Introduction To Cell Structure

INTRODUCTION TO CELL STRUCTURE

INTRODUCTION  Cell is the structural and functional unit of all life forms . They vary in shape , size and number , not only in different organisms but also in various parts of same body . It is first discovered by Robert Hook in 1665.

Structure  All thought cells vary in shape and size but all cells have 3 major , viz plasma membrane , nucleus and cytoplasm.

Plasma or cell membrane 1 It is the outer covering of each cell , separately its contents from the surrounding medium. It is made up of lipids and proteins. It regulates the movement of molecules in and out of the cell. Plant cell has additional cell wall also made up of cellulose.

Nucleus  It is spherical or oval in shape usually located near the center of cell . Its membrane is called nuclear membrane . The chief components of nucleus are :  A) Chromatin material  B) Nucleolus

Chromatin It consist of D N A which responsible for story and transmitting the hereditary information from one generation to another.

Nucleolus  Nucleolus contains R N A which is helpful in protein synthesis .

Cytoplasm  It contains various cell organelles .Those are :1 Endoplasmic Reticulum 2 Golgi Apparatus 3 Lysosomes 4 Peroxisomes 5 Mitochondria 6 Plastids

Endoplasmic Reticulum  It is a membranous network, enclosing a fluid – filled lumen . It is of 2 type 1) Rough Endo Reti :- Ribosome are attached on its surface for synthesizing proteins. 2) Smooth Endo Reti :- It is without Ribosome's for sure thing lipids .

Golgi Apparatus  It consist of set of smooth flat sac like structures. It packages the material synthesized in E R and dispatches it to intracellular and extra cellular targets it is also invalved in the formation of lysosomes and peroxisomes .

Lysosomes  They are membrane-bound vesicles which destroy any foreign material like bacteria etc. present inside the cell. They also remove the worn out organelle and also digst the entire damaged or dead cell. They are also called the suicide bags or digestive bags .

Peroxisomes  They are small membrane bound sacs and are found in bidney and are found in liver and bidneys .

Mitochondria  These contain enzymes for cellular respiration in which energy is released and hence are called power house of cell.

Plastids  These are found in plant cells only. The green coloured are called chloroplasts which are present in chlorophyll which helps in photosynthesis .

Submitted By:     

Harjeet Singh Amit Kumar Dharampal Ravi Kaler Sukdev Singh

Guided By:  S.Major Singh  Md.Jasleen Kaur