Ch 3: Aerobic Respiration and the Mitochondria Flashcards
How do mitochondria reproduce?
can fuse with one another or split in two(fission). It arises from preexisting mitrochondria.
describe a mitochondrial structure
Mitochondria are seen as elongated, dark bodies. or a highly branched，interconnected tubular network.
The outer boundary contains two membranes(outer mitochondrial m. and inner mitochondrial m.)
The interior of the organelle contains a series of double-layered membranous sheets，called cristae
Compartment interior to mito is called matrix
What is the function of mitochondrial cristae?
The cristae contain a large amount of membrane surface which houses the machinery needed for aerobic respiration and ATP formation
What are the main difference between mitochondrial outer membrane and inner membrane?
the outer membrane is composed of approximately 50 percent lipid &; mixture of enzyme (cell wall of bacterial cells)
The inner membrane is 100 different polypeptides 3:1 protein lipid ratio rich in unusual phospholipid，cardiolipin. (bacterial plasma membranes.)
Which kind of phospholipids is specially located in the membrane of mitochondria?
cardiolipin
- Where do membrane proteins－porins exist in mitochondria? And in which kingdom do porins also exist?
In the Outer Mitochondrial Membrane and they exist in outer bacterial membranes i.e kingdom Bacteria
What is the difference of the permeability of mitochondrial outer membrane and inner membrane and what is the meaning of this difference?
The outer mitochondrial membrane and outer bacterial membrane both contains porins, integral proteins that have a relatively large internal channel（e.g. 2-3nm）surrounded by a barrel of β strands. While the inner mitochondrial membrane is highly impermeable, all molecules and ions require special membrane transporters to gain entrance to the matrix
How many copy of double stranded ring like DNAs do exist in matrix of mitochondria?
37
How many mitochondrial polypeptides does a ring like mitochondrial DNA encode?
13 in human
Where does glycolysis happen?
Cytosol
What are the final products of glycolysis and which one can be transported across mitochondrial inner membrane?
pyruvate and NADH. Each pyruvate molecule produced by glycolysis is transported across the inner mitochondrial membrane and into the matrix
Which product was fed into TCA cycle in the matrix of mitochondria?
Acetyl CoA
What is the ultimate product and also the initiate substrate of TCA?
Oxaloacetate
What metabolic pathway do all of a cell’s energy-providing macromolecules go into at last?
They are broken down into metabolites of the TCA cycle and mitochondrion becomes the focus for the final energy-conserving steps in metabolism regardless of the nature of the starting material.
During the TCA cycle, how many pairs of electrons are transferred from to electron-accepting coenzymes?
4 pairs of electron
How do NADH (formed in the cytosol during glycolysis) were fed into the mitochondrial electron transport chain?
①enter the mitochondrion（by a pathway called the malate-aspartate shuttle）and reduce NAD+ to NADH. OR
[2] transfer its electrons to FAD（by a pathway called the glycerol phosphate shuttle）to produce FADH2
Where do electron-transport chain locate inside mitochondria?
located in the inner mitochondrial membrane
Through which two steps are electron-accepting coenzymes used to produce ATP?
①high-energy electrons are passed from FADH2 or NADH to a series of electron carriers that make up the electron-transport chain，which is located in the inner mitochondrial membrane; electrons pass along the respiratory chain in energy-releasing reactions
②the controlled movement of protons back across the membrane through an ATP-synthesizing enzyme provides the energy required to phosphorylate ADP to ATP
How many ATP are released when one molecular NADH goes through electron-transport chain? and how about one molecular FADH2?
3 & 2 ATPs
How many ATPs are formed if one molecule of glucose completely catabolized by means of glycolysis and the TCA cycle?
36 ATPs
. What is the usage of endogenous uncoupling proteins（UCPs）?
a source of heat production,determining a person’s basal metabolic rate, which may help explain the physiological basis of obesity.
What is the resemblance of mitochondria with peroxisomes?
Both mitochondria and peroxisomes form by splitting from preexisting organelles；
Both import preformed proteins from the cytosol
both engage in similar types of oxidative metabolism
Which cell organelle is the site of synthesis and degradation of hydrogen peroxide?
Peroxisomes
MCQ
Mitochondrial genes ?
the ATP get from TCA cycle is?
22 tRnas, 2 rRnas, 13 polypeptides
the ATP get from TCA cycle is 24 ATP
