Lecture 3: Organelles & Mitochondria

Cytosol

area of the cell that isn’t occupied by organelles (the Free-space)

Why prokaryotes survive without membrane bound organelles and eukaryotic cells don’t

Eukaryotic cells have a smaller surface to volume ration & couldn’t survive with one membrane, while prokaryotes have small size & high surface to volume ratio

How membrane bound organelles came about

vagination of the plasma membrane

How mitochondria came to be 

Aerobic prokaryote engulfed a larger aerobic pre-eukaryotic cell creating a symbiotic relationship & two sets of DNA. 

Mitochondias’s functions outside of ATP synthesis 

• lipid biosynthesis 

• FeS complex creation 

• Pyrimidine Synthesis 

• Carrier Proteins 

• More 

What influences Mitochondiral form & functi

• division 

• fusion 

• motitility 

• tethering

and the interaction/contacts that the mitochondria has with other organelles within the cell 

Mitochondrial DNA (MtDNA)

• DNA specific to the mitochondria

• only comes from my mom, dad’s is destroyed in most organism 

• contains less genes than nuclear DNA but is more abundant in the cell 

The importance of mitochondria in the evolution of eukaryotic cells

Mitochondria allowed for more energy expenditure and in turn the creation of more complex organisms. (We use our body weight of the ATP made by mitochondria per day)

Nucleus

• membrane that houses MOST of the DNA in a cell 

• has a DOUBLE MEMBRANE (2 lipid bilayers, 4 total) 

• has its own functional discrete functional domain like the nucleolus (site of rRNA & ribosome subunit assembly) 

Mitochondria

• enclosed by a double membrane

• Has it’s own genome (sign of prokaryotic ancestry) alongside the nuclear genome 

• has other functions than POWER 

Chloroplasts

• found in plant cells & photosynthetic algae

• Have a double membrane & internal membrane so (THREE MEMBRANES)

• sites of photosynthesis and carbon fixation

• have their own genome (sign of prokaryotic ancestry)

How chloroplasts came to be

early aerobic cell with mitochondria are a photosynthetic cell

Endoplasmic Reticulum

• tubular network 

• membrane is continuos with the outer nuclear membrane 

Functions of the ER (smooth)

• lipid synthesis 

Functions of Rough ER (the one with ribosomes on it)

• synthesis/processing of secreted membrane associated proteins 

Golgi Apparatus

• a stack of membrane enclosed compartments that function in modification, processing & sorting of proteins & lipids

Peroxisome

organelle that oxidizes toxic molecules

Lysosome

organelle that deals with the garbage

Kamala

think of the context that Mitochondria exists in, it doesnt just fall out of a cocount tree, it interacts and CONTACTS other organelle, influcneign it’s form & function.