Cytoplasmic Organelles Flashcards
Where does much of the energy generating metabolism occur in the cell?
Mitochondria, chloroplasts, and peroxisomes
What feature of mitochondria and chloroplasts have which allows them to encode their own genes?
They carry their own DNA
What feature of mitochondria and chloroplasts have which allows them to make some of their own proteins?
They carry their own ribosomes
How do mitochondria, chloroplasts, and peroxisomes divide?
Autonomously; binary fission
What does the endosymbiont hypothesis explain?
Explains the origins of eukaryotes from prokaryotes
What evidence backs up the endosymbiont hypothesis?
Mitochondria and chloroplasts:
- Have circular DNA
- Have inner membranes with prokaryote properties
- Have 70S ribosomes
- Have unique protein import mechanisms
- Divide by binary fission
- If chloroplasts are depleted from a cell, they cannot reform
What are mitochondria developed from?
Proteobacteria
What are chloroplasts developed from?
Cyanobacteria
Where are the proteins translated in the post-translational pathway?
On free ribosomes in the cytosol
What molecule helps the transport of proteins through organelle membranes?
Chaperonins
How many mitochondria are found in a cell?
20 - >1000 /cell
What is the name of the protein that forms the small pores found in the outer membrane of a mitochondrion?
Perforin
What size of molecules can diffuse through the pores in the mitochondria’s outer membrane?
Less than 10kDa
What do the integral proteins found in the mitochondria’s inner membrane do?
Principally required for transport and processes that lead to ATP production
What will you find in a mitochondrion’s matrix?
- Molecules that have been specifically transported across the membrane, or have been generated by the mitochondrion’s own DNA
- Mitochondrial DNA, RNA, ribosomes
- Enzymes for the Kreb’s cycle
- Small granules
