Eukaryotic cells Flashcards
What do Eukayotes have are differ to prokaryotes?
Have membrane enclosed organelles .
Each organelle membrane also has a mechanism for importing /incorporating into organelles
Specific proteins make organelle unique
Eukaryotic cells are divided into sub compartments or organelle
Which each organelle has a specific function with characteristic proteins and enzymes that carry out specific functions
What are the functions of the organelle ?
Ribosomes- Synthesis proteins
Golgi apparatus - Modify proteins , adding lipids
Chloroplasts - /Mitochondria- generate ATP
Lysosomes- degrade intracellular organelles and particles up taken from outside the cells
Endosomes- Uptake material from outside of the cells
Peroxisomes- Are the compartment implicated in oxidative reactions
What is the role of the Protein ? How does protein synthesis occur ?
Happens in the ribosomes
Proteins leave the ribosomes and reach the organelles
Proteins are translated by ribosomes according to genetic information carried by mRNA.
Ribosomes are organelles that are not membrane enclosed synthesis both soluble and integral proteins .
What about Mitochondria and plastids differ ?
From the other membrane enclosed organelle because they contain their own genome
Key challenges - Topological challenge
Ribosomes only on cystolic face , nascent newly synthesised , proteins must cross membrane at least in part
Specificity Challenge
Proteins must reach correct destination , without scrambling the content of different compartments
Topological challenge ?
Inside lumen of endomembrane systems topologically equivalent to extracellular space
Lumen of the eR is topologically equivalent to the lumen of other endomembrane organelle /extracellular space
Equivalent compartments in secretary and endocytic pathways in a eukaryotic cell
Equivalent if they communicate with another , in the sense in which molecules can get one to other without having to cross a membrane
Some organelles such as mitochondria plastids do not take part in this communication /isolated from vesicular traffic between organelles.
What is the role of specificity challenge?
Each protein must reach the right organelle
With each organelle having a specific function with characteristic proteins and enzymes carry out specific reactions
What are the only two sites of protein synthesis ?
Cytosol and rough endoplasmic reticulum
The rough endoplasmic has many ribosomes bound to its cystolic space
