Test 3 Flashcards
Complex I can leak what ____ toward the matrix?
O2
Complex III generates O2 where?
toward both matrix and inter-membrane space
When the cell is stressed it has what moved into the mitochondria.
apoptotic pathways, P66^she
P66 ^she is part of apoptosis generating _____ molecules.
ROS
How does P66^she accomplish apoptosis.
it accomplishes this by subtracting electrons from cytochrome c to produce O2
____ is highly regulated event in a cell. preventing apotosis.
ROS production
In a cell that has not signaled apoptosis O2 is dismutated to ____
H2O2
what dismutated H2O2
Cu, Zn, SOD (Super-oxide dismutatse)
What happens in the mitochondria after O2 is reduced to H2O2.
it is reduced to H2O by glutathione peroxidase (GPX) using GSH (glutathione), and the resultant oxidized glutathione (GSSG) is reduced back to GSH by glutathione reductase
A typical mammalian liver mitochondria has roughly ______ copies of the ATP synthase
15,000
Homologous versions of the ATP synthase are found?
plasma membrane of aerobic, bacteria, the thylakoid membrane of plant chloroplasts, and the inner mt membrane
Recent high-resolution EM work suggests that the two portions of the ATP synthase are connected by___
central peripheral stalk
ATP synthesizing enzyme has what two parts
F1 head, F0 (Fnot) basal section
F1
a spherical head
F0 (Fnot)
a basal section embedded in the inner membrane
The generated proton gradient is then used to make ATP via a protein complex known by several names
Fnot/F1 complex, ATP synthase, complex V (out of date)
Endergonic process is driven by ______ in energy level of the electron as it passes through.
reduction
what two enzymes are not part of the four complexes?
cytochrome c, ubiquinone (CoQ)
enzymes that transfer pairs of electrons from substrates to molecules such as the conenzymes NAD+ and FADH are called
dehydrogenases
Pathway by which monosaccharides are broken down
glycolysis
name an example of a monosaccharide in glycolysis
glucose
where does glycolysis occur
cytosol of eukaryotic cells and in prokaryotes
what three important molecules are generated during glycolysis
2ATP, 2pyruvate, 2NADH
The cyclic pathway that occurs in the matrix of mitochondrion
tricarboxilic acid cycle(TCA), citric acid cycle, krebs cycle,
What is a sybstrate for TCA
acetyl CoA
How is acetyl CoA formed?
via B-oxidation pathway in the mitochondrial matrix and in the peroxisome
by the transition reaction as pyruvate crosses the mitochondrial membranes generates?
1 NADH and releases 1 CO2
3 important molecules formed during TCA
2 ATP, 6 NADH, 2 FADH2, (2 CO2 are formed)
The high-energy electrons associated with NADH and FADH2 are transferred (dumped) to a series of specific electron carriers that constitute the ______ located in the inner mitochondrial membrane
ETC(Electron Transport Chain)
Lowest energy electrons are ultimately passed to molecular oxygen from ____
Complex IV
These protein complexes will use energy from the elections to establish a _____
H+ gradient withing the inter membrane space
The stored H+ gradient will power the endergonic process of synthesizing ATP via secondary or indirect active transport by the _____
F0/F1 complex
The ___ ETC complexes are composed of _____ types of membrane-bound electron carrier proteins
4,5
a polypeptide bound tightly to one of two related prosthetic groups
flavoproteins
proteins that contain heme prosthetic groups
cytochromes
both groups are derived from riboflavin (vitamin B2)
Flavin Adenine Dinucleotide (FAD) or Flavin Mononucleotide (FMN)
copper attoms are all located within ___
complex IV
Copper atoms alternate between
Cu^2+, Cu+1
lipid-soluble molecule containing a long hydrophobic chain composed of 5-carbon isoprenoid units
ubiquinone
ubiquinone is able to accept ____ electrons and protons
2
Where does ubiquinone reside
lipid bi-layer and moves about freely
contain iron not in a heme group, but that is instead linked to inorganic sulfur atoms
iron sulfur
iron- sulfur donates ___ electrons
single
Glycolisis makes
net gain 2 ATP, 2 pyruvate, 2 NADH
TCA cycle, citric acid cycle, and Krebs cycle
2 ATP 6 NADH, 2CO2
What is the pathway by which monosaccharides (such as glucose) are broken down
glycolysis
Where does glycolysis occur
cytosol of eukaryotic cells and in prokaryotes
enzymes that transfer pairs of electrons from substrates to molecules such as the coenzymes NAD+ and FADH (empty wheelbarrows)
dehydrogenases
The pathways of glycolyisis and TCA are rich in _____ some termed dehydrogenases
proteins
Solution withing inner membrane of the mitochondria is termed
matrix
what is the sight of the TCA pathway
matrix
Where does the mitochondrial gene expression and genome replication occur
matrix
the infoldings of membrane in the mitochondria are termed_____
cristae
The space between membranes in the mitochondria is termed the ________
intermembrane space
mitochondria is _____ part of the endomembrane system
not
mitochondria are ______, meaning they grow and divide within the cell and generate some of the proteins that function there, and take up others from the cytoplasm
semiautonomous
Mitochondria have there own
DNA and ribosomes
mitochondria are about ____ in diameter
1-10um
Glucose moves across the apical plasma membrane against a concentration gradient by
Na+ contransport (symport)
The needed Na+ gradient is maintained by _____ by the Na+/K+ -ATPase pump in the basal and lateral membranes of the cells
active transport
Finally the glucose molecules move into the blood stream by ____ _____ through a glucose transporter (glucose permease)
facilitated diffusion
Tums and Rolaids work by neutralizing
acid (H+) in the stomach
Zantac, Pepcid, and Tagamet work instead by
blocking receptors on the surface
Over secretion of acid can lead to _______
heartburn
The epithelial lining of the stomach contains a _____ which secreetes a solution of concentrated acid (up to 0.16 NHCL) into the stomach chamber
H+/K+ -ATP
In the resting state of transport proteins are situated in the membranes of
cytosolic vesicles
When food enters the stomach a hormonal message is transmitted to the parietal cell causing the ______ vesicles to move to the ______ cell surface and begin secreting acid.
pump-containing, apical
an example binds at a cell surface receptor triggering cellular signal transduction
histamine
Driving exergonic reaction here is the use of the Na+ is present to bind simultaneously
sodium-glucose symport
Cells lining our intestine are able to take up molecules like glucose or amino acids from the lumen into the cells even when the cellular concentration is higher than the lumen concentration
sodium-glucose symport
The subsequent facilitated diffusion of Na+ back across the membrane drives the intake of glucose, and other molecules this is termed
indirect active transport or secondary active transport
what pump is found only in animals, although other species accomplish the same tasks with analogous mechanisms and proteins
sodium-potassium pump
the sodium -potassium pump has a ____ ____ for Na+ with binding sites oriented towards the cytoplasm
high affinity
The sodium-potassium pump has a high affinity for ____ with binding sites oriented towards the cell’s exterior.
K+
termed ____ ___ in nonexciteable cells (those other than neurons and muscle)
membrane potential
termed a _____ _____ in neurons and muscle cells
resting potential
Such _____ movement ofions requires being coupled to an _____ reaction such as
endergonic, exergonic
____ depends on integral membrane proteins that selectvely bind a particular solute and move it across the membrane against its concentration gradient in a process driven by energy requiring changes in the protein’s conformation.
active transport
proteins that carry out active transport are often referred to as ____
pumps
very similar to facilitated diffusion but it moves molecules against a concentration gradient and therefore, requires an energy input
active transport
Typically the K+ concentration inside a mammalian is ___
higher
