ETC, ATP Synthesis, & Amino Acid Structure Flashcards
Where is the electron transport chain located?
inner mitochondrial membrane
What does the ETC do?
uses electrons from NADH and FADH2 produced by glycolysis, pyruvate dehydrogenase, and citric acid cycle for the production of ATP and then it regenerates FAD and NAD+ under aerobic conditions
Oxygen is the final electron acceptor in ?
ETC
Which each transfer of electrons, they get transfered to a ______ energy state
lower
energy released by electrons generates?
electrochemical gradient (H+ gradient)
Oxidized
loss electron
Reduced
gain electron
Reduction potential
affinity for electrons
Low reduction potential means
low affinity for electrons
Electrons are being transferred from molecules of ______ potential to _____
low to high
T/F: electrons acceptors are more negative
false; acceptors are more positive
Chemiosmotic Coupling
coupling between membrane transport and chemical bond formation (Mitochondrial matrix to intermembrane space)
Give an example of chemiosmotic coupling involving the ETC and ATP Synthase
Electron transport drives pump that pumps protons across membrane, proton gradient is then harnessed by ATP Synthase to make ATP
Electrochemical gradient provides energy for?
ATP Synthesis
ETC is made up of ____ complexes and _____ proton pumps
4;3
What are the two mobile electrons carriers in the ETC?
Q and Cytochrome C
Complex 1 allows _____ to enter
NADH
If it starts with NADH what complexes will it move through and how many protons will move to the intermembrane space?
1, 3, & 4; 10 protons
How many ATP are produced per NADH that enters the ETC?
3
Where does FADH2 enter? and pumps how many protons across the membrane?
complex 2; 6
How many ATP are produced per FADH2?
2
List the electron carriers that move electrons between complexes
Ubiquinone, Cytochromes, Iron-Sulfur Centers
Ubiquinone
carriers two electrons at a time; small and hydrophobic
Carriers electrons from complex 1 to complex 3 and complex 2 to complex 3
ubiquinone
Cytochromes contain what group?
Contains heme group (porphyrin ring with Fe bound)
How many electrons do cytochromes carry at a time?
1
Iron-Sulfur centers
1 electron center
Cytochrome C transports electrons from complex ___ to ____
3 to 4
Complex 1 AKA
NADH dehydrogenase
Complex 1
Donor: NADH Acceptor: Ubiquinone4 Protons pumped into intermembrane space per electron pair
Complex 2 AKA
Succinate Dehydrogenase
Complex 2
FADH2 oxidized to FADno proton pumpingDonor: FADH2Acceptor: Ubiquinone
Complex 3 AKA
Cytochrome b-c1 complex
Complex 3
pumps 4H+ across membrane acceptor: cytochrome CDonor: ubiquinone Electrons are passed from QH2 to cyctochrome C1 via electron
For every pair of electrons that come from ubiquinone we end up having ____ cytochrome C
2
Complex 4 AKA
Cytochrome oxidase
Complex 4
final redox reaction in ETCacceptor: oxygen output: 2 H20cytochrome C1 brings electrons in one at a time
T/F: Pumping of protons is endergonic and the discharge of the gradient is exergonic
True
For 1 NADH we get ___ ATP
3
For 1 FADH2 we get ___ ATP
2
ATP Synthase has ___ parts
Two; F1 & FO
F0 in ATP Synthase
in the membrane
F1 in ATP Synthase
peripheral membrane protein, plugs FO so proton gradient can form (really occurs)
F1 Complex
Alternating alpha and beta subunits. Gamma subunit is the central section
Each ___ subunit has a different conformation and a different ability to bind ADP/ATP
beta
Where does reactions occur?
beta subunit
What drives ATP Synthesis?
rotational catalysis
What are the three subunits?
empty–ready to accept ADP (phosphate)ADPATP
Gamma subunits rotate in which direction as protons are pumped across
counter clockwise
Contransport of what is required for ATP Synthesis?
H+ and phosphate
What drives the exchange of ADP for ATP due to an electrochemical gradient?
voltage difference
The net yield from glucose is?
36 ATP
NADH from glycolysis results in a lower/higher ATP yield than other NADH
lower
If complex 2 is not functioning, how much less ATP would be produced per glucose?
4 fewer
Excess sugar is stored as
glycogen
Storage of glycogen is primarily in the:
liver and muscle
Where does the breakdown of fatty acids occur?
Mitochondria
Each round of fatty-acid oxidation cycle releases:
1 acetyl-CoA1 NADH1 FADH2
How many ATP would be produced as a result of one cycle of fatty acid oxidation (not taking into account of the citric acid cycle)?
5
Where is Acetyl-CoA derived from?
breakdown of carbohydrates and fats feeds into the citric acid cycle
Glycolysis and Cancer
Glycolysis goes faster than normal because there is a limited O2 supplythe cells take up more glucose than normal cells due to more transporterscompounds that inhibit steps of glycolysis are often used in treatment
Glycolysis and Type 1 Diabetes
too few beta cells in the pancreas cause low insulin levels, leading to insufficient uptake of glucose by cells. can lead to lowered blood pH due to products of fatty acid oxidation
lowered blood pH
Ketoacidosis
Glycolysis and Type 2 Diabetes
development of insulin resistance- more insulin is required to achieve the same effects
When are ketone bodies produced?
prolonged fast or starvation (glucose is unavailable, glycogen deplettion, and gluconegenesis occurs)
Gluconeogenesis
glucose synthesis, uses acetoacetate to try to make glucose.
Ketone bodies function as
acids, which makes blood more acidic
When we dont have glucose for a long period of time… our bodies try to make
glucose
What are the levels of protein structure?
Primary, Secondary, Teritary, Quaternary
Primary structure is
the sequence of amino acids
Amino acids have its central carbon bonded to what and how
covalently bonded to 4 groups
how many different amino acids are there?
20
Amino group
H2N
Carboxyl Group
COOH
Amino Acid structure rubric
H2N–CHR–COOH
What are the four families of amino acids?
Basic Positive, Acidic Negative, Uncharged Polar and Nonpolar
How are amino acids linked to eachother?
via condensation reactions that result in the formation of peptide bonds
Are peptide bonds planar?
Yes
T/F: Peptide bonds have a partial double bond character, allowing rotation.
False. The partial double bond character prevents rotation.
conformation:
shape of a folded protein
proteins try to fold in a way that minimizes/maximizes free energy
minimizes
What type of bonds give proteins its shape?
noncovalent
Why are nonpolar (hydrophobic) R groups forced together?
to minimize interference with H-bonding between water molecules
Cellular Respiration: List 3 stage
- Generation of Acetyl-CoA2. Citric Acid Cycle3. ETC
secondary structure:
stretches of a protein that forms alpha helices and beta sheets
alpha helix
polypetitide chain twists to form a cylindersecondary structure
alpha helices occur ____amino acids/turn
3.6
amino groups forms a H-bond with the carboxyl group at the _____ position
n+4
each strand of a beta sheet has a pleat ever ____ amino acids
2
What are the two subtypes of beta sheets?
Antiparallel & parallel
tertiary structure
3D arrangement of secondary elements connected by loops
what stablizes tertiary structure?
noncovalent interactions and disulfide bonds
Amino Acid Location: Nonpolar tends to be _______
interior
Amino Acid Location: Polar charged tend to be on the ______
surface
Amino Acid Location: Polar uncharged tend to be ______
found on the interior and on the surface
What are the two classes of tertiary structure?
Fibrous and Globular
Fibrous Proteins
polypeptide chains composed primarly of one type of secondary structure
Fibrous Proteins provide
strength and stability
T/F: Fibrous proteins are not insoluble in water due to the large number of hydrophobic amino acids
False. They are insoluble.
Examples of Fibrous Proteins
Keratin, Fibroin & Collagen
Globular Proteins
Polypeptide folds into a compact shape with an irregular surface (Mix of secondary structural elements)
Are globular proteins water soluble?
Yes.
What are Globular proteins made up of?
Motifs and Domain
Motif
pattern or arrangment of secondary structure that has been seen multiple times
Domain
a strech of amino acids that are capable of folding independently of the rest of the polypeptide into a compact and stable structure
What is an example of Globular Protein?
Src (enzyme with three domains)
Protein Folding Chaperones
molecular chaperones bind partially folded polypeptides to help them fold, they minimize energy used for the folding process and prevent inappropiate association of unfolded proteins
Two types of Chaperones
Hsp70 & Hsp60
Hsp70
smaller, fold as translated, protein still attached to ribosome, energy needed
Hsp60
larger, occurs after translation, released from ribosome
Disulfide Bonds
covalent bonds that crosslink parts of a chain or two different chains via adjacent cysteine side chains
What do disulfide bonds stabilize?
tertiary and quarternary protein structure
Protein Disulfide Isomerase (PDI)
binds to unfolded/incorrectly folded proteins to allow new bonds to be formed until the correct bonds are formed
Give an example of a protein that needs to be cleaved to be functional?
Insulin
What type of protein is more likely to function as an enzyme?
Globular
Quarternary Structure
protein composed of multiple polypeptides, subunits can be identical or different
What is quarternary structure stabilized by?
noncovalent interactions and disulfide bonds
can subunits of quarternary structure be differeent?
Yes
Alzheimers Disease results in part to
problems in protein folding
if a misfolded protein is present, it causes the normally folded protein to misfold leading to
disease (the brain develops holes)
