biology notes

✦✦✦✦   LYSOSOMES ✦✦✦✦ DEFINITION;  ➤ LYSOSOMES ARE CYTOPLASMIC ORGANELLES AND ARE DIFFERENT FROM OTHER DUE TO THEIR MORPHOLOGY. DISCOVERED BY; ➤ THESE WERE ISOLATED AS A SEPARATE COMPONENT FOR THE FIRST TIME   BY DE DUVE (1949).     CHRISTIAN RENE DE DUVE MEANINGS; ➤ LYSOSOMES ( LYSO= SPLITTING; SOMA= BODY ) ARE FOUND IN MOST EUKARYOTIC CELLS.   FUNCTION; ➤ ANY FOREIGN OBJECT THAT GAINS ENTRY INTO THE CELL IS IMMEDIATELY ENGULFED BY THE LYSOSOMES AND IS COMPLETELY BROKEN INTO SIMPLE DIGESTIBLE PIECES.  THE PROCESS IS KNOWN AS PHAGOCYTOSIS ( EATING PROCESS OF A CELL).  MOSTLY FOUND; ➤ THEY ARE MOST ABUNDANT IN THOSE ANIMAL CELLS WHICH EXHIBIT PHAGOCYTIC ACTIVITY.   BOUNDED BY; ➤ THEY ARE BOUNDED BY A SINGLE MEMBRANE AND ARE SIMPLE SACS RICH IN ACID PHOSPHATASE AND SEVERAL OTHER HYDROLYTIC  ENZYMES. THESE ENZYMES ARE SYNTHESIZED ON RER AND ARE  FURTHER PROCESSED IN THE GOLGI APPARATUS.  AUTOPHAGOSOME; (AUTOPHAGY) THE...

★★★ VACUOLES ★★★ DEFINITION; ➤ VACUOLES ARE FLUID FILLED SINGLE MEMBRANE BOUND ORGANELLES.    CELLS HAVE MANY SMALL VACUOLES IN THEIR CYTOPLASM. PRESENCE; ➤ ALTHOUGH VACUOLES ARE  PRESENT IN BOTH ANIMAL AND PLANT CELLS. MOSTLY FOUND; ➤ THEY ARE PARTICULARLY LARGE AND ABUNDANT IN PLANT CELLS    OFTEN OCCUPYING A MAJOR PORTION THE CELL VOLUME AND     FORCING THE REMAINING INTRACELLULAR INTO A THIN  PERIPHERAL LAYER .   BOUNDED BY; ➤ THESE VACUOLES ARE BOUNDED BY A SINGLE MEMBRANE AND     ARE FORMED BY THE COALESCENCE OF SMALLER VACUOLES    DURING PLANT'S GROWTH AND DEVELOPMENT. FUNCTION; ➤ VACUOLES SERVE TO EXPAND THE PLANT CELL WITHOUT DILUTING      ITS CYTOPLASM. ➤ ALSO FUNCTION AS THE SITE FOR THE STORAGE OF WATER AND CELL     PRODUCT OR METABOLIC INTERMEDIATES. IMPORTANCE; ➤ THE PLANT VACUOLE IS THE MAJOR CONTRIBUTOR TO THE TORGOR THAT    PROVIDES SUPPORT TO THE INDIVIDUAL PLANT C...