able to understand the structural details of prokaryotic and eukaryotic cells that include:

  • Bacterial cell
  • Plant cell
  • Animal cell
  • Human cell

 

In order to have an organized study plan, you will require study notes on cell structure and function so that the details of the topics are not missed. Therefore, let us have an in-depth look into the chapter notes of cell structure and function.

Animal Cell and Plant Cell

Notes on Cell Structure and Function

1. Cell: The Unit of Life

This topic deals with the structural details of the cell along with its functional aspects. It is the fundamental chapter that builds up the understanding of the cell. As you would finish reading this chapter, you will be able to establish the definition of a cell, the types of cells and various organelles found in a eukaryotic cell, such as-

  • Nucleus - the control centre of the cell. It stores the heredity information in the chromatin network.
  • Mitochondrion- the powerhouse of the cell. It synthesizes ATP during the cellular respiration.
  • Plastids - the kitchen of the cell in the form of chloroplasts. Plastid is a collective term for chloroplasts, chromoplasts, and leucoplasts.
  • Endomembrane system - the packaging and transportation system of the cell. It comprises of the nuclear membrane, endoplasmic reticulum, Golgi apparatus, vacuole, lysosomes and vesicles.
  • Ribosomes - the protein factory of the cell.
  • Cytoskeleton - the proteinaceous skeleton of the cell that includes the microtubules and intermediate filaments.

 

There is also an exhaustive account of the models of the cell membrane. The fluid mosaic model of the cell membrane is crucial for the NEET exam. The structural, as well as functional details of the cell wall, are also dealt with in the chapter cell structure and function. Hence, a profound reading of this chapter will give you a conceptual buildup of the cell, its structure, its function and different types of cells. Not only the prokaryotic and eukaryotic cells are differentiated but the differences between a bacterial cell, an animal cell and a plant cell are also well described. 

 

2. Biomolecules

The life initiated with the formation of the cell. However, a cell itself is a composition of various chemicals or polymers that undergo specific chemical reactions in order to make sure that the structural stability and functional continuity of the cell are maintained. Hence, an understanding of cell structure and function is incomplete without knowing the biomolecules. 

The biomolecules are defined as the complex polymer and chemicals that are present in the cellular pool. The biomolecules come out to be similar to the chemicals present in the soil. However, the beauty of life lies in the fact that there is a relative abundance of carbon and hydrogen with respect to other elements is higher in any living organism than in earth’s crust. Hence, the biomolecules are organic compounds that perform the chemical reaction to maintain the sustainability of life. 

 

 

There are four principal forms of biomolecules that are discussed in details:

  1. Carbohydrates: polymers of monosaccharides
  2. Proteins: polymers of amino acids
  3. Nucleotides: polymers of nucleic acids
  4. Fats: these are not polymers but fall under the category of macromolecules owing to their hydrophobic nature. 

 

MACRONUTRIENTS

 

The monomers of these biomolecules are connected via special glycosidic bonds as:

  • Glycosidic bonds in carbohydrates
  • Peptide bonds in proteins
  • Phosphodiester bonds in nucleic acids

These are the sources of immense energy when broken by enzymatic action. The chapter biomolecules also deal with primary and secondary metabolites, enzymes and properties of water. Therefore, this chapter is crucial for the understanding of topics such as photosynthesis, respiration, and genetics. You will also come across a similar topic in your chemistry syllabus as well. Hence, one can easily infer the hidden importance this chapter has!

 

3. Cell Cycle and Cell Division

 

CELL Cycle

 

It is a known fact that every living organism began its life as a single cell. For multicellular organisms, the complexity begins as the number of cells increase. So, what is responsible for increasing the number of cells? The answer lies in this fascinating chapter cell cycle and cell division. The chapter defines the cell cycle and explains the different phases of the cell cycle, that is, interphase and dividing phase. The two basic types of cell division are thoroughly discussed as:

  1. Mitosis or equational cell division
  2. Meiosis or reductional cell division

The substages of the cell division, that is, karyokinesis and cytokinesis are also thoroughly discussed. The karyokinesis can be further classified into four substages as follows:

  1. Prophase: In this phase, the chromatin is condensed. The nuclear membrane and nucleolus are disintegrated. In the case of animal cells, centriole movement and spindle formation are seen.
  2. Metaphase: In this phase, the chromosomes are visible as distinguished units. 
  3. Anaphase: In this phase, the separation of the sister chromatids occurs.
  4. Telophase: This phase reverses the events of prophase.

Further, the chapter cell cycle and cell division deal with the significance of mitotic and meiotic cell divisions. Hence, this chapter does not only have individual significance but is equally crucial when it comes to the understanding of concepts of chapters reproduction and genetics. Therefore, you will have to be very attentive while studying this chapter. As you can already see, there will be a requirement of building concepts rather than mugging up the details. 

 

Tips on Cell Structure and Function

Let us see how you can develop a grip on the concepts of cell structure and function.

  • An analysis of the previous years' NEET question papers reveals both conceptual as well as straight forward questions. Therefore, you will begin the building up of basics from the coveted NCERT textbook for class 11.
  • Once you have thoroughly read the NCERT text, you will need to refer to additional sources for expanding the conceptual clarity. This is especially required for the topic of cell types in cell structure and function.
  • The diagrams of the organelles have to be covered from the NCERT. 
  • Do a comparative study of the bacterial cell, animal cell, and plant cell. This will help in cracking the questions based on compare and contrast.
  • The topic biomolecules under cell structure and function is an exhaustive chapter. Refer to the concepts from chemistry while studying this chapter.
  • The topic cell cycle and cell division are purely conceptual will easily comprehensible topics. A thorough read-up and subsequent practice of mock questions will allow you to retain the concepts easily. 
  • Lastly, keep revising the concepts in order to make sure you do not miss the details. Before preparing for the chapters reproduction and genetics, it would be wise if you brush-up cell structure and function.

 

Books to Refer to Cell Structure and Function

  • The NCERT textbook for class 11

  • A Textbook of CBSE Biology for Class 11 by Sarita Aggarwal

  • Trueman’s Elementary Biology Volume 1

 

Biology Units-wise Notes for Medical Exams

Units No.

Units Name

Unit 1

Diversity in Living World

Unit 2

Structural Organisation in Animals and Plants

Unit 4

Plant Physiology

Unit 5

Human Physiology

Unit 6

Reproduction

Unit 7

Genetics and Evolution 

Unit 8

Biology and Human Welfare

Unit 9

Biotechnology and Its Applications 

Unit 10

Ecology and Environment 

Topics from Cell Structure and Function

  • Cell theory and cell as the basic unit of life ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (14 concepts)
  • Structure of prokaryotic and eukaryotic cell ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (41 concepts)
  • Plant cell and animal cell ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (3 concepts)
  • Cell envelope, cell membrane, cell wall ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (32 concepts)
  • Cell organelles-structure and function ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (7 concepts)
  • Endomembrane system-endoplasmic reticulum, Golgi bodies, lysosomes, vacuoles; mitochondria, ribosomes, plastids, micro bodies ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (5 concepts)
  • Cytoskeleton, cilia, flagella, centrioles (ultra structure and function) ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (4 concepts)
  • Nucleus-nuclear membrane, chromatin, nucleolus. ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (4 concepts)
  • Chemical constituents of living cells: Biomolecules-structure and function of proteins, carbodydrates, lipids, nucleic acids ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (46 concepts)
  • Enzymes-types, properties, enzyme action ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (30 concepts)
  • B Cell division: Cell cycle, mitosis, meiosis and their significance. ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (33 concepts)
  • Cell: The Unit of Life ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (25 concepts)
  • Biomolecules ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (29 concepts)
  • Cell Cycle and Cell Division ( NEET, AIIMS MBBS, JIPMER MBBS, KVPY SA, KVPY SB/SX ) (13 concepts)

Important Books for Cell Structure and Function

  • Cell Structure and Function Book
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