Lecture 6 (Aerobic Respiration & Mitochondria) Flashcards
What are Anaerobes?
Anaerobes capture and use energy without Oxygen molecules in metabolism
What are Aerobes?
Aerobes use oxygen to extract more energy from metabolism
What are 3 important facts about mitochondria?
They’re a specialized organelle that uses oxygen for energy extraction
Were evolved from bacteria
Have their own genome and proteins synthesize mechanisms
True or False?
Different cell types can have very different mitochondria structure?
True !!!
True or False?
The size or number of mitochondria in the cell do not reflect the energy requirements in the cel
False !!!
The size or number DO reflect the energy requirements of the cell
True or false?
Mitochondria cannot fuse together but can split into two
False !!!
Mitochondria can both fuse together and split a part
What initiates the fission (splitting) of mitochondria?
What completes the fission?
the ER (endoplasmic reticulum) initiates the fission while recruited soluble proteins complete the fission
What type of droplets provide mitochondria with raw materials for ATP production?
Fatty acids
What are some other important produced substances mitochondria make?
Certain amino acids and heme groups
What do mitochondria release and uptake inside of cells that’s important for activities?
Calcium Ions
What is the general structure of mitochondrial membranes?
An outer and inner membrane
the Inner membrane has two major domains called the inner boundary domain and outer domain
what resides in the inner boundary membrane domain? what is it’s purpose?
a large amount of proteins to import mitochondrial proteins
What is the composition of the outer domain?
a series of sheets called cristae
What does the Cristae house?
The Cristae has all the components needed to produce ATP formation and aerobic respiration
What are the 2 membranes of mitochodria and where are they located?
The Matrix - within the interior
Intermembrane Space - between the outer and inner membrane
What are the 2 things contained in the Mitochondrial Matrix?
Ribosomes
Several molecules of circular DNA for RNA and protein production
What is the composition of ATP? What is the process of releasing energy?
an Adenine
an Ribose
3 phosphate groups (Alpha, Beta, Gamma)
Dephosphorylation
what is phosphorylation and what does it require?
the addition of a phosphate group to AMP and ADP
it requires energy
What is the function of electron carriers?
Bind high and carry high energy electrons between compounds
What is Oxidation? What is Reduction?
Oxidation removes electrons from a molecule
Reduction adds electrons to a molecule
What is Glycolysis?
The first pathway to breaking down glucose for energy
What occurs in Glycolysis?
the Glucose 6 carbon ring is split in (2) 3-carbon rings.
2 ATP is used and 4 ATP is gained
What is Fermentation and when does it occur?
an alternative process in which the product of glycolysis is used to regenerate NAD+. Occurs when there’s an insufficient oxygen supply
What is the TCA?
A Cycle in which the product of glycolysis is converted to a 2 carbon chain, then combined with a 4 carbon chain to form citrate, which is then oxidized to 2 CO2 and a the 4 carbon chain which is then reused.
This creates FADH2 and NADH which is then used to form ATP
What is the process of ATP formation from FADH2 and NADH?
high energy electrons are passed from FADH2 and NADH to electron carriers of the Electron Transport Chain
Causes the movement of Protons (H+) back into the cell
3 ATP formed for NADH and 2 ATP for FADH
What is the definition of Oxidative phosphorylation?
When ATP formation is driven by energy released from electron removal
What is the difference between strong oxidizing and strong reducing agents?
Strong oxidizing has a high affinity for electrons
Strong reducing has a weak affinity for electrons
What is the electron donor at complex 1 and 2?
NADH complex 1
FADH complex 2
What is a Flavoprotein? what is an example?
Polypeptides bound to FAD or Flavin
NADH
What is a Cytochrome?
Electron carrier with heme-groups of Fe or Cu metals
Changes in oxidative states results in accepting or loss or electrons
What are Three cooper atoms?
A single protein complex that alternates between Cu2+ and Cu3+
What are Ubiquinone?
lipid-soluble molecule made of 5 Carbon units
What are Iron-Sulfur Proteins?
linked to proteins at cysteine residues
How do the Electron Carriers interact with one another in the Electron Transport Complexes?
Each carrier is reduced by the previous and oxidized by the one following
What is the Final electron accepter of the Electron Transport Chain?
O2, which is reduced to water
What does complex 1 do?
Catalyzes the transfer of electrons from NADH
What does complex 2 do? What prevents radicals from forming?
feeds lower energy electrons from FAD
Heme group prevents radicals from forming by attracting escaped electrons
What does complex 3 do?
Further catalyzes the transfer of electrons
What does Complex 4 do?
Catalyze O2 reduction. each O2 reduced causes 4 protons (H+) to make water and 4 protons (H+) to move into the membrane
What does the proton gradient cause?
a pH different or gradient between the inside and outside of the cell
A separation of charge across the membrane (electric potential)
Describe the origin, structure, and functions of the membranes and
matrix of the mitochondrion.
▪ Outline the function of glycolysis, fermentation, the TCA cycle and
oxidative phosphorylation.
▪ Explain how the transport of electrons down the respiratory chain leads
to the formation of a proton gradient.
▪ Explain how translocation of protons can establish a proton-motive
force.
