as energy transferring organelles

in post translational modification of proteins and glycosidation of lipids

in trapping the light and transforming it into chemical energy

in digensting proteins and carbohydrates

Mesosome

Peroxisome

Ribosome

ER

Lysosomes - optimally active at a pH of about 8.5

Centrioles - sites for active RNA synthesis

Thylakoids - flattened membranous sacs forming the grana of chloroplasts

Ribosomes - those on chloroplasts are larger (80s) while those in the cytoplasm are smaller (70s)

Na⁺ and K⁺ ions move across cell membrane by passive transport

Lipids are arranged in bilayer with polar heads towards the inner part

Proteins make up 60 to 70% of the cell membrane

Fluid mosaic model of cell membrane was proposed by singer and Nicolson