Podcast
Questions and Answers
What is a major activity of all cells?
What is a major activity of all cells?
The generation of metabolic energy.
What do mitochondria generate energy from?
What do mitochondria generate energy from?
The breakdown of lipids and carbohydrates.
What does the inner membrane of mitochondria have numerous folds called?
What does the inner membrane of mitochondria have numerous folds called?
Cristae
Where does glycolysis occur?
Where does glycolysis occur?
Signup and view all the answers
What is the name of the process that produces most of the cell's energy?
What is the name of the process that produces most of the cell's energy?
Signup and view all the answers
What do high-energy electrons from NADH and FADH2 transfer through?
What do high-energy electrons from NADH and FADH2 transfer through?
Signup and view all the answers
What is the property of the inner membrane that is critical to maintaining the proton gradient?
What is the property of the inner membrane that is critical to maintaining the proton gradient?
Signup and view all the answers
What forms channels that allow the free diffusion of small molecules?
What forms channels that allow the free diffusion of small molecules?
Signup and view all the answers
How do mitochondria often position themselves?
How do mitochondria often position themselves?
Signup and view all the answers
What process allows the exchange of genetic material in mitochondria?
What process allows the exchange of genetic material in mitochondria?
Signup and view all the answers
What is crucial for the distribution of mitochondria between daughter cells during cell division?
What is crucial for the distribution of mitochondria between daughter cells during cell division?
Signup and view all the answers
Mitochondria are thought to have evolved from bacteria living inside larger cells.
Mitochondria are thought to have evolved from bacteria living inside larger cells.
Signup and view all the answers
What type of bacteria have genomes similar to mitochondria?
What type of bacteria have genomes similar to mitochondria?
Signup and view all the answers
What is the intracellular parasite that can reproduce only within eukaryotic cells, like mitochondria?
What is the intracellular parasite that can reproduce only within eukaryotic cells, like mitochondria?
Signup and view all the answers
What type of DNA molecules are mitochondrial genomes typically?
What type of DNA molecules are mitochondrial genomes typically?
Signup and view all the answers
Besides oxidative phosphorylation, what else do mitochondrial genomes encode?
Besides oxidative phosphorylation, what else do mitochondrial genomes encode?
Signup and view all the answers
What does the human mitochondrial genome encode?
What does the human mitochondrial genome encode?
Signup and view all the answers
The mitochondrial genetic code is the same as the universal code.
The mitochondrial genetic code is the same as the universal code.
Signup and view all the answers
How many codons are recognized by a single tRNA in the mitochondrial genetic code?
How many codons are recognized by a single tRNA in the mitochondrial genetic code?
Signup and view all the answers
Mitochondrial DNA can be altered by mutations.
Mitochondrial DNA can be altered by mutations.
Signup and view all the answers
What are almost all the mitochondria of fertilized eggs contributed by?
What are almost all the mitochondria of fertilized eggs contributed by?
Signup and view all the answers
What disease is caused by mutations in mitochondrial genes that encode components of the electron transport chain?
What disease is caused by mutations in mitochondrial genes that encode components of the electron transport chain?
Signup and view all the answers
How many proteins do mammalian mitochondria genomes encode?
How many proteins do mammalian mitochondria genomes encode?
Signup and view all the answers
About how many different proteins encoded by the nuclear genome do mammalian mitochondria contain?
About how many different proteins encoded by the nuclear genome do mammalian mitochondria contain?
Signup and view all the answers
What are the proteins needed for replication and expression of mitochondrial DNA?
What are the proteins needed for replication and expression of mitochondrial DNA?
Signup and view all the answers
Which of the following are synthesized on free ribosomes and imported to mitochondria as complete polypeptides?
Which of the following are synthesized on free ribosomes and imported to mitochondria as complete polypeptides?
Signup and view all the answers
What are the amino-terminal sequences that are removed by proteolytic cleavage after import?
What are the amino-terminal sequences that are removed by proteolytic cleavage after import?
Signup and view all the answers
What is the name of the protein complex located on the outer mitochondrial membrane that serves as a receptor for presequences?
What is the name of the protein complex located on the outer mitochondrial membrane that serves as a receptor for presequences?
Signup and view all the answers
What is the complex located in the inner mitochondrial membrane that receives proteins after they are transported through the Tom complex?
What is the complex located in the inner mitochondrial membrane that receives proteins after they are transported through the Tom complex?
Signup and view all the answers
Protein translocation requires the electrochemical potential established across the inner mitochondrial membrane.
Protein translocation requires the electrochemical potential established across the inner mitochondrial membrane.
Signup and view all the answers
Proteins must be folded before being imported into mitochondria.
Proteins must be folded before being imported into mitochondria.
Signup and view all the answers
What cleaves presequences after import?
What cleaves presequences after import?
Signup and view all the answers
What binds to and assists in the folding of polypeptides after the presequence is cleaved?
What binds to and assists in the folding of polypeptides after the presequence is cleaved?
Signup and view all the answers
What happens to proteins with multiple transmembrane domains?
What happens to proteins with multiple transmembrane domains?
Signup and view all the answers
What do Tim9-Tim10 chaperones do in this scenario?
What do Tim9-Tim10 chaperones do in this scenario?
Signup and view all the answers
Some inner membrane proteins are encoded by the mitochondrial genome.
Some inner membrane proteins are encoded by the mitochondrial genome.
Signup and view all the answers
Where are these proteins synthesized?
Where are these proteins synthesized?
Signup and view all the answers
Where are these proteins targeted to?
Where are these proteins targeted to?
Signup and view all the answers
How do these proteins exit Oxa1 to insert into the inner membrane?
How do these proteins exit Oxa1 to insert into the inner membrane?
Signup and view all the answers
What do proteins destined for the outer membrane or intermembrane space pass through?
What do proteins destined for the outer membrane or intermembrane space pass through?
Signup and view all the answers
How are proteins with single transmembrane domains inserted into the outer membrane?
How are proteins with single transmembrane domains inserted into the outer membrane?
Signup and view all the answers
What is the name of the translocon that β-barrel proteins are carried to?
What is the name of the translocon that β-barrel proteins are carried to?
Signup and view all the answers
Lipids are imported from the cytosol into mitochondria.
Lipids are imported from the cytosol into mitochondria.
Signup and view all the answers
What phospholipid do mitochondria catalyze the synthesis of?
What phospholipid do mitochondria catalyze the synthesis of?
Signup and view all the answers
What does cardiolipin do to improve the efficiency of oxidative phosphorylation?
What does cardiolipin do to improve the efficiency of oxidative phosphorylation?
Signup and view all the answers
What mediates lipid transfer between the ER and mitochondria?
What mediates lipid transfer between the ER and mitochondria?
Signup and view all the answers
What energy source does the electrochemical gradient generated by proton pumping during oxidative phosphorylation provide?
What energy source does the electrochemical gradient generated by proton pumping during oxidative phosphorylation provide?
Signup and view all the answers
The transport of ATP and ADP across the mitochondrial inner membrane is mediated by an integral membrane protein called the adenine nucleotide translocator.
The transport of ATP and ADP across the mitochondrial inner membrane is mediated by an integral membrane protein called the adenine nucleotide translocator.
Signup and view all the answers
What is the exchange of one molecule of ATP for one molecule of ADP across the mitochondrial inner membrane driven by?
What is the exchange of one molecule of ATP for one molecule of ADP across the mitochondrial inner membrane driven by?
Signup and view all the answers
What is brought into mitochondria as phosphate in exchange for hydroxyl ions?
What is brought into mitochondria as phosphate in exchange for hydroxyl ions?
Signup and view all the answers
If you were to compare chloroplasts to mitochondria, how are they similar?
If you were to compare chloroplasts to mitochondria, how are they similar?
Signup and view all the answers
What is the primary difference in size and complexity between mitochondria and chloroplasts?
What is the primary difference in size and complexity between mitochondria and chloroplasts?
Signup and view all the answers
What do chloroplasts convert carbon dioxide to?
What do chloroplasts convert carbon dioxide to?
Signup and view all the answers
Chloroplasts contain their own DNA molecules.
Chloroplasts contain their own DNA molecules.
Signup and view all the answers
What is the name of the double membrane that surrounds chloroplasts?
What is the name of the double membrane that surrounds chloroplasts?
Signup and view all the answers
What does the thylakoid membrane form within chloroplasts?
What does the thylakoid membrane form within chloroplasts?
Signup and view all the answers
What are the three internal compartments of chloroplasts?
What are the three internal compartments of chloroplasts?
Signup and view all the answers
What is the inner membrane of chloroplasts impermeable to?
What is the inner membrane of chloroplasts impermeable to?
Signup and view all the answers
What does the stroma contain?
What does the stroma contain?
Signup and view all the answers
Where does electron transport and ATP generation take place in chloroplasts?
Where does electron transport and ATP generation take place in chloroplasts?
Signup and view all the answers
What are pumped across the thylakoid membrane during photosynthesis?
What are pumped across the thylakoid membrane during photosynthesis?
Signup and view all the answers
What is the thylakoid membrane equivalent to in mitochondria?
What is the thylakoid membrane equivalent to in mitochondria?
Signup and view all the answers
Chloroplast genomes are larger and more complex than those of mitochondria.
Chloroplast genomes are larger and more complex than those of mitochondria.
Signup and view all the answers
What do chloroplast genetic systems reflect?
What do chloroplast genetic systems reflect?
Signup and view all the answers
Chloroplast tRNAs are sufficient to translate all mRNA codons using the universal genetic code.
Chloroplast tRNAs are sufficient to translate all mRNA codons using the universal genetic code.
Signup and view all the answers
What enzyme does one subunit of rubisco is encoded by?
What enzyme does one subunit of rubisco is encoded by?
Signup and view all the answers
What is the name of the cycle where rubisco catalyzes the addition of CO2 to ribulose-1,5-bisphosphate?
What is the name of the cycle where rubisco catalyzes the addition of CO2 to ribulose-1,5-bisphosphate?
Signup and view all the answers
Rubisco is critical for photosynthesis.
Rubisco is critical for photosynthesis.
Signup and view all the answers
Where are other proteins synthesized and then imported into chloroplasts?
Where are other proteins synthesized and then imported into chloroplasts?
Signup and view all the answers
What are the N-terminal sequences that direct translocation across the two membranes of the envelope and are removed by proteolytic cleavage?
What are the N-terminal sequences that direct translocation across the two membranes of the envelope and are removed by proteolytic cleavage?
Signup and view all the answers
What does the Toc complex translocate?
What does the Toc complex translocate?
Signup and view all the answers
What keeps polypeptides in an unfolded state during import into chloroplasts?
What keeps polypeptides in an unfolded state during import into chloroplasts?
Signup and view all the answers
What do some Hsp70 molecules hydrolyze to provide energy during the translocation process?
What do some Hsp70 molecules hydrolyze to provide energy during the translocation process?
Signup and view all the answers
What complex do proteins enter on the inner chloroplast membrane?
What complex do proteins enter on the inner chloroplast membrane?
Signup and view all the answers
What does the Tic complex transport proteins to?
What does the Tic complex transport proteins to?
Signup and view all the answers
What cleaves the transit peptide in the stroma?
What cleaves the transit peptide in the stroma?
Signup and view all the answers
What do proteins that must cross the thylakoid membrane have?
What do proteins that must cross the thylakoid membrane have?
Signup and view all the answers
What are the two pathways that proteins can take to be translocated into the thylakoid lumen?
What are the two pathways that proteins can take to be translocated into the thylakoid lumen?
Signup and view all the answers
What does the Sec pathway require?
What does the Sec pathway require?
Signup and view all the answers
What pathway does the Tat pathway use to gain energy?
What pathway does the Tat pathway use to gain energy?
Signup and view all the answers
What does the Tat pathway allow proteins to be transported as?
What does the Tat pathway allow proteins to be transported as?
Signup and view all the answers
What cleaves the signal sequences in the Tat pathway?
What cleaves the signal sequences in the Tat pathway?
Signup and view all the answers
What do proteins with a transmembrane sequence exit the Sec translocon laterally?
What do proteins with a transmembrane sequence exit the Sec translocon laterally?
Signup and view all the answers
What recognizes proteins in the SRP pathway for chloroplasts and inserts them into the thylakoid membrane?
What recognizes proteins in the SRP pathway for chloroplasts and inserts them into the thylakoid membrane?
Signup and view all the answers
The insertion of proteins into the thylakoid membrane can occur by a mechanism that does not involve any known transport machinery.
The insertion of proteins into the thylakoid membrane can occur by a mechanism that does not involve any known transport machinery.
Signup and view all the answers
What are chloroplasts a type of?
What are chloroplasts a type of?
Signup and view all the answers
What do plastids share with chloroplasts but differ in?
What do plastids share with chloroplasts but differ in?
Signup and view all the answers
What are chloroplasts specialized for?
What are chloroplasts specialized for?
Signup and view all the answers
What are the other types of plastids involved in?
What are the other types of plastids involved in?
Signup and view all the answers
What is the name of plastids that contain carotenoids?
What is the name of plastids that contain carotenoids?
Signup and view all the answers
What are plastids that are nonpigmented called?
What are plastids that are nonpigmented called?
Signup and view all the answers
What do amyloplasts store?
What do amyloplasts store?
Signup and view all the answers
What do elaioplasts store?
What do elaioplasts store?
Signup and view all the answers
What do all plastids develop from?
What do all plastids develop from?
Signup and view all the answers
Mature plastids can change from one type to another.
Mature plastids can change from one type to another.
Signup and view all the answers
What do chromoplasts develop from?
What do chromoplasts develop from?
Signup and view all the answers
What are the single-membrane organelles containing enzymes involved in many metabolic reactions called?
What are the single-membrane organelles containing enzymes involved in many metabolic reactions called?
Signup and view all the answers
Peroxisomes have their own genomes.
Peroxisomes have their own genomes.
Signup and view all the answers
Where are most peroxisomal proteins synthesized?
Where are most peroxisomal proteins synthesized?
Signup and view all the answers
Peroxisomes can replicate by division but can also regenerate even if they're completely lost.
Peroxisomes can replicate by division but can also regenerate even if they're completely lost.
Signup and view all the answers
What are peroxisomal proteins typically?
What are peroxisomal proteins typically?
Signup and view all the answers
What kind of reactions do peroxisomes use to break down many substrates?
What kind of reactions do peroxisomes use to break down many substrates?
Signup and view all the answers
What converts hydrogen peroxide to water or oxidizes another organic compound?
What converts hydrogen peroxide to water or oxidizes another organic compound?
Signup and view all the answers
Peroxisomes are involved in the synthesis of lipids.
Peroxisomes are involved in the synthesis of lipids.
Signup and view all the answers
What are the phospholipids with one hydrocarbon chain joined to glycerol by an ether bond rather than an ester bond called?
What are the phospholipids with one hydrocarbon chain joined to glycerol by an ether bond rather than an ester bond called?
Signup and view all the answers
Where in animal cells are cholesterol and dolichol synthesized?
Where in animal cells are cholesterol and dolichol synthesized?
Signup and view all the answers
What are peroxisomes in the liver involved in the synthesis of?
What are peroxisomes in the liver involved in the synthesis of?
Signup and view all the answers
What is the name of the cycle that peroxisomes in seeds use to convert fatty acids into carbohydrates?
What is the name of the cycle that peroxisomes in seeds use to convert fatty acids into carbohydrates?
Signup and view all the answers
What is the name of the cycle that the glyoxylate cycle is a variant of?
What is the name of the cycle that the glyoxylate cycle is a variant of?
Signup and view all the answers
What does the glyoxylate cycle provide for the germinating plant?
What does the glyoxylate cycle provide for the germinating plant?
Signup and view all the answers
What are the peroxisomes sometimes referred to as?
What are the peroxisomes sometimes referred to as?
Signup and view all the answers
What are peroxisomes in leaves involved in?
What are peroxisomes in leaves involved in?
Signup and view all the answers