A cell is a smallest unit of an organism that can live independently. There are two cell types: prokaryotic and eukaryotic cells. Prokaryotic cells include bacteria and a large group of other microorganisms with no nucleus. Eukaryotic cells include plant cell and animal cells, they have distinct nucleus and cell organelles.
How the cell maintains life using organelles?
The cell maintains life by assigning each responsibility to separate specialized machines. These machines are called organelles. An organelle is a compartmentalized structure that performs a specialized function within a cell. An animal cell contains a nucleus, ribosomes, mitochondria, rough endoplasmic reticulum, smooth endoplasmic reticulum, plasma membrane, Golgi apparatus and lysosomes. The nucleus controls the cell function.
Organelle structures and functions
Ribosomes: make proteins for the cell. Each ribosome is made of two protein subunits: the large subunit and the small subunit. The units clasp around a strand of nucleic acid instructions from the nucleus. The ribosome reads the strand instructions to make proteins for the cell to use in its normal activities.
Endoplasmic reticulum: Including rough ER and smooth ER. Rough ER is found attached to the outside of the nucleus. It appears rough because of the ribosomes on its surface. It helps the attached ribosomes in finishing protein synthesis. Smooth ER is NOT attached to the nucleus and DOES NOT have attached ribosomes (thus smooth). Smooth ER synthesizes carbohydrates and lipids.
The Golgi apparatus: made up of flattened, folded sacs, ships packages around the cell.
Mitochondria: converts carbohydrates taken from food into ATP -- produce energy to power the cell.
Lysosome: highly acidic, destroy waste to clean up the cell.
Cell Membrane: composition and function
A cell membrane is a selectively permeable structure that envelops the cell and protects the cell’s internal environment. The cell’s membrane is made of phospholipids, which have carbohydrate heads and lipid tails. Proteins can be embedded or anchored on cell membrane. Cell membranes provides a stable environment for cells, perform communication function among cells via the surface proteins, and selectively exchange material between a cell and its environment.