Exam 3 Flashcards
How do organism use the acquired nutrients?
Amino acids get used up
Carbohydrates and lipids get burned as fuel
Energy is briefly stored as ATP
Energy is released
ADP and the third phosphate group is removed
Energy is consumed
ATP third phosphate group is added
Energy is used for membrane transport, cellular movement
Glucose for through why kind of reaction
Combustion
Combustion process
Burning glucose with oxygen to make carbon dioxide and water
Glucose to CO2 will releases energy and some energy is stored by taking ADP and phosphate and making ATP
Carbon atoms are oxidized during ADP+PO4 becoming ATP
Loss of electrons
Oxygen is more electronegative than carbon
Keeps more of the shared electrons
Carbon loses electron density
We need to count the number of bonds to oxygen
C 4 hydrogen most reduced carbon
C four bond o. Is the most oxidized
Oxidation
Loss of electrons
Reduction
Gain of electrons
Where is carbon oxidized
In cell metabolism
Every oxidation must be followed by a
Reduction
Biologically done by a coenzyme
Vice versa
NAD + IS
Oxidized
A small molecule that is derived from a small B vitamin
NADH is
Reduced
Also has a free floating proton
Coenzyme
Small molecule that is necessary for enzymes to work
Bucket analogy with NAD and NADH
When the bucket is empty it is NAD
And when it is full with 2 protons it is NADH
When NADH is reduced it is
High energy
Due to the 2 electrons carrying the energy with them
Second coenzyme
FAD oxidized AND FADH2 reduced
Bucket analogy
FADH2 high energy
FAD low energy
Aerobic cellular respiration
Glycolysis
Transition step
Citric acid cycle
Electron transport
Chemiosmosis
Glycolysis
Glucose with 6 carbon dioxide
Taking NAD and FAD(oxidized) to NADH and FADH2 (reduced)
-DH (ADP) to -AD(ATP)
Follow the carbon atoms
Follow the energy
Glycolysis properties
Sugar cutting
Universal metabolic pathway
Cytosol
Anaerobic
Cut glucose and partially oxidized
Makes ATP and NADH
Metabolic pathway
Series of enzyme linked reactions
Moving metabolically
10 steps
To go from glucose to 2 pyruvate
Investment phase
Taking ATP and using it
Taking 6c and cutting it into 2 3c
Payoff phase
Making 2 ATP and high energy 2 NADH
Typically glucose enters through
GLUT (facilitator transporter-follows it’s concentration gradient)
Step 1 glucose is phosphorylated by hexokinase 
Once, in the cytosol hexokinase is a first enzyme to initiate glycolysis
Taking glucose and an ATP and making glucose 6 phosphate plus ADP
EXERGONIC REACTION due to ATP investment
Glucose six phosphate is trapped in the cytosol, and can’t exit through GLUT
Kinase
Enzyme that move around phosphates
Step 2 glucose 6 phosphate to fructose 6 phosphate
Aldehyde to ketone (movement of where the double bone is placed between carbon and oxygen
Step 3 fructose 6 phosphate is phosphorylated again
We add another phosphate to fructose 6 phosphate
Making the reaction fructose 6 phosphate plus ATP goes = fructose 1,6 biphosphate plus ADP
EXERGONIC
Step 4 cutting (lysis step)
Fructose 1,6 bisphosphate is cut down the middle which produces 2 different 3carbon compound
Step five
Convert molecule with double bond in the middle with the molecule that has double bond at the end
Payoff phase overall
Everything is done twice per glucose
Extracting energy out
Glycolysis input
Glucose
2 ATP
4 ADP
2 NAD
Glycolysis output
2 pyruvate
4 ATP
2 ADP
2NADH
Glycolysis “follow the energy”
Net input: glucose, 2ADP,2NAD ENERGY COMES FROM GLUCOSE
Net output: 2 pyruvate,2 ATP, 2 NADH ENERGY LEAVES
Transition step
Pyruvate oxidation
Move carbon atoms from cytosol into mitochondria
Carbon is oxidized
One CO2 released per pyruvate
Mitochondria are complicated organelles
Two independent phospholipid bilateral; outer and inner membrane
More inner membrane than outer membrane
Three spaces: cytosol inter-membrane space, matrix
Pyruvate dehydrogenase in the mitochondria
Spans between the outer membrane and inner membrane
Big enough protein to cross two phospholipid bilayers
Acts as a transporter for pyruvate into the matrix
Twice per glucose
PD cuts pyruvate (cutting carbon 3 which gets oxidized) into acetly group
CO2 moves fast through phospholipid bilayers diffuse across mitochondrial membrane out into the blood
NAD+ is reduced to NADH
Because acetyl is highly active
Gets attached to a handle CoA temporarily chaperone that prevents acetly acid from doing unwanted reactions
Follow the carbon atoms pyruvate dehydrogenase
3c pyruvate to CO2 and AC-COA (2C)
Follow the energy pyruvate dehydrogenase
Pyruvate to NADH
Citric acid cycle general
Happens in mitochondrial matrix
Finish oxidizing carbon atoms
Store energy in reduced coenzymes
Cyclic metabolic pathway
Also called tricarboxylic acid cycle or Krebs cycle
Citric acid cycle
4c molecule that uses AC-COA , COA is released 6c compound and so on and so fourth individual carbon units are getting lost to CO2 within those individual units NAD turns to NADH
EVENTUALLY you’ll do GTP AND GDP AND THEN you’ll oxidize FAD TO FADH then back NAD and NADH
Step one citric acid
Starting with 4c compound oxaloacetic acid and acetyl COA
Citrate synthase takes OAA and takes carbon from acetly COA to make citrate acid and CoA
Citric acid cycle GDP to GTP
Energy is consumed to make an extra phosphate
Guanosine di phosphate and guanosine triphosphate
GTP turns to ATP by removing high energy phosphate and gluing it on ATP
Citric acid cycle
Input AC COA 2c per pyruvate, 2pyruvate per glucose
Output two co2
Citric acid follow the energy
Input: acetyl group
Output; 3NADH
1 FADH2
1 ATP OR GTP
electron transport and chemiosmosis will be placed together
as oxidative phosphorylation
goal of oxidative phosphorylation
re-oxidize coenzymes and transfer energy to ATP
where does electron transport take place
in the mitochondrial inner membrane
electron transport chain then
re-oxidizes the coenzyme which allows the citric acid cycle to continue to the chemiosmosis
within electron transport, energy is not transferred as ATP but as
proton electrochemical gradient
where does the citric acid cycle take place?
in the matrix
Complex 1
multiprotein complex embedded in the membrane that receives NADH (2 high energy electrons) as a transmembrane protein
complex one
once NADH brings the 2 high energy electron to the transmembrane protein, then it takes the 2 high energy electrons and turns NADH to NAD+ as a result,
Complex 1 is then reduced (temporarily holds to 2 electrons)
NAD+ then goes to the Citric Acid cycle or it wont continue.
what is necessary for the citric acid cycle to function
NAD+
Complex 1 passes 2 electrons to COQ
Phospholipids draw static move CoQ due to their tails moving side by side
COQ and Complex1 fit together. COQ picks up the 2 electrons. As a result, CoQ is now reduced and Complex 1 is oxidized. CoQ and 2 electrons drift away from complex 1 (fluid mosaic model)
CoQ and the 2 electrons
fluid mosaic lateral drift eventually leads COQ to complex 3. CoQ docks 2 electrons to complex 3. Oxidized CoQ and reduced Complex 3.
CoQ goes back to complex 1.
Complex 3 and Cytochrome C
Cytochrome C moves along the phospholipid bilayer reducing complex 3 and oxidizing cytochrome C. Cytochrome C then moves along to Complex IV.
Complex 4
picks up 2 electrons from cytochrome C.
Complex 4 passes electrons to oxygen. ONLY PLACE WE NEED OXYGEN
Oxygen picks up to electrons and makes molecular water.
how we breathe
oxygen picks up 2 electrons from complex 4.
serves as a terminal electron sync (Picks up electrons that are used already)
Electron transport
high energy NAD to complex 1-complex 4 to low energy electrons in water
why don’t the electrons go backwards?
NADH is extremely high molecule, so free energy (G)
as we pass the electrons to complex 1 the energy lowers and so on so forth
Electrons are losing energy as they move along the electron transport chain
if they went backwards , there would have to gain a lot of energy but since there is no pump to give energy the flow continues an exergonic way of energy
What happened to that energy
neither created nor destroyed, the energy is used to move proton. (active transport) Complex 1 moves proton
complex 1 can move
proton
inner membrane space of the mitochondria
higher acidity (7.2) than matrix (7.8) due to the higher proton concentration that is being transferred from complex 1.
Going against a chemical gradient
we need to consider the huge membrane potential
-180 internal is far more negatively charged that the ims
ETC chemical and chemical
going against the chemical gradient and electrical gradient
Complex 1, 3 and 4
as they receive the 2 electrons, they strip some energy and pump up protons onto the inner membrane space, lower energy electron is stored up in the proton
when they get low energy the pump up proton
**they get h Peyton’s from low concentration and pumps it up to the high concentration
energy transfer in ETC
NADH to proton chemical gradient
What about FADH2?
Complex 2 picks up electrons from FADH2 and reduces itself, passes electrons to COQ and then complex 3 and then cytochrome C
COQ receives electrons from
Complex 1 (NADH) and Complex 2 (FADH)
Complex 2 does not
move protons due to the lack of energy
FADH2 vs NADH
F only 2 protons pumped per reduced coenzyme
N 3 protons pumped per reduced coenzyme
Complex 4 needs
4 electrons to reduce one oxygen
requires two delivery from cytochrome c
Failure that Complex 4 does not receive electrons fast enough
reactive oxygen species like hydrogen peroxide
NADH made in the citric acid cycle is in the (?) spot in complex 1
the right spot
how do we get the NADH produced from glycolysis in the cytosol to the mitochondria?
electron shuttle
electron shuttle
dropping off and picking up electrons
DHAP and G3P serve as electron carriers,
How DHAP and G3P differ
DHAP is oxidized G3P is reduced
NADH Reduces to NAD+ and those electrons are transferred to DHAP which reduces G3P
G3P TRANSPORT
has a facilitated transporter in the outer membrane of mitochondria high concentration to low concentration chemical gradient
G3P to innermembrane
G3p oxydized to DHAP and moves to facilitated transport which works like FAD to FADH2
G3P to innermembrane
G3p oxidizes to DHAP and moves to facilitate transport which works like FAD to FADH2
DHAP moves through a facilitated transporter to the cytosol high to low concentration able to us e it in the electron transport chain
isozymes
two different enzymes, catalyzing the same reaction
where are isozymes present in the electron shuttle
cytosol and inner membrane
most other [?] enter glycolysis
carbohydrates, once they’re broken down to monosaccharide get, broken up and adjust to fit in the glycolysis
starch gets eaten up by
salivary and pancreatic amylase and depolymerizes glucose
Fructose
adds a phosphate when the cytol of a cell to carbon number 6 and we end up with fructose phosphate
Sucrose
disaccharides of glucose and fructose cut up
Fatty acids
oxidized in mitochondria through beta-oxidation
the first step to beta oxidation
attaching a molecule of CO enzyme A (same as transition state)
Beta oxidation
start with 14 carbon fatty acid NAD is inserted and reduces as NADH+
FAD enters and reduces as FADH2
left with Acetly CoA (two carbon CoA) and short and fatty acid
leaves as carbon fatty acid
gets shorter and shorter
left over Ac-CoA goes straight to
citric acid cycle from citric synthase
14 carbon fatty acid goes through 7 cycles of B-oxidation
produces 7 Acetly-CoA+ 7NADH 7FADH
left over FADH and NADH go to
oxidative phosphorylation through complex 1 and 2 and will be turned to ATP or ADP+PO4
each turn in the citric acid cycle (7 cycles of citric acid cycle)
14 Co2+ 7ATP (or GTP) + 21NADH 7 FADH
Amino Acid can be used to synthesize new protein or
burned for energy
20 different amino acids
20 different paths
Amino acid process begins with
deamination (getting rid of the amine group
once it is modified it can go into the citric acid cycle
o2 is only needed by
terminal electron acceptor used as a substrate for complex 4
without o2
oxidative phosphorylation stops
complex 4 cant move any electrons
electrons backup through electron transport chain
NAD+ and FADH2 plumet
if oxidative phosphorylation stops
the citric acid cycle stops due to the lack of oxidative coenzymes
anaerobic metabolism
organisms live without O2 and survive without o2
glycolysis does not need o2
directly
net yield+
2 atp
when you keep running glycolysis
theres an enzyme problem- NAD plus levels go down and down but NADH go up
If NAD+ doesnt work
glycolysis does not work
fermentation step
in humans happens within enzyme lactate dehydrogenase (3carbon)
pyruvate (product of glycolysis) is reduced while NADH is oxidized
and lactate is a product of this reaction
glycolysis + fermentation equal
anaerobic metabolism
fast but inefficient
fermentation from lactate deyhydrogenase
fermentation
lactate dehydrogenase
lactate
leaves any muscle cell that produces it by facilitated transported
water soluble dissolves in the plasma
what absorbs lactate
the liver
different isozymes of lactate dehydrogenase
converted back to pyruvate
same reaction as the muscle but in reverse
lactate is oxidized to pyruvate and NAD is reduced to NADH
Gluconeogenesis
pyruvate to glucose
pyruvate runs “glycolysis backwards”
7 get shared between gluconeogenesis and glycolysis
consumes 2 NADH and 6 ATP per glucose
Cori cycle
liver produces glucose which gives it to the muscle. The muscle takes it through glycolysis and produces lactate from glycogen. The lactate from the muscle cell is taken to the liver through gluconeogenesis
ATP provides a very [?} term energy storage
short
at low energy demands
high energy phosphates are stored
High energy sources
creatine
creative stores
high energy phosphates
creatine kinase
takes ATP and removes a phosphate and moves it over toCreatine Phosphate
ADP goes through oxidative phosphorylation
When high energy demand. Creatine kinase takes the phosphate from creatine phosphate, add it to ADP to make ATP
Energy can be stored as
glucose or glycogen (glucose polymer) mostly in the liver and muscle
energy can also be stored as triglycerides in
adipose tissue
you have to make Ac CoA first –> fatty acids
very high energy density
more efficient way of strong energy
mass/mass
Energy storage speed and capacity
ATP fast low capacity
Creatine
GLycogen
Triglycerides Slow High capacity
Synthesizing glucose from
CO2 to make sucrose, starch and other carbohydrates
photosynthesis is highly
endergonic
In glucose we will
build carbon dioxide to glucose adding in energy
Photosynthesis is a very reduced pathway
taking Co2 and reducing it to Glucose
as we reduce Carbon we will oxidize water to oxygen
reduction
adding a hydrogen
oxidation
removing a hydrogen
Following the carbon atoms and energy transfers in
photosynthesis
Light-dependent reactions
capture energy from light
store in reduced coenzyme (NADPH) and ATP
Light independent reactions
carbon fixations (CO2 stops being a gas and begins being incorporated to carbohydrate molecules)
calvin cycle (metabolic pathway)
consumes ATP and re-oxidized coenzyme (NADP)
NADP
phosphate on riboglucose at the bottom
no difference in chemical energy that can be stored
picks up high energy electrons
enzymes discriminates based on the phosphate at the bottom
synthetic reactions taking harvested energy for larger moleucles
many organisms are photosynthetic
microbials also use photosynthesis
where is the major site of photosynthesis in plants
leaf mesophyll cells occurring at the chloroplast
gas exchange in plants occurs in
stomata which open or close to the needs of the plants (acts as a lungs)
chloroplast structure
outer membrane, innner membrane, thylakoid membrane
with four spaces: cytosol. intermembrane space, stroma, and thylakoid lumen
where does the action happen in the chloroplast
thylakoid membrane seperated in stroma and thylakoid lumen
light spectrum
as radiation we see between 400 and 800 nm
{/} wavelengths of lioght are absorbed by plant pigments
some
chlorophyll
blue light and red light from the sun got absorbed
green light got reflected which is why the pants are green
chlorophyll molecules (and others) are held in a
large photosystem complex within the thylakoid membrane
has phospholipid bi layer -is a large disc that has many proteins within those two membranes
what makes up the photosystem complex
protein and chlorophyll
each photosystem contains many
chlorophyll and related molecules to increase the chances of the light photon to hits a chlorophyll
antenna complex
areas (chlorophyll) that are waiting to capture the radio signal (light photon)
light captured from the sun will cause the affected chlorophyll to activate a chain reaction of chlorophyll being activated which eventually reaches the reaction center
reaction center
pair of molecules that are able to use that energy given from the sun
at the reaction center
light energy is converted to chemical energy
an electron pair is moved to a higher energy state and becomes energized
transferred through different proteins and then out of the photosystem
photosystem
electrons are stolen from the water making the water oxidized which produces oxygen
process so far
light energizes electrons, those energized electrons leave and then take electrons from water to replace those electrons and then those will be energized when another photon comes
the photon of light hits photosystem 2
takes electrons away from water and energizes
oxygen can leave by simple diffusion to the stomata and being released to the atmosphere
energized electrons
go through the chloroplast between the stroma and thylakoid lumen
electron transport chain of chloroplast
passing energized electrons to Plastoquinone
PQ moves via fluid mosaic model and takes it to cytochrome complex
cytochrome complex passes energized electrons to plastocyanin
PC diffuses to photosystem 1 with energized electrons
now energized electrons get handed to NADP+ reductase (reduces NADP+ to NADH)
At photosystem 1 energized electrons
have lost most of their energy thus are re-energized with new sunlight
Again, why don’t electrons move backwards
energy is being used to go through the electron train transport, to go backwards it so acquire energy that is nowhere to be found
where did the energy go?
cytochrome complex pumps protons to the thylakoid lumen
cytochrome complex in the bilayer saves some of the energy and pumps protons into the lumen protons are being pushed against their electrical gradient
lumen will be more acidic than stroma
what can we do with the proton gradient
ATP synthase can exist as a protein to serve as a proton gradient that will allow protons to move with the electrical gradient into the stroma and mate with endergonic synthase with ADP
Light-dependent reaction. Energy transferred from {} to {} and {}
water to cytochrome complex and atp synthase
we produce ATP and NADH to power carbon fixation but ratio is off within carbon fixation cycle
we need more ATP per NADPH
fix the ratio of carbon fixation
allow a different pathway at photosystem one
which can transfer energized electrons to NADP reductase or PQ
ALWAYS come from Plastocyanin
energy diagram noncyclic electron flow
energized electrons from photosystem one can move to plastoquinone or plastocyanin
MAKES ATP but not NADPH
Light-independent reactions
not directly dependent on light
carbon fixation reactions
cyclic metabolic pathway in the stoma (calvin cycle, calvin-benson cycle, carbon fixation cycle)
key enzyme is rubisco
Ribulose bisphosphate carboxylase MOST ABUNDANT ENZYME
due to the low velocity
5c + CO2—> 2 3C
once every six cycles
two 3C molecules leave
3 carbon from rubisco
go through a similar process as gluconeogenesis to build up a glucose molecule
glucose can be made into sucrose, starch, cellulose, and other carbohydrates
can be exported from mesophyll cells to feed the rest of the plant
