Chapter 7 Flashcards
Cellular Respiration
acetyl CoA
combination of an acetyl group derived from
pyruvic acid and coenzyme A, which is made from
pantothenic acid (a B-group vitamin)
aerobic respiration
process in which organisms convert
energy in the presence of oxygen
anaerobic
process that does not use oxygen
anaerobic cellular respiration
process in which organisms
convert energy for their use in the absence of oxygen
ATP synthase
(also F1F0 ATP synthase) membraneembedded
protein complex that adds a phosphate to ADP
with energy from protons diffusing through it
chemiosmosis
process in which there is a production of
adenosine triphosphate (ATP) in cellular metabolism by
the involvement of a proton gradient across a membrane
citric acid cycle
(also Krebs cycle) series of enzymecatalyzed
chemical reactions of central importance in all
living cells for extraction of energy from carbohydrates
dephosphorylation
removal of a phosphate group from a
molecule
fermentation
process of regenerating NAD+ with either an
inorganic or organic compound serving as the final
electron acceptor; occurs in the absence of oxygen
GLUT protein
integral membrane protein that transports
glucose
glycolysis
process of breaking glucose into two threecarbon
molecules with the production of ATP and NADH
isomerase
enzyme that converts a molecule into its isomer
Krebs cycle
(also citric acid cycle) alternate name for the
citric acid cycle, named after Hans Krebs, who first
identified the steps in the pathway in the 1930s in pigeon
flight muscles; see citric acid cycle
oxidative phosphorylation
production of ATP using the
process of chemiosmosis in the presence of oxygen
phosphorylation
addition of a high-energy phosphate to a
compound, usually a metabolic intermediate, a protein,
or ADP
prosthetic group
(also prosthetic cofactor) molecule bound
to a protein that facilitates the function of the protein
pyruvate
three-carbon sugar that can be decarboxylated
and oxidized to make acetyl CoA, which enters the citric
acid cycle under aerobic conditions; the end product of
glycolysis
redox reaction
chemical reaction that consists of the
coupling of an oxidation reaction and a reduction
reaction
substrate-level phosphorylation
production of ATP from
ADP using the excess energy from a chemical reaction
and a phosphate group from a reactant
TCA cycle
(also citric acid cycle) alternate name for the citric acid cycle, named after the group name for citric acid, tricarboxylic acid (TCA); see citric acid cycle
ubiquinone
soluble electron transporter in the electron
transport chain that connects the first or second complex
to the third
Dinitrophenol (DNP) is an “uncoupler” that
makes the inner mitochondrial membrane “leaky” to
protons. It was used until 1938 as a weight-loss drug.
What effect would you expect DNP to have on the change
in pH across the inner mitochondrial membrane? Why do
you think this might be an effective weight-loss drug?
DNP affects body weight loss by failing the capacity to construct a proton gradient across the mitochondrial inner membrane due to the incapacity to pump hydrogen ions. As a result the weight reduces.
Explanation
DNP affects body weight loss by failing the capacity to construct a proton gradient across the mitochondrial inner membrane due to the incapacity to pump hydrogen ions. Therefore, it leads to the reduction of pH across the inner membrane of mitochondria and accordingly raises intracellular In addition, protons leak through a mitochondrial membrane which influences ATP production and reduces it. So, a person cannot acquire sufficient energy from their food intake, so their needs for food are declined. Because sufficient ATP cannot be formed, sufficient energy is discharged through heat.
Cyanide inhibits cytochrome c oxidase, a component of the electron transport chain. If cyanide
poisoning occurs, would you expect the pH of the intermembrane space to increase or decrease? What
effect would cyanide have on ATP synthesis?
Cyanide attacks reduces cells ability to use oxygen, which would direct to death.
Explanation:
Cyanide attacks the electron conveyance chain of mitochondria within cells and controls deriving of energy from oxygen.
Thus, pH of the intermembrane space would rise due to the incapacity of pumping electrons into the intermembrane space. Therefore, ATP synthesis would arrest, cells would be incapable to use oxygen, which would direct to death.
Tremetol, a metabolic poison found in the white snake root plant, prevents the metabolism of
lactate. When cows eat this plant, tremetol is concentrated in the milk they produce. Humans who
consume the milk can become seriously ill. Symptoms of this disease, which include vomiting, abdominal pain, and tremors, become worse after exercise. Why do you think this is the case?
Tremetol, a metabolic toxin found in the white snakeroot plant, forestalls the digestion of lactate. When humans drink milk, the lactate is then transferred to the human body. Then humans become unhealthy.
Explanation
The milk includes lactate. When humans drink milk, the lactate is then transferred to the human body. Since the milk already included the metabolic poison, humans become unhealthy. After exercising, the lactate level increases. This would induce the signs of the illness to worsen.
The energy currency used by cells is ________.
ATP
A reducing chemical reaction ________.
adds an electron to the substrate
During the second half of glycolysis, what occurs?
ATP is made.
What is removed from pyruvate during its conversion into an acetyl group?
carbon dioxide
What do the electrons added to NAD+ do?
They go to another pathway for ATP production.
GTP or ATP is produced during the conversion of
________.
succinyl CoA into succinate
How many NADH molecules are produced on each turn
of the citric acid cycle?
Three molecules of NADH are created during two oxidative decarboxylation stages and one dehydrogenation stage.
What compound receives electrons from NADH?
FMN
Chemiosmosis involves ________.
the movement of hydrogen ions across a mitochondrial membrane
Which of the following fermentation methods can occur
in animal skeletal muscles?
lactic acid fermentation
A major connection for sugars in glycolysis is ________.
glucose-6-phosphate
Through triosephosphate isomerase, dihydroxyacetone phosphate is converted to glyceraldehyde-3-phosphate, however it does not come into contact with sugars during glycolysis.
Phosphoenolpyruvate (PEP) is converted to pyruvic acid by pyruvate kinase and also produces ATP (adenosine triphosphate).
Hence, fructose-1,6-bisphosphate, dihydroxyacetone phosphate, and PEP are not the major contacts for sugars in glycolysis. So, the options b, and d are incorrect.
Glucose-6-phosphate is a sugar molecule that is naturally found in cells as most of the glucose that joins the cell is phosphorylated to create glucose-6-phosphate. Thus, in glycolysis, the main relation for sugars is glucose–phosphate.
Beta-oxidation is ________.
the breakdown of fatty acids
Beta-oxidation is a catabolic method that appears in the mitochondrial matrix and concerns the breakdown of fatty acids utilizing two-carbon fragments from the carboxyl end of greasy acids.
The effect of high levels of ADP is to ________ in cellular
respiration.
increase the activity of specific enzymes
The impact of significant degrees of ADP is to expand the movement of the protein.
The control of which enzyme exerts the most control on
glycolysis?
phosphofructokinase
Why is it beneficial for cells to use ATP rather than
energy directly from the bonds of carbohydrates? What
are the greatest drawbacks to harnessing energy directly
from the bonds of several different compounds?
nucleotide (ATP) is that the wellspring of energy to be used and capacity in cells.
Nearly all organisms on Earth carry out some form of glycolysis. How does this fact support or not support the assertion that glycolysis is one of the oldest metabolic
pathways?
Glycolysis is that the initial introduce the breakdown of glucose to separate energy for cell digestion. Glycolysis comprises an energy-requiring stage followed by an energy-delivering stage.
Glycolysis
The destruction of carbohydrates and energy expended into system is identified as glycolysis. Many physiological heart rates be using the energy provided. The metabolism of the glucose unit sugar included most of the energy expended in metabolic activities.
Glucose and Carbon
Fermentation involves two stages. Its initiative are to gather material’s glucose molecules and wear them down as two sugar molecules, each with carbon rings.
The energy from a number of these molecules is taken within the kind of ATP and NADH within the two stages (Reduced Nicotinamide Adenine Dinucleotide).
Cryptoplasm
Glycolysis takes place within the cytosol both of prokaryotes and eukaryotes, although even the steps remain varied in each animal. The organisms that ruled the world eons ago used pyruvate as element of their lifecycle.
Within the lack of oxygen, ,the tactic isdole out . These have revealed that the glucose see another and has evolved. As a result, it effects all bacterial and eukaryotic species. Other key metabolic processes in other species are thought to arise after this glycogen synthesis process
Because they lose their mitochondria during
development, red blood cells cannot perform aerobic
respiration; however, they do perform glycolysis in the
cytoplasm. Why do all cells need an energy source, and
what would happen if glycolysis were blocked in a red
blood cell?
All cells need an energy source to have enough energy to perform some actions in essential processes (e.g. synthesis of macromolecules, pumping ions across membranes).
Red blood cells don’t have mitochondria and they are completely dependent on glycolysis for ATP. Therefore, if the process of glycolysis was blocked in a red blood cell, loss of its membrane potential would occur and that would lead to death.
What is the primary difference between a circular
pathway and a linear pathway?
The difference between a circular pathway and a linear pathway is that in a circular pathway, the reactant and the item are equivalent while in a linear pathway, they are unique.
Additionally, circular pathways contain a solitary chemical reaction while linear pathways can have various others which are autonomous of each other.
How do the roles of ubiquinone and cytochrome c differ
from the roles of the other components of the electron
transport chain?
Ubiquinone andcytochrome are electron carriers that participate justwithin the exchange of electrons between complex proteins.
What accounts for the different number of ATP
molecules that are formed through cellular respiration?
The electron transport chain differs in composition between species, so different organisms will make different amounts of ATP using their electron transport chains.
Explanation
Few tissues except muscle produce the maximum possible amount of ATP from nutrients. The intermediates are used to produce needed amino acids, fatty acids, cholesterol, and sugars for nucleic acids. When NADH is transported from the cytoplasm to the mitochondria, an active transport mechanism is used, which decreases the amount of ATP that can be made. The electron transport chain differs in composition between species, so different organisms will make different amounts of ATP using their electron transport chains.
What is the primary difference between fermentation
and anaerobic respiration?
Fermentation is the chemical breakdown of an organic substrate like glucose by microorganisms like bacteria and yeast, typically giving off effervescence and heat.
Respiration is the set of chemical reactions involved in the production of energy by completely oxidizing food.
Would you describe metabolic pathways as inherently
wasteful or inherently economical? Why?
As a result, one pathway is utilized as the substrate for another lastly this keeps the general metabolism of the body adjusted.
How does citrate from the citric acid cycle affect glycolysis?
Citrate can inhibit phosphofructokinase by feedback regulation and this affects glycolysis.
Explanation
A citrate in the citric acid cycle is formed from oxaloacetate and acetyl-CoA. The citrate can go from the mitochondria to the cytosol. Citrate in the cytosol is a known inhibitor of phosphofructokinase-1, the rate-limiting enzyme in glycolysis. The inhibition of phosphofructokinase-1 by citrate signals enough energy in the system. Therefore, it signals the pathway that it can slow down the oxidation of glucose molecules for energy purposes.
Why might negative feedback mechanisms be more common than positive feedback mechanisms in living cells?
Negative feedback components really control a cycle; it can switch it off, though positive feedback speeds up the interaction, permitting the cell zero influence over it.
Explanation
Negative feedback switches the framework off, making it insufficient in specific substances.
Positive feedback adjust these shortfalls. Positive feedback takes substance sums back to balance while negative feedback produces overabundance measures of the substance.
