Three main parts of the cell

Cell Theory

• All living organisms are composed of one or more cells

• The cell is the basic unit of structure and organisation

• all cells arise only from pre-existing cells

Universal similarities between cells

• DNA as the heritable material, RNA as a messenger and proteins as the workers

• Major cellular organelles - functions and arrangements within the cell

• ATP as an energy source

The central dogma

DNA → RNA → PROTEIN

Prokaryote cell vs Eukaryote cell

Both have

• Plasma membrane, cytosol, DNA, RNA, protein and ribosomes
  

• Eukaryotic cells have membrane-bound organelles and are much larger
  

• Prokaryote cells lack a membrane-bound nucleus

Cytoplasm

• is everything inside the plasma membrane including the organelles, but not including the nucleus

• the fluid portion of it is cytosol

  • water plus dissolved and suspended substances

Major organelles in the cytoplasm

• nucleus

• endoplasmic reticulum (smooth and rough)

• golgi apparatus

• lysosomes

• mitochondria

• ribosomes