Unit 1 (Chapter 4, Part 5) Semiautonomous Organelles Flashcards
What is a mitochondrion?
Plural, mitochondria.
A semiautonomous organelle found in eukaryotic cells that supplies most of a cell’s ATP.
Similiar in size to bacteria. Muscle cells, because of the energy demand, have many more of these.
Research has shown that regular exercise increases the number and size of mitochondria in human muscle cells to meet the demand for energy.
What does the intermembrane space consist of in mitochondria?
The outer and inner membrane space.
Since the inner membrane is invaginated (folded), what are the projections it forms?
Cristae.
These folds and the cristae projections greatly increase the surface area of the inner membrane, which is where ATP is made.
What is the compartment inside the membrane where ATP is synthesized?
Mitochondrial matrix.
What is the advantage of the mitochondrion’s highly invaginated inner membrane?
The invaginations increase the surface area where ATP synthesis takes place, thereby increasing the amount of ATP synthesis. THIS IS THE PRIMARY ROLE.
Their actual role is the conversion of chemical energy (covalent bonds) into a form that is readily used by cells (ATP).
What is another interesting role of mitochondria? Think bears.
They generate heat in specialized fat cells known as brown fat cells. These groups of cells serve as heating pads that help to revive hibernating animals and protect sensitive areas of young animals from the cold.
What is a semiautonomous organelle found in plant and algal cells that carries out photosynthesis?
Chloroplasts
What is the process whereby light energy is captured by plant, algal, or photosynthetic bacterial cells and is used to synthesize organic molecules from CO2 and H2O (or H2S)?
Photosynthesis
Since chloroplasts contain two membranes as well, what does the third membrane?
The third membrane (not a full layer just the layer of the component within the second membrane), called the thylakoid membrane, within the chloroplast that forms many flattened, fluid-filled tubules that enclose a single, convoluted compartment. It contains chlorophyll and is the site where the light-dependent reactions of photosynthesis occurs.
What do you call the structure composed of stacked membrane-bound thylakoids within a chloroplast?
Granum
What do you call the fluid filled region of the chloroplast between the thylakoid membrane and the inner membrane?
Stroma
What is the general name given to organelles found in plant and algal cells that are bound by two or more membranes and contain DNA and large amounts of either chlorophyll (in chloroplasts), carotenoids (in chromoplasts), or starch (in amyloplasts)?
Plastids.
These are distinguished by their abilities and types of pigment they have. For example, chloroplasts carry out photosynthesis and have the green pigment called chlorophyll.
Chromoplasts, a second type of plastid, function in synthesizing and storing yellow, orange, and red pigments known as carotenoids. Gives many fruits and flowers their colors.
Leucoplasts, typically lacks pigment molecules.
Amyloplast is a leucoplast that synthesizes and stores starch. Common in underground plant structures like roots.
What are proplastids?
A type of unspecialized structure from which a plastid is derived.
What are mitochondrial and chloroplast genomes?
Chromosomes found within the mitochondria and chloroplasts. Very small, single, circular chromosome (like bacteria).
Nuclear genome is the chromosomes found in the nucleus of a eukaryotic cell.
Typical DNA in the human genome is about 3 billion base pairs which is 200,000 times bigger than the genome within the mitochondrial genome. 22,000 encoding genes versus 12. Chloroplasts are typically 10 times the size of mitochondrial genomes in humans.
What is the striking resemblance that mitochondrial and chloroplastic genomes have with bacterial genomes?
The process of cell division in bacteria and archaea in which one cell divides into two cells called binary fisson.
Fun Fact: Just like in human mitochondrial growth with exercise, the growth of chloroplast cells with more sunlight.
