Parts of Cell and their Functions
- Generally found in plant and fungus cell.
- Freely permeable.
- It is made up of cellulose (plant) and chitin (fungus).
- It provides shape and rigidity to the cell.
- It is also known as plasma membrane / cytoplasmic membrane / plasmalemma
- In animal cell it is the outer cover of the cell.
- In plant cell it is found within cell wall.
- Cell membranes contain a variety of biological molecules, notably lipids and proteins.
- The cell membrane is selectively permeable and able to regulate what enters and exits the cell, thus facilitating the transport of materials needed for survival..
- Protoplasm is the living part of a cell that is surrounded by a plasma membrane.
- It is generally the whole fluid present inside plasmamembrane.
- It contains the genetic material of a cell or organism
- It plays a role in controlling the activity of the cell.
- It consists of Cytoplasm & Nucleoplasm.
- Cytoplasm: The fluid found outside the nuclear membrane.
- Nucleoplasm: The fluid found inside the nuclear membrane.
- The mitochondrion (/ˌmaɪtəˈkɒndrɪən/, plural mitochondria) is a semi autonomous double-membrane-bound organelle found in most eukaryotic organisms.
- It is called as “Powerhouse of the Cell” because in it stepwise oxidation of fuel occurs which results in release of chemical energy. This energy is stored in the form of ATP.
- Mitochondria play a vital role in the conversion of energy from food into energy for biological processes.
- These are hollow membranous system having ribosomes (thus called Rough ER) or no ribosomes (thus called Smooth ER).
- Rough Endoplasmic Reticulum is the site of protein synthesis, while Smooth Endoplasmic Reticulum is the site of synthesis of steroids and detoxification.
- Also known as Golgi boy or Golgi Complex.
- It was identified in 1897 by the Italian scientist Camillo Golgi and was named after him in 1898.
- Plays important role in secretion, transportation and acrosome formation.
- Found in cells of plants, algae, and some other eukaryotic organisms.
- Plastids were discovered and named by Ernst Haeckel.
- They often contain pigments used in photosynthesis, and the types of pigments in a plastid determine the cell’s color.
- Different kinds of Plastids :
- Chloroplasts : green plastids for photosynthesis.
- Rhodoplasts : red plastids found in red algae.
- Chromoplasts : coloured plastids for pigment synthesis and storage.
- Leucoplasts : colourless plastids for monoterpene synthesis.
- Amyloplasts : for starch storage and detecting gravity (for geotropism).
- Elaioplasts : for storing fat
- Proteinoplasts : for storing and modifying protein
- Tannosomes : for synthesizing and producing tannins and polyphenols
- The red colour of tomatoes is due to the presence of lycopene pigment, i.e., chromophore.
- The colour of carrot is due to carotene.
- It is made up of ribonucleic acid (RNA).
- The term “ribosome” was proposed by scientist Richard B. Roberts in the end of 1950s:
- takes part in protein synthesis.
- lysosome is a membrane-bound cell organelle that contains digestive enzymes.
- Lysosomes are involved with various cell processes.
- They break down excess or worn-out cell parts. They may be used to destroy invading viruses and bacteria.
- The enzyme found in lysosome may digest the entire cell. This is why it is also known as suicidal bag.
- Chromosome is threadlike structure, found in the nucleus.
- Chromosome is a long DNA molecule with part or all of the genetic material of an organism.
- Beadlike structure found on chromosome is called genes, which are made up of DNA and are the carrier of genetic information from generation to generation. In some viruses, RNA is the genetic material called retrovirus.
- Eukaryotic cells possess many chromosomes.
- These are non-living reservoirs, bounded by a membrane called tonoplast.
- It stores toxic metabolic waste and helps in osmoregulation.
- It was discovered by Robert Brown.
- The nucleus is a membrane-bound organelle that contains genetic material (DNA) of eukaryotic organisms.
- Nucleus is rich in protein and RNA.
- Eukaryotes usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many.
- Among mammals only Camel and Llama’s red blood cells has nuclei.
- The main function of the cell nucleus is to control gene expression and mediate the replication of DNA during the cell cycle.
- It is the controlling centre of a cell.
- Complex organic compound found in cell.
- These contain the genetic instructions used in the development and functioning of all known living organisms.
- There are of two types nucleic acid – DNA and RNA.
- Full form Deoxyribo Nucleic Acid.
- DNA was discovered by James D Watson and Francis Crick, who got Nobel Prize for this discovery.
- Frederic Meischer first isolated DNA from nucleus of a cell.
- DNA is mainly found in nucleus. In Small amount it is also found in mitochondria and chloroplast.
- Chemically DNA is made up of three components – Nitrogen Base, Sugar and Phosphate Group.
- Nitrogen Bases are of two types – Purines & Pyrimidines.
- Purines contain two type of nitrogen base – Adinine and Guanine.
- Pyrimidines contain two type of nitrogen base – Thymine and Cytosine.
- Functions of DNA :
- It contains genetic information in coded form.
- DNA synthesizes RNA.
- Full form Ribo Nucleic Acid.
- RNA is a single stranded nucleic acid made up to phosphate, ribose sugar and nitrogenous base uracil,adenine, guanine and cytosine.
- It is found in nucleus as well as cytoplasm.
- Function: Synthesis of protein.