Chapter 7-PowerPoint Lectures Flashcards
How much do you multiply fat by to get calories?
9
How much do you multiply sugar by to get calories?
4
How much do you multiply protein by to get calories?
4
What is included in calories?
protein, fat, and sugar
Plants are autotrophs or heterotrophs?
autotrophs
How do autotrophs make food?
through sunlight and convert radiant energy into chemical energy
How do heterotrophs make food?
live off energy produced by autotrophs—-extract energy vis digestion and catabolism
What is cellular resperiaiton?
series of metabolic reactions that breakdown food and produce ATP
What are the two types of cellular respiration?
aerobic and anaerobic
Does aerobic respiration use oxygen?
yes
Which form of respiration uses oxygen as a reactant?
aerobic respiration
What is the goal of respiration?
produce ATP
What type of reactions does respiration use?
redox reactions
When is energy released in respiration? in what form?
oxidation reaction in the form of electrons
What type of respiration is it when oxygen is the final electron acceptor?
aerobic reaction
What type of respiration is it when oxygen is the final electron acceptor?
aerobic reaction
What is the empirical formula for glucose?
C6 H12 O6
How many ATP is made from one molecule of glucose?
32
Why can’t glucose reaction happen in one step?
delta G is really large, it would cause an explosion if that much free energy was released at once
What are the properties of electron carriers?
soluble, membrane-bound, move within membrane
Can all carriers be easily oxidized and reduced?
yes
What does NAD+ become when it accepts an electron?
NADH
What is dehydrogenase?
an enzyme that facilitates the transfer of electrons from a fuel molecule to an electron carrier
What is the structure of NAD+?
adenine, 2 ribose, 2 phosphates, nicotinamide
What three polymers of glucose ?
glycogen, cellulose, starch
What are the 4 stages of oxidation of glucose?
glycolysis, pyruvate oxidation, kreb’s cycle, electron transport chain and chemiosmosis (ATP production)
Where does glycolysis occur?
cytosol
Is there a loss of carbon in glycolysis?
no
What is used instead of oxygen in anaerobic respiration?
sulfate or nitrate
What is used instead of oxygen in anaerobic respiration?
sulfate or nitrate
What is an example of an electron carrier?
NAD+
What are electrons carried by and where are they carried to?
they are transported by electron carriers to the electron transport chain
Where is electron energy converted to ATP at?
electron transport chain
In aerobic respiration what is the final electron acceptor?
oxygen
In anaerobic respiration what is the final electron acceptor?
inorganic molecule other than oxygen
In fermentation what is the final electron acceptor?
organic molecule
In redox reactions where do electrons release some of their energy?
as they pass from a donor molecule to an acceptor molecule
What is the equation for ATP synthesis from glucose?
1 glucose + 6 O2 + 32 ADP + 32 Pi —> 6 H20 + 6CO2 + 32 ATP
What is the delta G for aerobic respiration of glucose?
-696 kcal/mol of glucose
Do all electron carriers carry just electrons?
No, some carry just electrons while some carry both electrons and protons
What is the name of NAD+?
nicotinamide adenine dinucleotide
In cellular respiration how many electron and protons are transferred to NAD+? and by what? What does this from?
dehydrogenases transfer 2 electrons and 1 proton which created
NADH
Where does pyruvate oxidation occur?
mitochondrial matrix
Where does kreb’s cycle occur?
mitochondrial matrix
Where does electron transport chain and ATP synthase enzyme occur?
inner mitochondrial membrane
In glycolysis what is the 6-carbon molecule of glucose broken down into?
enzymes break it down into two 3-carbon molecules of pyruvate
What is substrate-level phosphorylation?
enzyme-catalyzed reaction that transfers a phosphate group from a substrate to ADP
What step does substrate-level phosphorylation occur?
glycolysis
What occurs in the pyruvate oxidation and kreb’s cycle?
Enzymes convert the 3-carbon pyruvate into a 2-carbon acetyl group, which enters the citric acid cycle and is completely oxidized to carbon dioxide
Is some ATP synthesized during the citric acid cycle?
yes
What causes free energy to be released in Oxidative phosphorylation – electron transport chain and chemiosmosis?
proton gradient created by chemisomosis
What occurs in Oxidative phosphorylation – electron transport chain and chemiosmosis?
electron are delivered to oxygen via electron transport chain
What uses the proton gradient as an energy source to make ATP?
ATP synthase
What are the two mechanisms for ATP synthesis?
substrate-level phosphorylation and oxidative phosphorylation
What does the donor molecule donate, and donate to, what does it become? During substrate-level phosphorylation
donates phosphate to ADP to create ATP
What enzyme is involved in oxidative phosphorylation?
ATP synthase
Where does the energy come from in oxidative phosphorylation?
proton gradient from the oxidation of glucose
Why is it called oxidative phosphorylation?
electrons from the proton gradient are donated to oxygen
Where does glycolysis get its energy from?
2 ATP
How many ATP are created from glycosisu?
4 ATP
What is the net gain of ATP in glycolysis?
2 ATP
Equation for glycolysis?
Glucose + 2 ADP + 2 Pi + 2 NAD+ + 4 e− + 4
H+ → 2 pyruvate + 2 ATP + 2 NADH + 2 H+ +
2 H2O
What does NAD+ become in glycolysis?
NADH
How many electrons and protons does NADH carry in glycolysis?
2 electrons and one proton
In the first step of glycolysis what is the enzyme involved?
hexokinase
What happens in the first step of glycolysis?
Glucose receives a phosphate from ATP, producing glucose-6-phosphate
What type of reaction occurs in the first step of glycolysis?
Phosphorylation reaction
What happens in the second step of glycolysis?
Glucose -6-Phosphate is rearranged to Fructose – 6- Phosphate
In the second step of glycolysis what is the enzyme involved?
Phospho gluco-isomerase
What type of reaction occurs in the second step of glycolysis?
Isomerization reaction
What happens in the third step of glycolysis?
Another phosphate group from ATP is attached to fructose-6-phosphate,
producing Fructose -1,6,bisphosphate
In the third step of glycolysis what is the enzyme involved?
Phosphofructokinase
What type of reaction occurs in the third step of glycolysis?
Phosphorylation reaction
What happens in the 4 step of glycolysis?
Fructose-1,6-bisphosphate is split into glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DAP)
In the 4 step of glycolysis what is the enzyme involved?
Aldolase
What type of reaction occurs in the 4 step of glycolysis?
HYDROLYSIS or CLEAVAGE
What happens in the 5 step of glycolysis?
The DAP produced in reaction 4 is converted into G3P, giving a total of two of these molecules per molecule of glucose.
In the 5 step of glycolysis what is the enzyme involved?
Triose phosphate isomerase
What type of reaction occurs in the 5 step of glycolysis?
Isomerization
What happens in the 6 step of glycolysis?
Two electrons and two protons are removed from G3P. Some of the energy released in this reaction is trapped by the addition of an inorganic phosphate group from the cytosol
(not derived from ATP). The electrons are accepted by NAD+, along with one of the protons.
The other proton is released to the cytosol.
In the 6 step of glycolysis what is the enzyme involved?
Glyceraldehyde-3-phosphate dehydrogenase or Triose phosphate dehydrogenase
What type of reaction occurs in the 6 step of glycolysis?
Dehydrogenation reaction or redox reaction
What happens in the 7 step of glycolysis?
One of the two phosphate groups of 1,3-bisphosphoglycerate is transferred to ADP to produce ATP (substrate-level phosphorylation reaction).
In the 7 step of glycolysis what is the enzyme involved?
Phosphoglycerate kinase
What type of reaction occurs in the 7 step of glycolysis?
: Substrate level Phosphorylation reaction
What happens in the 8 step of glycolysis?
3-Phosphoglycerate is rearranged, shifting the phosphate group from the 3rd carbon to
the2nd carbon to produce 2-phosphoglycerate
In the 8 step of glycolysis what is the enzyme involved?
Phospho-glyceromutase
What type of reaction occurs in the 8 step of glycolysis?
Mutase reaction—shifting of a chemical group to another within same molecule
What happens in the 9 step of glycolysis?
Electrons are removed from one part of 2-phosphoglycerate
and delivered to another part of the molecule. Most of the energy lost by the electrons is retained in the product, phosphoenolpyruvate.
In the 9 step of glycolysis what is the enzyme involved?
Enolase
What type of reaction occurs in the 9 step of glycolysis?
Dehydration
What happens in the 10 step of glycolysis?
The remaining phosphate group is removed from phosphoenolpyruvate and
transferred to ADP. The reaction forms ATP and the final product of glycolysis,
PYRUVATE.
In the 10 step of glycolysis what is the enzyme involved?
Pyruvate Kinase
What type of reaction occurs in the 10 step of glycolysis?
Substrate –level phosphorylation
What are the energy-requiring steps of glycolysis?
1-5, 8, 9
What are the energy-releasing steps of glycolysis?
6, 7, 10
How many NADHs’ are synthesized from 10 molecules of glucose in Glycolysis?
20
How many molecules of ATP are made from 15 molecules of glucose? what type of ATP production is this?
60, ?
In pyruvate oxidation what type of transport moves the pyruvate into the mitochondrial matrix?
secondary active transport
What is created from the oxidation of pyruvate?
CO2, acetyl-coenzyme A (acetyl-CoA), and NADH
What happens to the acetyl group of acetyl-CoA?
it enters the citric acid cycle
where does pyruvate oxidation occur in eukaryotes?
mitochondria
where does pyruvate oxidation occur in prokaryotes?
cytosol
Equation for pyruvate oxidation?
pyruvate + CoA + NAD
+ → acetyl-CoA + NADH + H+ + CO2
What happens in pyruvate oxidation?
removes CO2 from pyruvate and oxidizes the
remaining 2-carbon fragment to an acetyl group (CH3CO) which is carried by acetyl-CoA to the citric acid cycle
What happens in pyruvate oxidation?
removes CO2 from pyruvate and oxidizes the
remaining 2-carbon fragment to an acetyl group (CH3CO) which is carried by acetyl-CoA to the citric acid cycle
Is pyruvate oxidation exergonic or endergonic?
highly exergonic
What is pyruvate oxidation couple with?
endergonic synthesis of NADH from NAD+, H+, and
2e−
How many 3 carbon pyruvate molecules are there in pyruvate oxidation?
2
What does each 3 carbon pyruvate molecule contain?
1 CO2 (1 carbon is lost), 1 NADH, 1 acetyl-CoA (2 carbons)
How many CO2 molecules are released in pyruvate oxidation in a single molecule of glucose?
2
Is there any ATP molecules made by substrate level phosphorylation in pyruvate oxidation?
No
Does pyruvate oxidation occur in the absence of oxygen?
No
What is the Krebs Cycle also known as?
Citric Acid Cycle
What is the equation for the Krebs Cycle?
1 acetyl-CoA + 3 NAD+ + 1 FAD + 1 ADP + 1 Pi + 2 H2O → 2CO2 + 3 NADH + 1 FADH2 + 1 ATP + 3 H+ + 1 CoA
What does every molecule of acetyl-CoA electrons are transfered to?
3 NAD+ (NADH) and 1 FAD (FADH2)
What is the 1 reaction in the Krebs Cycle?
Condensation
What is the 2 reaction in the Krebs Cycle?
Isomerization
What is the 3 reaction in the Krebs Cycle?
First oxidation
What is the 4 reaction in the Krebs Cycle?
Second oxidation
What is the 5 reaction in the Krebs Cycle?
Substrate-level phosphorylation
What is the 6 reaction in the Krebs Cycle?
Third oxidation
What is the 7 reaction in the Krebs Cycle?
Hydration reaction
What is the 8 reaction in the Krebs Cycle?
Fourth oxidation andregeneration of Oxaloacetate
What happens in the 1 reaction in the Krebs Cycle?
A 2-carbon acetyl group carried by COA is transferred to oxaloacetate to form citrate.
What happens in the 2 reaction in the Krebs Cycle?
Citrate is rearranged to Isocitrate.
What happens in the 3 reaction in the Krebs Cycle?
Isocitrate is oxidized to alpha-ketoglutarate and one carbon is lost as carbon-dioxide and NAD+ is reduced to NADH and H+.
What happens in the 4 reaction in the Krebs Cycle?
Alpha-Ketoglutarate is oxidized to succinyl CoA and one carbon is released as Co2, and NAD+ is reduced to NADH and H+.
What happens in the 5 reaction in the Krebs Cycle?
CoA is released from succinate and this produces
energy which is used to convert GDP to GTP and
this in turn powers conversion of ADP to ATP. The
only ATP made directly by substrate level
phosphorylation
What happens in the 6 reaction in the Krebs Cycle?
Succinate is oxidized to fumarate. 2 electrons and
2 protons are removed and transferred to FAD to
produce FADH2.
What happens in the 7 reaction in the Krebs Cycle?
Fumarate is converted to Malate by the addition of
one water molecule
What happens in the 8 reaction in the Krebs Cycle?
Malate is oxidized to Oxaloacetate, reducing NAD+
to NADH and H+. This regenerated oxaloacetate
can reenter the cycle.
What is the enzyme in the 1 reaction in the Krebs Cycle?
citrate synthase
What is the enzyme in the 2 reaction in the Krebs Cycle?
aconitase
What is the enzyme in the 3 reaction in the Krebs Cycle?
isocitrate dehydrogenase
What is the enzyme in the 4 reaction in the Krebs Cycle?
ketoglutarate dehydrogenase
What is the enzyme in the 5 reaction in the Krebs Cycle?
Succinyl-CoA synthetase
What is the enzyme in the 6 reaction in the Krebs Cycle?
Succinate dehydrogenase
What is the enzyme in the 7 reaction in the Krebs Cycle?
Fumarase
What is the enzyme in the 8 reaction in the Krebs Cycle?
Malate Dehydrogenase
At the end of the Krebs Cycle what has glucose been oxidized to?
◦ 6 CO2
◦ 4 ATP (net)—6 total
◦ 10 NADH (6 krebs cycle, 2 pyruvate oxidation, 2 glycolysis)
◦ 2 FADH2
For each Acetyl-CoA entering the kreb cycle what occurs?
◦ Release 2 molecules of CO2 ◦ Reduce 3 NAD+ to 3 NADH ◦ Reduce 1 FAD (electron carrier) to FADH2 ◦ Produce 1 ATP ◦ Regenerate oxaloacetate
In glycolysis when there is too much ATP present what happens?
ATP allosterically inhibits phosphofructokinase, excess citrate also inhibits this enzyme
In glycolysis during feedback inhibition, what does NADH inhibit?
phosphofructokinase
In glycolysis during feedback inhibition, what is pyruvate kinase inhibited by?
high levels of ATP and Acetyl CoA
In glycolysis during feedback inhibition, what is pyruvate kinase activiated by?
high levels of Fructose 1,6-bisphosphate
In pyruvate oxidation during feedback inhibition, what is pyruvate dehydrogenase inhibition by?
high levels of NADH
In the citric acid cycle during feedback inhibition, what is citrate synthase inhibition by? (2)
high levels of ATP and high levels of citrate
NADH transfers its electrons to?
complex 1
FADH transfers its electrons to?
complex 2
Does complex 2 pump protons?
nope
Does complex 1, 3, and 4 pump protons?
yes
Is the proton concentration higher in the inner membrane compartment?
yes
What moves through ATP synthase?
protons
Where is ATP synthase located?
inner mitochondrial membrane
What is cyt c
a mobile electron carrier
How much energy is harvested from 1 molecule of NADH?
3 ATP
How much energy is harvested from 1 molecule of FADH?
2 ATP
Why does FADH only produce 2 ATP?
only generates protons from complex 3 and 4…less?
Is ADP + Pi endergonic or exergonic?
endergonic
Where does ADP + Pi get its energy from?
proton graident
Where does ADP + Pi get its energy from?
proton graident
Leaky?
no holes, just other proteins that can transfer protons
In ETC what does each complex do? (2)
create a proton gradient and transfer electrons to the next carrier
Where is complex II bound to in the ETC?
inner mitochondrial membrane on the matrix side
Describe the proton concentration gradient of the ETS?
high proton concentration in the inter membrane compartment and low proton concentration in the matrix
What are the 2 mobile electron carriers in ETC?
cytochrome c and ubiquinone (coenzyme Q)
What does the mobile electron carriers do?
shuttle electrons between the major complexes
What is a cytochrome?
proteins with a heme prosthetic group that contains an iron atom that accepts and donates electrons
Individual electron carriers of the ETS flow from (high/low) to (high/low) free energy?
high to low free energy
Do NADH and FADH2 contain a lot of free energy?
yes
NADH and FADH2 are easily reduced or ozixedes?
oxidized
The terminal electron acceptor O2 is easily reduced or oxidized?
reduced
Is electron movement in ETC sponatntous?
yes
What is a proton motive force?
stored energy produced by proton and voltage gradient. This energy is used for ATP synthesis and co-transport of substances to and from the mitochondria
What does ATP synthase do?
uses proton-motive force to add phosphate to ADP to generate ATP (phosphorylation)
—rotation of the headpiece
What are the 3 parts of ATP synthase?
basal unit, stalk, and headpiece
What bridges the basal unit and headpiece in ATP synthase?
peripheral stator
Where is the basal unit of ATP synthase located?
inner membrane
Where is the headpiece of ATP synthase located?
matrix
What is the theoretical energy yield for 1 glucose for bacteria?
38 ATP
What is the theoretical energy yield for 1 glucose for eukaryotes?
36 ATP
What is the theoretical yield of 1 NADH?
3 ATP
What is the theoretical yield of 1 FADH2?
2 ATP
What is the actual yield of 1 NADH?
2.5 ATP
What is the actual yield of 1 FADH2?
1.5 ATP
What is the actual energy yield for 1 glucose for eukaryotes?
30 ATP
What is the actual energy yield for 1 glucose for prokaryotes?
32 ATP
Why is there a difference between the theoretical and actual yield?
leaky inner membrane and use of proton gradient for other purposes than ATP synthesis.
How do you get the actual energy yield for 1 glucose for prokaryotic cells?
\+2 ATP from glycolysis
\+2 ATP from substrate-level
phosphorylation
\+10 NADH (2 from glycolysis,
2 from pyruvate
oxidation, 6 from krebs
cycle) x 2.5
\+2 FADH2 ( from krebs cycle)
X 1.5
= 32 ATP
How do you get the actual energy yield for 1 glucose for eukaryotic cells?
same as prokaryotic but subtract 2 ATP from getting to the mitochondria membrane
= 30 ATP
What experimental research did E. Racker and W. Stoeckenius do?
showed that the H+ gradient powers ATP synthesis by ATP synthase
In E. Racker and W. Stoeckenius experiment where was ATP synthesized?
only in the light
In E. Racker and W. Stoeckenius experiment how were the synthetic vesicles constructed and what did they contain?
They were constructed synthetic phospholipid membrane vesicles containing a segment of purple surface membrane from an archaean. The purple membrane contained only bacteriorhodopsin, a protein that resembles rhodopsin, the visual pigment of animals. Bacteriorhodopsin is a light-activated proton pump. The researchers illuminated the vesicles and then analyzed the concentration of H+ in them.
In E. Racker and W. Stoeckenius experiment what were the results?
light activated the bacteriorhodopsin to produce an H+ gradient, with H+ moving from the outside to the inside of the vesicle (like the movement from the mitochondrial matrix to the intermembrane compartment
and that the energy from the H+ gradient drove ATP synthesis by ATP synthase.
In E. Racker and W. Stoeckenius experiment what was the conclusion?
An H+ gradient—and, therefore, proton-motive force—powers ATP synthesis by ATP synthase.
What does the fate of pyruvate depend on?
oxygen avaiblity
What happens to pyruvate when oxygen is present?
pyruvate is oxidized to acetyl-CoA which enters the Krebs cycle via aerobic respiration
What happens to pyruvate when oxygen is not present?
pyruvate is reduced in order to oxidize NADH back to NAD+ via fermentation
What happens to pyruvate when there is no oxygen/ what is it converted to?
lactate
What does fermentation produce?
lactate and ehtanol
How does lactate affect your muscles?
makes them tired—-iron legs
Is NADH recycled?
yes
What are the two types of fermentation?
lactate fermentation and alcoholic fermentation
Where does lactate fermentation occur?
bacteria, plant tissues, skeletal muscle, makes buttermilk, yogurt, and dill pickles.
Does glycolysis need oxygen?
no
In lactate fermentation is carbon lost?
no
In alcoholic fermentation is carbon lost?
yes, 1 carbon is lost
What is are facultative anaerobes?
can switch between fermentation and full oxidative pathways depending on oxygen supply
What are some examples of facultative anaerobes?
E. coli, lactobacuilis…..
What are strict anaerobes?
Fermentation is the only source of ATP, cannot do oxidative phyospporyaltion
What type of environment do strict anaerobes like?
oxygen-free environments
Where can botulism be found?
in canned foods
What are sone examples of strict anaerobes?
bacteria like botulism and tetanus, and fungi
What are strict anerobes?
need oxygen for survivial
What is an example of a strict anerobe?
brain cells
How does cancer affect glycolysis? What is this effect called?
leads to abnormal glycolysis that generates larges amounts of lactate, and creates higher rates of glysocous
effect called Warburg effect
What is deamination?
where amino acids get an amino group removed
What is the difference in the respiration of a carbon fatty acid vs a 6-carbon glucose?
The respiration of a 6-carbon fatty acid yields 20% more energy than 6-carbon glucose.
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