Ch 3: Cellular Energy
Fats have _____ kcal/gram and are long-term energy stores
9
Beta-oxidation is an important process that explains why fats yield _____ kcal/gram.
9 kcal/gram
GTP is guanosine triphosphate. It is an ________ _________ triphosphate, just like ATP.
RNA nucleoside
the process of powering an energy-requiring reaction with an energy-releasing one
Reaction coupling
The ____________ ____________ states that aerobic bacteria were internalized as mitochondria while the photosynthetic bacteria became chloroplasts.
endosymbiotic theory
the ability to do work - i.e., to create some change in a biological system, such as ourselves.
energy
Glycolysis has two main phases: an _______ ________ phase, and an ______ ________ phase.
energy investment phase, and an energy payoff phase
Humans absorb digested fats at _______ of the ______ ________.
enterocytes of the small intestine
oval shaped organelles found in eukaryotic cells. They float around in the cell's cytosol, and because they are organelles, they are membrane-bound - with two membranes! (for energy)
mitochondria
the powerhouse of the cell
mitochondria
which probably evolved/was engulfed first? mitochondria or chloroplasts?
mitochondria
Beta-oxidation occurs in the ________ ________ of a eukaryotic cell's mitochondria.
mitochondrial matrix
The Krebs cycle occurs in the ________ ________ in eukaryotes
mitochondrial matrix
as the proton-motive force of the big fan spins, ATP synthase catalyzes the condensation of ADP + P into ATP in the __________ _______
mitochondrial matrix
the area beneath the inner membrane of the mitochondria is the _________ ________
mitochondrial matrix
As the redox reactions occur, the protein complexes pump protons from the _______ _______ to _______ _______
mitochondrial matrix to intermembrane space
The ETC and chemiosmosis generate ATP through _______ _______
oxidative phosphorylation.
FADH₂ becomes ______ as it reduces complex-II
oxidized
NADH becomes ________- as it reduces complex-I
oxidized
Two acetyl-CoA molecules are (reduced/oxidized) by the Krebs cycle for every one glucose.
oxidized
Aerobic cellular respiration is a sizable catabolic pathway that requires _________.
oxygen
_________ serves as the final electron acceptor for aerobic electron transport chain
oxygen
Before amino acids undergo cellular respiration, they must undergo oxidative deamination in the liver. Here, ammonia (NH₃) molecules are removed from the amino acid to create a slightly different molecule that is easier to shuttle into cellular respiration. The ammonia that gets cleaved off is _____ to ______.
toxic to vertebrates
Most fats exist as _________, which contain three (tri-) fatty acid tails attached to a single, three-carbon glycerolbackbone.
triglycerides
NADH is more effective than FADH₂. It travels directly to complex-________ in the electron transport chain and donates its electrons to it.
complex-I
mitochondria have 2 membranes: The outer membrane surrounds the entire surface area of the mitochondrion, while the inner membrane has many indentations called _________
cristae
Glycolysis occurs within the _________ of the cell
cytosol
Pyruvate manipulations occur in the ____________ for prokaryotes, because they do not have membrane-bound organelles.
cytosol
glycolysis takes place in the
cytosol
glycolytic NADH coenzymes lie in the _______ of the cell.
cytosol
the krebs cycle takes place in the _________ for prokaryotes (they do not contain membrane-bound organelles).
cytosol
in order to pyruvate to be manipulated after glycolysis, pyruvate molecules must first pass from the ________, and into the _________ _________.
cytosol to mitochondrial matrix
in alcohol fermentation, the pyruvate will be ________ to lose carbon as carbon dioxide.
decarboxylated
Many aquatic species and invertebrates excrete ammonia __________. They do not need to convert it to a safer compound.
directly
aerobic oxidative phosphorylation (directly/indirectly) depends on oxygen.
directly
Because glycogen can enter glycolysis as glucose-6-phosphate, it (does/does not) require the hexokinase reaction that results in the investment of an ATP.
does NOT
Glycolysis (does/does not)need oxygen
does not
Protons travel ________ their electrochemical gradient through ATP synthase.
down
With each transfer, the electrons release a little free energy that the ETC uses to form an ___________ gradient.
electrochemical
Proton pumping forms an ________ _________ across the inner membrane.
electrochemical gradient
High-energy electrons travel through the ETC because each ETC protein is more "_________ __________" than the last.
electron hungry
The __________ ________ _________(ETC) has proteins and other organic molecules, which pass high-energy electrons from one component to the next.
electron transport chain
the oxidative phosphorylation phase of cellular respiration utilizes the _________ _______ chain and _______
electron transport chain and chemiosmosis
the energy produced by ATP hydrolysis is free energy that can then power __________ processes to keep cells out of chemical equilibrium.
endergonic
When it finally comes time to break down our stored triglycerides for energy, we need to remove the _______ from the adipose tissue. Again, we need a lipase to do this.
triglycerides
Humans need to digest fats before absorbing them. Lipases convert _______ into free ____ ______ and alcohols
triglycerides into fatty acids and alcohols
true/false: With each transfer of electrons, the electron source (i.e., the thing that was carrying the electrons) becomes oxidized, while the electron target (i.e., the thing that accepts the electrons from the electron source) becomes reduced
true
true/false: Without oxygen, oxidative phosphorylation would stop, which means the regeneration of the coenzymes needed for pyruvate oxidation (NAD⁺) and the Krebs cycle (NAD⁺ and FAD) would also stop.
true
true/false: both mitochondria and chloroplasts have circular DNA and ribosomes separate from the nucleus (DNA) and cytosol (ribosomes)
true
true/false: if oxygen is not available as the final electron acceptor, the processes that follow glycolysis cannot occur, and NAD⁺ cannot be regenerated.
true
true/false: it is hard to store much glucose as glycogen at one time, because glycogen is a hydrophilic polymer that attracts water and takes up a lot of cell volume.
true
true/false: red blood cells (erythrocytes) function to carry as much oxygen as possible, so they lack most organelles (including mitochondria).
true
After pyruvate loses a carbon dioxide, it is now a ______-carbon molecule.
two
Because _________ G3P molecules result from the oxidation of one glucose molecule during the energy investment phase, the energy payoff phase occurs twice to produce four ATP, two NADH, and two pyruvates.
two
Because two acetyl-CoA molecules are produced in the pyruvate manipulation reactions, the Krebs cycle will occur _______ times for each glucose that enters cellular respiration.
two
Fructose-1,6-bisphosphate is unstable, so it breaks down into ______________ three-carbon sugars at the end of the energy investment phase.
two
So, for every ________ acetyl-CoA molecules: 4 CO₂, 6 NADH, 2 FADH₂, and 2 GTP (ATP).
two
in glycolysis there is an energy investment of how many ATP?
two
when acetyl-CoA joins oxaloacetate to form citrate and the six carbon molecule will lose _______ of its carbon atoms as this many carbon dioxide molecules
two
hepatocytes contain an enzyme that "_______" the hexokinase reaction of glycolysis.
undoes the hexokinase reaction
reaction coupling allows a(n) (favorable/unfavorable) reaction to powered by a favorable reaction, making the net ΔG negative (exergonic = releases energy + spontaneous
unfavorable
As a whole, ATP molecules are ________ because the three phosphate groups are all negatively charged and repel each other.
unstable
Sharks, most amphibians, and mammals (like humans) convert the ammonia to ______ BEFORE they excrete it as urine.
urea
Insects, reptiles, and birds convert the ammonia to _______ _______ before excreting it.
uric acid
As electrons reach the end of the ETC, they are passed on to an oxygen molecule to form
water
The electrons are passed along the electron transport chain until they reach the final electron acceptor, to form ________!
water
Yeast use alcohol fermentation, which is similar to lactic acid fermentation in that it regenerates NAD⁺ for glycolysis to continue making two ATPs. However, the electrons from NADH (will/will not) reduce the pyruvate produced.
will NOT
As NAD⁺ is regenerated, complex-I undergoes a (oxidation/reduction).
reduction
In the first step of the Krebs cycle, a two-carbon acetyl-CoA joins four-carbon oxaloacetate to form six-carbon citrate AND NAD⁺ undergoes _________ to NADH each time a carbon dioxide leaves.
reduction
after the four-carbon molecule transforms back into four-carbon oxaloacetate, another NAD+ undergoes a ______ to NADH.
reduction
in the enterocytes of the small intestine, free fatty acids and monoglycerides enter the cell. Once contained within the enterocyte, the free fatty acids and monoglycerides will ________ into _______.
reform into triglycerides
phosphofructokinase (PFK) is an essential _________ enzyme.
regulatory
Aerobic respiration is exergonic with a ΔG of _______ kcal/glucose
- 686 kcal/glucose
_______- uses the energy stored in the electrochemical gradient (from the electron transport chain) to synthesize ATP.
Chemiosmosis
there are protein complexes I-IV in the electron transport chain. Electrons tend to travel from complex ______ to ______
1 to 4
prokaryotes do not need to use any shuttle systems for glycolytic NADH to reduce complex-I. Therefore, they will produce ______ ATP from the 2 NADH made in glycolysis.
6
Because FADH₂ reduces a later complex than NADH, a single FADH₂ will produce about __ ATP.
2
______ GTP (energetically equivalent to ATP) result from substrate level phosphorylation in the Krebs cycle.
2
a net amount of ______ ATP result from substrate-level phosphorylation in glycolysis.
2
net products of glycolysis
2 ATP, 2 pyruvate, 2 NADH
for each glucose that enters cellular respiration, the pyruvate manipulations produce how many of each 3 things??
2 carbon dioxide, 2 NADH, 2 acetyl-CoA
The krebs cycle produces ___________ carbon dioxide, ________ NADH, __________ FADH2, and _______ GTP
2 carbon dioxide, 3 NADH, 1 FADH2, and 1 GTP
A single NADH coenzyme will produce about ______ ATP (NADH from glycolysis produces less).
3
The electrons FADH₂ release will only be used for pumping protons at complex-_____ and ______ because FADH₂ passes its electrons to a complex later in the ETC, it will contribute to less proton pumping
3 and 4
________ ATP come from oxidative phosphorylation
32-34
Carbohydrates have ____ kcal/gram
4
Proteins give ______ kcal/gram and can contribute to gluconeogenesis at the liver
4
carbohydrates are the body's preferred energy source because they are rapidly and efficiently catabolized to provide _______ kcal/gram.
4 (kcal/gram)
G3P undergo redox reactions to produce _______ ATP, ____ pyruvate, and _____NADH
4 ATP, 2 pyruvate, and 2 NADH
for each glucose molecule that makes two acetyl-CoA molecules the Krebs cycle makes _________ carbon dioxides, _______ NADH, ________ FADH₂, and _______ GTP.
4 carbon dioxides, 6 NADH, 2 FADH₂, and 2 GTP.
Proteins provide _______ kcal/gram (lower energy yield) and we are breaking down the proteins that are body needs for essential bodily functions!
4 kcal/gram
As the redox reactions occur, the protein complexes pump protons from the mitochondrial matrix into the intermembrane space, forming an electrochemical gradient. This chemiosmotic gradient will be used to create _______.
ATP
the enzyme _____ ______ is responsible for synthesizing ATP.
ATP synthase
________ organisms are similar to obligate anaerobes in the sense that they cannot use oxygen; therefore, they only utilize anaerobic respiration or fermentation. However, the presence of oxygen does not poison them.
Aerotolerant
__________ organisms are similar to obligate anaerobes but can live with oxygen
Aerotolerant
_________ ________makes many reduced coenzymes and acetyl-CoA → tons of ATP
Beta oxidation
(Catabolic/anabolic) processes break down large macromolecules into smaller pieces (think catabolism ~ cannibalism), and usually release energy in the form of adenosine triphosphate (ATP).
Catabolic
__________ reactions release free energy, so they are an example of exergonic reactions (energy release).
Catabolic
_______ energy is a unique type of potential energy, where the chemical bonds serve as a store of energy, and has the potential to be used to do work. .
Chemical energy
__________ harnesses energy stored within the proton gradient to synthesize ATP as protons diffuse across the inner membrane, from an area of high concentration (the intermembrane space) to an area of low concentration (the mitochondrial matrix).
Chemiosmosis
____________ are lipoprotein transport structures formed by the fusing of triglycerides with proteins, phospholipids, and cholesterol.
Chylomicrons
After the decarboxylation and oxidation steps, the remaining acetyl group will bind to a particular coenzyme, known as __________ _________ (____)
Coenzyme A (CoA)
in fermentation, once oxygen has become available again, humans can use a process called the _______ cycle to convert lactate back into glucose.
Cori cycle
two types of 3 carbon sugars in glycolysis
DHAP and G3P (dihydroxyacetone phosphate and glyceraldehyde-3-phosphate)
_________ releases glucose-6-phosphate from glycogen, allowing it to enter glycolysis.
Glycogenolysis
__________ converts a six-carbon glucose molecule into two three-carbon compounds called pyruvate
Glycolysis
As FADH₂ reduces a complex, it leads to the regeneration of ______ (the oxidized form)
FAD
_________ _______ can utilize aerobic respiration, anaerobic respiration, or fermentation. However, because aerobic respiration generates the most ATP, they will be undergo aerobic respiration if they are able to (if oxygen is present)
Facultative anaerobes
_________ ________can respire aerobically, anaerobically, or ferment
Facultative anaerobes
__________ is a unique anaerobic pathway
Fermentation
__________ ATP produced - ________ ATP invested = two net ATP from glycolysis.
Four ATP produced, two ATP invested
in the krebs cycle, ________ is produced via substrate-level phosphorylation
GTP
______-______ _______have a high density of proteins. They are generally considered to be healthy because they take cholesterol away from peripheral tissues and deliver it to the liver.
High-density lipoproteins (HDLs)
Protons cannot diffuse directly across membranes because membranes are (hydrophilic/hydrophobic).
hydrophobic
Before a fatty acid chain enters beta-oxidation, we need to activate the entire chain via the investment of ATP. This is an investment of ATP consumption to produce more ATP down the road. Now, it can go through a series of cleavages into two-carbon acetyl-CoA molecules. Each of the acetyl-CoA molecules will then travel to the ____ _______ As it is chopped up, it also produces NADH and FADH₂, which can be used to make ATP.
Krebs cycle
____-_____ _________have a low density of proteins. They are generally considered to be unhealthy because they deliver cholesterol to peripheral tissues via the bloodstream.
Low-density lipoproteins (LDLs)
________ pathways string together individual chemical reactions, where the product of an earlier reaction serves as the reactant for the next.
Metabolic pathways
_______ are similar to obligate aerobes, but too much oxygen will kill them
Microaerophiles
_________ are similar to obligate aerobes in the sense that they cannot live without oxygen. Therefore they cannot undergo anaerobic respiration or fermentation. However, high concentrations of oxygen are harmful to them.
Microaerophiles
________ contain the other one-third of glycogen that is NOT held in the liver
Muscles
when NADH travels directly to complex I and donates an electron to it, NADH goes from being reduced to oxidized and becomes __________
NAD+
the primary purpose of fermentation is to oxidize _____ back to _______ so that glycolysis can continue to make ATP.
NADH back to NAD⁺
Glycolysis also extracts high-energy electrons as the glucose is broken down, using them to reduce ________ (a coenzyme) into ________, which may travel to the electron transport chain for further ATP creation.
NAD⁺ into NADH
_______ _______ are organisms that can only metabolize their fuel sources via aerobic respiration. They can not undergo fermentation.
Obligate aerobes
______ _______ will only metabolize their fuel sources via anaerobic respiration or fermentation. Oxygen is toxic to them.
Obligate anaerobes
________, like bacteria, carry out the entirety of cellular respiration in their cytosol, and their ETC is in their cell membrane. Thus, they do not need to use any shuttle systems for glycolytic NADH to reduce complex-I.
Prokaryotes
The energy payoff phase produces ______ ATP through substrate-level phosphorylation, _______ NADH electron carrier, and _______ pyruvate for each G3P that enters.
TWO atp, ONE nadh, and ONE pyruvate
Anabolic reactions _________ free energy, so they are an example of endergonic reactions (requires energy).
absorb
both mitochondria and chloroplasts have circular DNA and ribosomes separate from the nucleus (DNA) and cytosol (ribosomes) because at one point they likely were free lively aerobic cells, that eventually were ________ by other cells to form eukaryotes (explained by the endosymbiotic theory).
absorbed
Fats undergo digestion (using lipase enzymes) before _________ at the enterocyte
absorption
Mitochondria are found in most eukaryotic cell types. However, their __________ varies depending on the cell's particular energy needs.
abundance
in alcohol fermentation, the pyruvate will be decarboxylated to lose carbon as carbon dioxide. the leftover molecule is _________
acetaldehyde
after pyruvate loses a carbon dioxide, it is now a two-carbon molecule that will undergo oxidation to become a two-carbon ________ _______.
acetyl group
Free fatty acids enter cellular respiration as _______-______molecules, which is made possible via a process called beta-oxidation.
acetyl-CoA
The intermembrane space of the mitochondrion is (basic/acidic) due to the gradient.
acidic
the region between the outer and inner membranes is the intermembrane space (basic/acidic)
acidic
Cells called ________ store triglycerides. They come together to form adipose tissue.
adipocytes
The multi-compartment organization of a mitochondrion is useful for _________ _________ respiration.
aerobic cellular
________ ________ respiration occurs in the presence of oxygen to produce an abundance of ATP
aerobic cellular respiration
two central pathways our cells use to catabolize carbohydrates: ______ respiration or _______ respiration
aerobic or anaerobic
ATP hydrolysis (energy releasing) moves ions ________ their concentration gradient (energy requiring).
against
The hormone sensitive lipase enzymes create free fatty acids and glycerol molecules via lipolysis. The free fatty acids and glycerols can then travel through the blood via a multitude of ways. ONE way is that the fatty acids can travel in their free state (not esterified to glycerol) by binding to a particular protein called _________.
albumin
Yeast use _______ ________, which is similar to lactic acid fermentation in that it regenerates NAD⁺ for glycolysis to continue making two ATPs. However, the electrons from NADH will not reduce the pyruvate produced.
alcohol fermentation
Alcohol fermentation produces the ethanol found in _______ _______
alcoholic beverages
When we consume proteins, we break them down into _____ _______
amino acids
Oxidative deamination creates toxic __________
ammonia
Before amino acids undergo cellular respiration, they must undergo oxidative deamination in the liver. Here, ______ (___)molecules are removed from the amino acid to create a slightly different molecule that is easier to shuttle into cellular respiration.
ammonia (NH3)
_________ processes extract energy from ATP and use it to build larger, more complex macromolecules, where the energy is stored.
anabolic
Glycolysis is the only pathway in aerobic glycolysis that does not require oxygen, it an __________ process
anaerobic
__________ _________ respiration creates a smaller amount of ATP when oxygen is not readily accessible.
anaerobic cellular respiration
Before a fatty acid chain enters ________ ______, we need to activate the entire chain via the investment of ATP. This allows us to produce more ATP down the road.
beta-oxidation
ATP synthase acts like a ____ ____ that spins as protons travel through it, the proton-motive force.
big fan
High-density lipoproteins (HDLs) have a high density of proteins. They are generally considered to be healthy because they take cholesterol away from peripheral tissues and deliver it to the liver. Once at the liver, the cholesterol can be used to make _______, which ultimately gets expelled from the body
bile
Glycogen is a highly _________ ________, meaning it is a polymer of many monomeric carbohydrates.
branched polysaccharide
metabolic pathways are either anabolic or catabolic. catabolic pathways _____ _____ molecules and (in the process) ________ energy
break down molecules and release energy
metabolic pathways are either anabolic or catabolic. anabolic pathways _____ _____ molecules and ________ energy
build up molecules and require energy
Acetyl-CoA from free fatty acids (can/cannot) contribute to gluconeogenesis
cannot
once in the mitochondrial matrix, the pyruvate molecules (3 carbons) will be decarboxylated to release a carbon atom as _______ ___________.
carbon dioxide
the krebs cycle produces what four things?
carbon dioxide, NADH, FADH2, and GTP
in the krebs cycle, each of the first two intermediates contains three ___________ functional groups
carboxylate
cellular respiration is a (anabolic/catabolic) process
catabolic
in prokaryotes the electron transport chain occurs in the _______ ______
cellular membrane
Amino acids need to undergo oxidative deamination before _______ _______
cellular respiration
mitochondria make many ATP molecules through __________ __________
cellular respiration
Fats travel from enterocytes to adipocytes via ________ and ________
chylomicrons and lacteals
the mitochondrial matrix contains it's own _________ ______and __________
circular DNA and ribosomes
In the first step of the Krebs cycle, a two-carbon acetyl-CoA joins four-carbon oxaloacetate to form six-carbon ________.
citrate
the krebs cycle is also called the citric acid cycle because _______ is the first molecule produced
citrate
another name for the Krebs Cycle
citric acid cycle
DHAP and G3P sugars exist in __________, using an isomerase enzyme to convert back and forth between the two forms
equilibrium
the attachments in fats exist as _________ bonds and dehydration reactions make them
ester bonds
in ALCOHOL fermentation, NADH will reduce acetaldehyde into ________
ethanol
ATP hydrolysis reactions release free energy, making them spontaneous ( -∆G) and ___________.
exergonic
Aerobic respiration is hugely __________, with a ΔG of - 686 kcal/glucose (this number does show up on DATs).
exergonic
true/false: NADH can pass through the inner membrane of the mitochondrion to reduce complex-I.
false (NADH CANNOT pass through the inner membrane of the mitochondrion to reduce complex-I.)
true/false: The preference of fuel sources is: carbohydrates > proteins > fats
false (carbohydrates > fats > proteins)
true/false: mitochondria are found in eukaryotes and prokaryotes
false (prokaryotes lack membrane-bound organelles found in eukaryotic cells. Thus, prokaryotes have no mitochondria)
The hormone sensitive lipase enzymes create free ______ _______ and _____ molecules via lipolysis.
fatty acids and glycerol
after substrate-level phosphorylation, the four-carbon compound will then be manipulated again, passing electrons to _______ _______ ________, which is another electron carrying coenzyme similar to NAD⁺. The FAD undergoes a reduction to FADH₂.
flavin adenine dinucleotide (FAD)
G3P molecules then undergo a series of redox reactions to produce _________ ATP molecules through __________-_________-___________
four ATP molecules through substrate-level-phosphorylation
fructose-6-phosphate gets phosphorylated to become ________-__-________
fructose-1,6-bisphosphate
When a glycerol molecule travels to the liver, it can undergo a conversion to enter glycolysis or make new glucose via ________ at the liver.
gluconeogenesis
carbohydrates can contribute to glycogen via __________
gluconeogenesis
another term for liver cells
hepatocytes
phosphorylation during the energy investment phase is carried out by __________, and it is a non-reversible process.
hexokinase
in the Cori cycle, once the lactate is at a hepatocyte, the lactate can oxidize back into pyruvate which can then form _____ through ______
glucose through clugoneogenesis
after phosphorylation, the glucoses is now called ________-_____-__________ (because a phosphate was added to carbon six)
glucose-6-phosphate
___________, our storage form of glucose, enters glycolysis.
glycogen
When energy and fuel sources are abundant, other carbohydrates can go toward making new glucose to be stored as glycogen; this is called ________
glycogenesis
The storage form of glucose is glycogen, which is broken down by __________
glycogenolysis
Levels of various molecules influence the speed with which phosphofructokinase functions, leading to regulation of the rate of ________ as a whole.
glycolysis
carbohydrates can enter cellular respiration, and for the most part, they enter during __________
glycolysis
_________ creates new glucose from different types of fuel sources
glyconeogenesis
in ATP, there are high energy bonds between phosphate groups. These release significant free energy whenever they are broken by a ___________ reaction.
hydrolysis
Protons spontaneously seek to (increase/decrease) the entropy of the matrix.
increase
aerobic pyruvate oxidations and Krebs cycles (directly/indirectly) depend on oxygen.
indirectly
pyruvate oxidation step ___________ depends on oxygen, and it reduces NAD⁺ to NADH.
indirectly
the Krebs cycles (directly/indirectly) depend on oxygen.
indirectly
the processes used to get amino acid byproducts into cellular respiration requires energy, which makes proteins an ________ fuel source
inefficient
The mitochondrial _________ membrane contains the ETC for eukaryotes.
inner
The energy _______ phase begins as glucose enters the cytosol of the cell.
investment
An _________ enzyme modifies glucose-6-phosphate into fructose-6-phosphate (remember, glucose and fructose are isomers of each other).
isomerase
The Cori cycle can convert _______ into _______ at the liver
lactate into glucose
in lactic acid fermentation, NADH transfers its electrons to pyruvate, regenerating NAD⁺. As this occurs, ________/_______ ______ is formed.
lactate/lactic acid
Chylomicrons leave enterocytes and enter small lymphatic vessels that take fats to the rest of the body called ________
lacteals
However, the processes used to get amino acid byproducts into cellular respiration require energy, which makes proteins an inefficient fuel source. The biggest downside for proteins comes from the fact that cells need a pool of amino acids for making the various proteins they use to carry out their functions. Therefore proteins are a _______ _______ in cellular respiration.
last resort
Two carbons (added into the cycle by each acetyl-CoA) ________ as two separate carbon dioxide molecules.
leave
For a triglyceride to enter an adipocyte from a chylomicron, it must again be acted upon by a _______ enzyme, causing it to break down into free fatty acids and monoglycerides. Once inside the adipocyte, the triglyceride will reform.
lipase
Digesting a triglyceride with a lipase is called ________.
lipolysis
The hormone sensitive lipase enzymes create free fatty acids and glycerol molecules via lipolysis. The free fatty acids and glycerols can then travel through the blood via a multitude of ways. ONE way is that they can reform into triglycerides along with proteins, phospholipids, and cholesterol to make different types of _________-.
lipoproteins
Glycerol enters glycolysis or gluconeogenesis at the _________
liver
High-density lipoproteins (HDLs) have a high density of proteins. They are generally considered to be healthy because they take cholesterol away from peripheral tissues and deliver it to the ________
liver
glycogenesis occurs in which organ
liver
hepatocytes contain an enzyme that "undoes" the hexokinase reaction of glycolysis. For this reason, the _______ is the only organ that can release glucose into the bloodstream, allowing other cells to use the glucose as a fuel source.
liver
The _______ stores ____/____ of the body's glycogen, and it is the only organ that can make glucose available to other tissues.
liver stores 2/3
the type of lipoprotein that can end up clogging blood vessels that supply the muscle tissue of the heart - which can lead to a heart attack!
low density lipoprotein (LDL)
FADH₂ carries electrons that are (higher/lower) in energy than the electrons found in NADH.
lower
the whole web of metabolic pathways that occur in a cell at any given time.
metabolism
the alcohols made by lipase can be free glycerol molecules, as well as other types like __________.
monoglycerides
why is it thought that mitochondria were engulfed before chloroplasts? They were present in ______ cells than chloroplasts
more
The Cori cycle transports lactate from the ________, through the bloodstream, and to ______ cells
myocyte to liver cells
another word for muscle cells
myocytes
human muscle cells (____________) have a high energy requirement, so there are many mitochondria in them.
myocytes
spontaneous reactions have (positive/negative) gibbs free energy -∆G
negative
can human red blood cells perform aerobic cellular respiration?
no (Human red blood cells (erythrocytes) do not have mitochondria and thus cannot perform aerobic cellular respiration, so they always ferment.)
anabolic reactions are ____________processes because they require energy input to proceed to the final state.
non-spontaneous
Adenosine triphosphate (ATP) is an RNA ________ ________, meaning it has three phosphates covalently linked to a ribose sugar.
nucleoside triphosphate
In the first step of the Krebs cycle, a two-carbon acetyl-CoA joins four-carbon __________to form six-carbon citrate.
oxaloacetate
after FAD undergoes a reduction to FADH2, the four-carbon molecule transforms back into four-carbon ___________.
oxaloacetate
the ETC operates through a series of _______-______ reactions.
oxidation-reduction (redox)
Before amino acids undergo cellular respiration, they must undergo _______ _______ in the liver.
oxidative deamination
the conversion from fructose-6-phosphate to fructose-1,6-bisphosphate is carried out by an enzyme called _________ (PFK), and it is another irreversible reaction.
phosphofructokinase
in the energy investment phase, glucose gets ___________ via the hydrolysis of one ATP into ADP + Pᵢ.
phosphorylated
Carbohydrates are the body's _______ _______ source
preferred energy source
When it comes to cellular respiration, ______ are the least desirable fuel source.
proteins
in the enterocytes of the small intestine, free fatty acids and monoglycerides enter the cell. Once contained within the enterocyte, the free fatty acids and monoglycerides will reform into triglycerides. Once the triglycerides have reformed, they will pair up with ______,________-, and ________ in the enterocyte.
proteins, phospholipids, and cholesterol
in the Cori cycle, once the lactate is at a hepatocyte, the lactate can oxidize back into ________
pyruvate
pyruvate manipulation is carried out by _________ _________, which is a complex of three interconnected enzymes.
pyruvate dehydrogenase
Lactic acid fermentation regenerates NAD⁺ as NADH by reducing _________ into ________ _______
pyruvate into lactic acid
as the two-carbon molecule undergoes oxidation, NAD+ is (reduced/oxidized) to NADH
reduced
in ATP, the _______ also connects to an adenine nitrogenous base.
ribose
In the case of gluconeogenesis from pyruvate in the Cori cycle, we need an energy investment of ______ ATP.
six
Some evidence for endosymbiotic theory includes ______ similarities and the fact that mitochondria and chloroplasts contain their own circular DNA and ribosomes.
size
catabolic reactions are ____________ reactions because they do not require energy input to proceed.
spontaneous
The amino acid byproducts created via oxidative deamination can enter cellular respiration at various points, depending on the ______ _____ _____.
starting amino acid
When it comes to cellular respiration, proteins are the least desirable fuel source. They are only catabolized when cells are ______ due to unavailability of carbohydrates and fats.
starving
cristae of mitochondria are a part of the inner membrane that increase _____ _____
surface area
the two parts of oxidative phosphorylation work together to synthesize _______ and produce ______
synthesize ATP and produce WATER