Division of Parts of Cell
1. Cell Membrane/Plasma Membrane
1. Nuclear Membrane
1. Organelles (Living)
2. Inclusion (Non-living, Temporary)
The cell membrane is the bilayer (two layers) of phospholipid molecules composed of the hydrophilic part and hydrophobic part.
|Outer parts of both phospholipid layer is a hydrophilic part (i.e soluble in water).
|Inner part of both phospholipid layers form the middle part - hydrophobic part (i.e not soluble in water).
Two outer surfaces→ hydrophilic
Inner central part → hydrophobic
Within this bilayer of phospholipid, proteins are embedded.
|Protein present through the vertical length of membrane → called as integral protein (transmembrane protein)
|Protein present in the inner aspect of the membrane near the transmembrane protein called → peripheral protein.
Similarly, it consists of carbohydrate molecules as glycoprotein and glycolipid commonly called as glycocalyx.
Function of lipid bilayer
It is permeable to fat-soluble substances (such as 02, Co2) but impermeable to water-soluble substances like ions, glucose, urea & other.
Thus, for these ions, glucose, for their transport inside the cell, proteins are present as water channels, Na-K pump, transporter.
Function of cell membrane
|• It forms the boundary of the cell.
|• Maintains the shape of the cell.
|• Acts as a selective barrier that regulates the passage of certain materials into or out of the cell.
|• Serves as the site of the receptor (protein act as receptor).
|• Limits the protoplasmic content of the cell.
Organelles are the living highly organized physical structures.
Two types of organelles: -
1) Membrane bounded
4) Endoplasmic reticulum
5) Golgi complex.
3) Microfilament and Microtubules
They are the structures present in the cytoplasm which are non-living, temporary constituents of the cell membrane.
1) Stored foods (i.e CHO, Proteins & Fats)
2) Secretory granules
3) Pigment granules
Cytoskeleton of cell:
Complex network of microtubules, microfilaments, and Intermediate filaments.
1) Provides shape of the cells
2) Gives support to the cell
3) Participates in the movement of organelles, vesicles.
Difference between organelles & inclusions
|• Permanent components of cell
||• Temporary components
|• Highly organized physical Structure
||• They are raw food materials or product of metabolism
|• Eg. Mitochondria, ER, Golgi bodies
||• Eg: Secretory granules, pigment, CHO, Protein
Difference between RNA & DNA
|• Found in nucleus (99%), mitochondria (1%)
||• Found in the cytoplasm (90%), nucleus (10%.)
|• nitrogen bases are Adenine, Guanine, cytosine, Thymine
||• Nitrogen bases are Adenine, Guanine, cytosine, Uracil
|• Contain deoxyribose sugar
||• Contain ribose sugar
|• Sum of purine bases is equal to the sum of pyrimidine bases.
||• Sum of the purine base is not equal to the sum of pyrimidine bases.
Carry genetic information.
Translate genetic information of DNA into protein
|• Histone protein present.
||• Histone protein absent.
|• Polymer of deoxy-ribonucleotides
||• Polymer of ribonucleotides