Separation of DNA and cytoplasm by a nuclear envelope

Presense of MEMBRANE BOUND ORGANELLES.

Emergence of endomembrane system - infolding of the plasman membrane creating nuclear envelope as well as the endoplasmic reticulum

Theory of endosymbiosis - A prokaryotic cell gets some aerobic cells inside of it. The aerobic cells turn to mitochondria. Some of the mitochondria turn to chloroplasts -> Plants

What are some evidences supporting endosymbiosis?

1. Morphology - Bacteria kind of look like Mitochondria

2. Reproduction - A cell cannot synthesize mitochondria or chloroplasts - Only previous mitochondria and chloroplasts can synthesize other mitochondria and chloroplasts. They do this by BINARRY FISSION.

3. Genetic information - Mitochondria and Chloroplasts contain their own DNA which is CIRCULAR LIKE PROKARYOTES

4. Contain their own set of machinery for their own transcription and translation. Their ribosomes are similar to that of bacterial ribosomes.

5. Electron transport - They have their own ETC which is similar to prokaryotic ETC. In prokaryotes the ETC is in the plasma membrane but in mitochondria it's in the inner membrane (evidence of swallowed up membrane)

6. Ribosomal RNA sequences establish that mitochondria and chloroplasts belong in the bacterial tree of life.

Chloroplasts RNA similar to Cyanobacteria

Mitochondrial RNA similar to Proteobacteria

Bacterium usually have 3000 genes while mitochonria only have 37 genes - what happened to all the genes?

1. Some genes lost - Rendundant with the nucleus

2. Some genes are relocated to the nucleus (HGT)

- Centralized genetic info

- 90% of the needed genes to encode mitochondria and chloroplasts are in the nucleus

1. Gene transfer not complete yet

2. Retained genes encode for proteins involved in electron transport chain - Tight regulation may be hard if genes in nucleus

The Nucleus - List the properties of

Chromosomes

Chromatin

Nucleolus (and location)

Nuclear membrane

Pore complex

Chromosomes - Single DNA molecule with proteins

Chromatin - Non coiled version of chromosomes

Nucleolus - Where rRNA synthesize (middle of nucleus)

Nuclear membrane - Double membrane (outer and inner)

Pore complex - Regulates entry and exit of macromolecules, RNA, protein.

Ribosomes are _________

List the different types of ribosomes and their properties

Protein factories

Free ribosomes in cytosol

-> Proteins which function in the cystosol

Ribosomes bound to the ER

proteins destined for 

1. insertion in membranes

2. Packaging in organelles (e.g lysosomes)

3. Export from the cell (secretion)

What is the endoplasmic reticulum?

Interconnected network of membranous channels and vesicles called cisternae

What is the Rough ER?

What does the rough ER do?

The rough ER is ribosome studded membrane surfaces facing cytoplasm

Protein enter the lumen where they are chemically modified. They are then delivered to other regions of the cell via small vesicles.

Synthesizes lipids

Detoxifies drugs and poisons

Stores calcium ions

What does the golgi complex do?

Where do proteins enter and where do proteins exit the golgi complex?

Proteins enter from the cis face and exit from the trans face

The golgi complex modifies ER products

Modifies certain macromolecules

Sorts and packages proteins for transport

Look at lec 5's diagrams (cis golgi trans golgi slide in particular)

MEMORIZE THEM

What are lysosomes?

What do they do?

Lysosomes are membranous sacs of hydrolytic enzymes

They digest macromolecules (and other stuff)

They have an acidic PH

Also look at lec 5's phagocytosis slide

Where does cellular respireation occur?

Where does the ATP generating reaction occur?

Cellular respiration occurs in the mitochondria

ATP generation occurs in the cristae and matrix. (Sites inside the mitochondria)

Look at Lec 05's diagram of mitochondria