Organelles that work together in the business of life

and Cellular boundaries

• 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

Cell membrane (plasma membrane)

Animal cell

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

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

Hydrophilic head

Hydrophobic tails

water loving

water fearing

Lipid bilayer

Protein

Protein

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