2.1 Cell, Cellular Components and Their Function

Theory of Cell

1. All organisms are made up of one or more cells ..
2. Cells are the fundamental and structural unit of life.
3. All cells come from pre-existing cells.

Non-organelle Structures of Cell

1. Plasma membrane
2. Cytoplasm
3. Cell wall (plant cell only)

Organelle Structures of a Cell

1. Nucleus
2. Endoplasmic Recticulum
3. Mitochondrion
4. Ribosom
5. Golgi apparatus
6. Vacuole
7. Chloroplast (plant cell only)

Plama Membrane

1. Separates the content of the cell from its external environment.
2. Regulates the movement of substances entering and leaving the cell.
3. Allows the exchange of nutrients, respiratory gases and wastes products between the cell and its environment

Cytoplasm

1. Maintain the shape of the cell.
2. Acts as a medium for the biochemical reactions occur within the cell
3. Storing chemical substances such as glicogen granules (in animal cells), starch granules (inplant cells) and enzymes.
4. Stores a variety of organelle.

Cell Wall

1. Support the cell and the plant.
2. Maintain the shape of the cell.
3. Prevents the cell from bursting when too much water enters the cell through osmosis.
4. Allows substances to move through it.

Endoplasmic Recticulum (ER)

Rough Endoplasmic Recticulum:

• Transporting the newly synthesised protein.
• Involve in the systhesis of protein.
• Provides surface for chemical reaction

Smooth Endoplasmic Recticulum:

• Transporting lipids and glycerols.
• Synthesising lipids and other non-protein substances.

Mitochonrion

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

Ribosomes

Site for synthesising protein.

Golgi Apparatus

• Site for the production of enzyme and lysosome.
• Produces polysacharides, glycoproteins and secretory enzyme.
• Storing and modifying carbohydrate and glycoprotein.
• Transport and store lipid.

Chloroplast

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