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• Eukaryotic cells can be divided into two major parts: _________ and _________
• These two parts of the cell work together in the business of life
• Cytoplasm is the gel-like fluid portion of the cell outside of the nucleus
In our drawings, the blue background represents the cytoplasm
the nucleus the cytoplasm
What is the role of the nucleus?
• The nucleus contains nearly all the cell’s DNA and with it, the coded instructions for making proteins and other important molecules
• It will control most cell processes• Prokaryotic cells do not have nuclei, but they
do have DNA which has the same role
Nucleus
nucleolus
ribosomes
nuclear envelope
chromosome containing the cell’s DNA- only seen when the cell is dividing otherwise DNA is coiled around proteins in a structure called chromatin
Nucleus
nucleolus
ribosomes
nuclear envelopenuclear pore
chromosome containing the cell’s DNA- only seen when the cell is dividing otherwise DNA is coiled around proteins in a structure called chromatin
Cell boundaries
• All cells are surrounded by a barrier that separates it from its environment
• This barrier controls the material that enter and leave the cell
• It is called the cell membrane or the plasma membrane
• In addition to the cell membrane, many organisms have cell walls
Cell boundaries• The main function of the cell wall is to
support the cell and help it to maintain its shape; also for protection
• Many prokaryotic and eukaryotic cells have cell walls; however, animal cells do not
• Cell walls are porous enough to allow materials such as water, oxygen, carbon dioxide and other substances to pass through easily
Almost all cell membranes are made of a double layer called a lipid bilayer
This cell membrane example is made up of phospholipid
Remember: a phospholipid contains a phosphate group
a glycerol
two fatty acid chains
Lipid bilayer
Detailed view of the cell membrane
Remember: a phospholipid contains a phosphate group
a glycerol
two fatty acid chains
Hydrophilic head
Hydrophobic tails
water loving
water fearing
Hydrophilic head
Hydrophobic tails
water loving
water fearing
Lipid bilayer Carbohydrate
Cholesterol
Also known as a Fluid Mosaic ModelIt is called fluid because it is flexible and movesIt is called mosaic because it is made of many different molecules
Protein
Protein
It is selectively permeable or semi-permeable because it allows some substances to pass across but not other
Almost all cell membranes are made of a double layer called a lipid bilayer
This cell membrane example is made up of phospholipidRemember: a phospholipid contains
a phosphate group
a glyceroltwo fatty acid chains
Hydrophilic head
Hydrophobic tails
water lovingwater fearing
Lipid bilayer
Carbohydrate
CholesterolFluid Mosaic Model
flexible and moves
made of many different molecules Protein