TOPIC 3
Cells
• All living organisms are made of cells
• Basic/smallest unit of structure and functioning of living things
• Most are microscopic and can be seen through a microscope
• Electron microscope shows more detail
• Unicellular (Amoeba) - made of 1 cell
• Multicellular - made of many cells
• Living cells are made of other living cells
Atom Molecule/ Organelle Cell
compound
Organism Body
Organ Tissue
system
The cell membrane / Plasmalemma
• Found in plant + animal cells
• Living
• Made of proteins + phospholipids
• Has a small opening: pores, allows substances to pass through by diffusion + osmosis, actively
transports (requires energy)
• Controls entering and exiting
• Holds content
Plasma membrane
• Made of phospholipids – two layers
Gluey pectin layer
• Protein molecules found in outer layer
• Protein carrier molecules Cellular air space
• Cholesterol molecules binds everything together
• Is selectively permeable
Cell wall
• Only found in plant cells
• Nonliving
• Contains Cellulose (carbohydrates)
• Permeable Primary cell wall
• Has large pits Secondary cell wall
• Substances pass through by diffusion
• Supports and protects the cell
• Cell walls joined together by thin layer called middle lamella
1. Primary cell wall - cellulose
2. Secondly cell wall - lignin
3. Middle lamella - pectin
Cells
• All living organisms are made of cells
• Basic/smallest unit of structure and functioning of living things
• Most are microscopic and can be seen through a microscope
• Electron microscope shows more detail
• Unicellular (Amoeba) - made of 1 cell
• Multicellular - made of many cells
• Living cells are made of other living cells
Atom Molecule/ Organelle Cell
compound
Organism Body
Organ Tissue
system
The cell membrane / Plasmalemma
• Found in plant + animal cells
• Living
• Made of proteins + phospholipids
• Has a small opening: pores, allows substances to pass through by diffusion + osmosis, actively
transports (requires energy)
• Controls entering and exiting
• Holds content
Plasma membrane
• Made of phospholipids – two layers
Gluey pectin layer
• Protein molecules found in outer layer
• Protein carrier molecules Cellular air space
• Cholesterol molecules binds everything together
• Is selectively permeable
Cell wall
• Only found in plant cells
• Nonliving
• Contains Cellulose (carbohydrates)
• Permeable Primary cell wall
• Has large pits Secondary cell wall
• Substances pass through by diffusion
• Supports and protects the cell
• Cell walls joined together by thin layer called middle lamella
1. Primary cell wall - cellulose
2. Secondly cell wall - lignin
3. Middle lamella - pectin
