APPRECIATING THE UNIQUENESS OF THE CELL

Learning Outcomes: At the end of the lesson, students should be able to Predict the state of certain cell without a particular cellular components Discuss the synthesis and secretion of substances synthesized in the cell

A cell is the basic unit of all living organisms that is capable of functioning on its own. The presence of organelles divides the cell into small compartments in which specific function can take place.

Table 1 The effects of the absence of certain cellular components in animal and plant cellOrganelles The resulting cell conditionPlasma membrane No regulation of substansces entering and leaving the cellCell wall Plant cell loses its shape and turgidity, excessive uptake of

water will lead the cell to burstCytoplasm There no place to house the organellesNucleus Cellular activities cannot be carried out and cell dies after

a short timeRough ER The transportation of protein synthesized by ribosomes is

disruptedSmooth ER The synthesis and transportation of lipid and glycerol is

disruptedGolgi Apparatus Cell cannot packages, modifies, transports and secretes

digestive enzymes, certain hormones and mucus Mitochondria Cell doesnot have energy to perform cell activityLysosomes No intracellular digestion of food, bacteria, worn out

organelles, old or damaged cellRibosomes Cell doesnot be able to synthesis protein and growth is

retardedChloroplast Cells do not have chlorophyll to absorb light for

photosynthesisVacuole The cell become flaccid and plant could dehydrate and

dies, no space to store soluble food and waste productCentriole Spindles would not be formed during division of animal

cell

Protein Synthesis and Secretion

1. Nucleus – sends information to ribosomes to synthesis protein2. Ribosomes – synthesis the protein3. Rough ER – transport the protein synthesized by ribosomes 4. Transport vesicle – pinched off from RER to fuse with Golgi apparatus5. Golgi apparatus – modifies protein into substansces required by body ( such as

hormones) and packages the modified protein in a vesicle6. Secretory vesicle – pinched off from golgi apparatus and fuse with plasma

membrane to release the processed protein outside the cell7. Plasma membrane