2.1.1 Components of a Cell

  1. Each cell consists of a plasma membrane and protoplasm
  2. The protoplasm consist of cytoplasm and nucleus.
  3. Cytoplasm contains many types of organelles.
  4. The following is the illustration of the animal cell and plant cell.
(Animal Cell)


(Plant Cell)

Non-Organelle

Plasma Membrane

  1. The plasma membrane separates the content of the cell from its external environment.
  2. It regulates the movement of substances entering and leaving the cell.
  3. It also allows the exchange of nutrients, respiratory gases and wastes products between the cell and its environment

Cytoplasm

  1. The cytoplasm contain variety of organelle.
  2. The function of the cytoplasm is to maintain the shape of the cell.
  3. It acts as a medium for the biochemical reactions occur within the cell
  4. It also store chemical substances such as glicogen granules (in animal cells), starch granules (inplant cells) and enzymes.


Cell Wall

  1. The cell wall only contain in plant cell. It support the cell and the plant and maintain the shape of the cell.
  2. It also prevents the cell from bursting when too much water enters the cell through osmosis.
  3. It allows substances to move through it.

Nucleus

  1. The nucleus contains the genetic material of a cell.
  2. It controls the activities of the cell.
  3. It also produces ribosomes and ribonucleic acids(RNA).

Organelle

Endoplasmic Recticulum (ER)

- Rough Endoplasmic Recticulum:

  1. Transporting the newly synthesised protein.
  2. Involve in the systhesis of protein.
  3. Provides surface for chemical reaction

- Smooth Endoplasmic Recticulum:

  1. Transporting lipids and glycerols.
  2. Synthesising lipids and other non-protein substances.

Mitochonrion

  1. Produces ATP (Adenosine triphosphate.)
  2. Site of energy production through cellular respiration.

Ribosomes

  1. Site for synthesising protein.
  2. Golgi Apparatus
  3. Site for the production of enzyme andlysosome.
  4. Produces polysacharides, glycoproteins andsecretory enzyme.
  5. Storing and modifying carbohydrate and glycoprotein.
  6. Transport and store lipid.

Vacuole

  1. Stores food (Carbohydrate, amino acid) and water.
  2. Support herbaceous plants when it is turgid.
  3. Stores organic waste (in leaf cells).

Chloroplast

  1. Contain chlorophyll and hence a site for photosynthesis to take place.

Centrosome


  1. The centrosome is served as the main microtubule organizing center (MTOC) of the animal cell as well as a regulator of cell-cycle progression.
  2. It form spindle fibres during cell division in animal cell.


Lysosomes


  1. Lysosomes contain hydrolytic enzymes that digest or break down complex organic molecules such as proteins, polysaccharides and lipids.
  2. The enzymes eliminate worn out organelles and damaged organelles.

Golgi Apparatus


  1. The golgi apparatus processes proteins and lipids from the endoplasmic reticulum
  2. The products are sorted by the Golgi Apparatus and packaged into vesicles
  3. The vesicles then release their contents outside the cell.
  4. It also responsible to the formation of lysosomes.