Post on 13-Dec-2015
The Cell
• Outside of cells is extracellular fluid.
• Inside the cell is an aqueous solution called cytosol in which many organelles are suspended.
• The cell membrane separates the cytosol from the extracellular fluid.
Cell Membrane
• Controls what enters and exits the cell• Gives the cell shape and support• Composed of a bilayer (double layer) of
lipid (fat) molecules. These molecules are called phospholipids.
• Proteins and carbohydrates are embedded in the phospholipid bilayer.
• Found in both plant and animal cells.
Cell Membrane• Each phospholipid consists of a head that
is hydrophilic and two tails that are hydrophobic.
• Hydrophilic = water loving• Hydrophobic = water fearing
Cell Wall
•Gives the cell structure and shape.
•Lining surrounding the cell membrane.
•Found only in plant cells.
Cytoplasm
• Jelly-like substance located between the nucleus and cell membrane.
• Nutrients are absorbed, transported, and processed.
• All organelles are suspended by this fluid called cytoplasm.
Nucleus
• The control centre of the cell; directs all of the cell’s activities
• The nucleus is separated from the cytoplasm by the nuclear envelope. The envelope is filled with nucleic acids, such as DNA and RNA.
• Found in both plant and animal cells.
Ribosomes
• Produce proteins• Can be free-floating or attached to
membranes.• Found in both plant and animal cells.
Endoplasmic Reticulum (ER)
• Membranous tubes and canals that connect with the nuclear envelope.
• There are two types of ER:
– Rough ER: containing attached ribosomes and thus manufacture proteins.
– Smooth ER: manufacture fat molecules
• The products of the ER pinch off as vesicles and travel to the golgi apparatus.
• Found in both plant and animal cells.
Golgi Apparatus
• Membranous tubes that are stacked.• Chemically change the protein and fat
produced in the ER and are packaged into vesicles.
• These vesicles then travel through the cytoplasm and release the contents in the extracellular fluid to be used by cells.
• Found in both plant and animal cells.
Lysosomes
• Some vesicles produced by the golgi apparatus are lysosomes.
• Contain proteins and can digest particles as well as potentially dangerous microorganisms (bacteria or viruses) that could harm the cell.
• Called “suicide sacs” because they can decompose an entire cell if it is old or damaged.
• Found only in animal cells.
Mitochondria
• The powerhouse of the cell.• Carries out cellular respiration.• Cells which require large amounts of
energy, such as muscle cells, will contain large numbers of mitochondria.
• Found in both plant and animal cells.
Vacuoles
• Membrane-bound sacs filled with a watery solution containing sugars, minerals, and proteins.
• The water creates a pressure which helps keep the cell membrane pressed firmly against the cell.
• Plant cells have large vacuoles which results in the firm texture of vegetables such as celery.
• Found in both plant and animal cells.
Chloroplasts
• Carry out photosynthesis.• Contains the green pigment chlorophyll
which helps begin the process of photosynthesis and gives plants their green colour.
• Found only in plant cells
and algae.
Cell Structure vs. City StructureCell Structure City Structure Function
Nucleus King’s Castle Control for all activities
DNA King/Queen Controlling body
Ribosomes Merchants Production of products
ER Secret Passages Transport of important materials
Golgi Apparatus Sewage system Packaging and Secretion
Lysosomes Guards Fights off intruders
Cytoplasm Infrastructure & logistics Movement
Mitochondria Power Supply Provides energy for all activities
Cell membrane City wall Protection, limits
Vacoules Rooms Storage for materials