Biology - Chapter 7 - Cell Respiration
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the __________.
H+ concentration gradient across the membrane holding ATP synthase
The following are products of oxidative phosphorylation: H2O 28 ATP 2 ATP O2
H2O 28 ATP
In glycolysis, what starts the process of glucose oxidation?
Some ATP energy is used to start the process of glucose oxidation.
Glucose enters into this step of cell respiration:
Step 1: Glycolysis
Oxygen enters into this step of cell respiration:
Step 3: Oxidative Phosphorylation
True or false? The potential energy in an ATP molecule is derived mainly from its three phosphate groups.
True. The three phosphate groups in an ATP molecule carry negative charges that strongly repel each other and give ATP a large amount of potential energy.
How many NADH are produced by glycolysis?
Two NADH molecules are produced by glycolysis.
Two molecules with the chemical formulas C6H12O6 and C6H12O2 are probably
a monosaccharide and a fatty acid. If you had trouble with this question, review the following material: Monosaccharides generally have molecular formulas that are some multiple of the unit CH2O. Glucose (C6H12O6) is the most common monosaccharide. A fatty acid has a long carbon skeleton with a carbon at one end that is part of a carboxyl group (-COOH); the remainder of the skeleton consists of a hydrocarbon chain. The relatively nonpolar C-H bonds in the hydrocarbon chains of fatty acids are the reason fats are hydrophobic.
True or false? The reactions that generate the largest amounts of ATP during cellular respiration take place in the mitochondria.
True. Glycolysis takes place in the cytoplasm, whereas the Krebs cycle and the electron transport chain, which generate the largest amounts of ATP during cellular respiration, take place in the mitochondria.
The following is NOT true about fermentation: it has an electron transport chain it takes place in the absence of oxygen it starts with glycolysis it produces 2 ATP
it has an electron transport chain is false. It doesn't
The following is NOT true about anaerobic respiration: it produces 28 ATP it starts with glycolysis it takes place in the absence of oxygen it has an electron transport chain
it produces 28 ATP, it only produces 2
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
kinetic energy that is released as hydrogen ions diffuse down their concentration gradient
Pyruvate oxidation in eukaryotic cells occurs in the ________.
mitochondria
Carbon dioxide enters into this step of cell respiration:
none. It is a byproduct
During glycolysis....
occurs in the cytosol breaks down glucose into two molecules of pyruvate electron carrier is NADH Net production of 2 ATPs
Pyruvate Oxidation and Citric Acid Cycle:
occurs in the mitochondria matrix oxidizes pyruvate into acetyl CoA, which enters the citric acid cycle Electron carriers are NADH & FADH2 CO2 is formed as a byproduct Net production of 2 ATPs
In cellular respiration, most ATP molecules are produced by _____.
oxidative phosphorylation Submit
Anaerobic respiration:
prokaryotic organisms do this starts with glycolysis in the cytosol utilizes an electron transport chain, but with no oxygen hydrogen sulfide or other byproducts are made net production of 2 ATPs
This end product of glycolysis still contains a lot of the energy that was originally present in glucose:
pyruvate
In fermentation _____ is reduced and _____ is oxidized.
pyruvate ... NADH
Electrons are transferred between ______.
reactants
Cellular respiration is a type of ____.
redox reaction
During alcohol fermentation in yeast, NAD+ is regenerated from NADH by which of the following processes?
reduction of acetaldehyde to ethanol
In glycolysis, ATP molecules are produced by _____.
substrate-level phosphorylation
In the citric acid cycle, ATP molecules are produced by _____.
substrate-level phosphorylation; A phosphate group is transferred from GTP to ADP.
Both eukaryotic and prokaryotic organisms conduct anaerobic respiration.
False, only prokaryotic cells.
Fermentation takes place in the mitochondria.
False, starts in the cytosol
Fats can't be used for making energy, that is why they are only stored in your body.
False, they can be used for energy
This is the chemical formula for aerobic respiration: sugar + oxygen = carbon dioxide + water+ATP
False.
oxidized
One reactant loses electrons
Aerobic respiration using glucose as sugar equation (words):
sugar + oxygen ----> carbon dioxide + water + energy
The following types of organisms can perform fermentation: bacteria humans yeast plants
bacteria humanas yeast
For each glucose that enters glycolysis, _____ acetyl CoA enter the citric acid cycle.
2
How many ATPs are directly produced per molecule of glucose during glycolsis?
2
At the end of just ONE turn of the citric acid (Krebs) cycle, these molecules have been produced:
2 CO2, 3 NADH, 1 FADH2, 1 ATP
The following are products of glycolysis: 2 pyruvate molecules 4 ATP molecules NADH 2 ATP molecules
2 pyruvate molecules NADH 2 ATP molecules
During glycolysis, 2 ____ are required to start the breakdown of glucose into pyruvate?
ATP
The big hydrogen ion concentration between the mitochondrial membranes is used to power
ATP synthase
Glucose equation
C6H12O6
Aerobic respiration using glucose as sugar equation:
C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy (ATP + heat)
The following are products of pyruvate oxidation: O2 CO2 2 pyruvate molecules 2 ATP molecules
CO2 2 ATP molecules
Cellular respiration
Conversion of food into ATP
Which molecule is metabolized in a cell to produce energy "currency" in the form of ATP?
Glucose
How will a healthy individual's ATP production change during an eight-hour fast?
The individual's ATP production will not change significantly. Submit
Fermentation
in absence of oxygen; makes little ATP
In muscle cells, fermentation produces _____.
lactate and NAD+
The final electron acceptor of cellular respiration is _____.
oxygen
In glycolysis there is a net gain of _____ ATP.
2; It takes 2 ATP to produce 4 ATP.
Aerobic Respiration makes around ___ ATP molecules
32 (2+2+[26 to 28])
For each glucose that enters glycolysis, _____ NADH + H+ are produced by the citric acid cycle.
6
How many carbons does glucose have?
6
Into which molecule are all the carbon atoms in glucose ultimately incorporated during cellular respiration?
Carbon dioxide. All of the carbon atoms in glucose are incorporated into carbon dioxide: Two molecules are formed as pyruvate is converted to acetyl CoA, and four molecules are formed during the Krebs cycle.
The following organisms are able to conduct cell respiration: Plants algae animals photosynthetic bacteria
Cellular respiration
The sugars from photosynthesis is broken down into energy via what to make ATP?
Cellular respiration
Which of the following describes the process of glycolysis?
It represents the first stage in the chemical oxidation of glucose by a cell.
The correct sequence of the events of aerobic respiration is:
Glucose - pyruvate oxidation
A man interested in losing weight and increasing his fitness followed a strict diet and exercise regimen for three months. Body fat analysis indicated that the man had lost 7 kg (about 15 pounds) of fat by following this exercise and diet program. What is the most likely form by which the fat left his body?
It was released as CO2 and H2O.
The equation for cellular respiration is: C6H12O6 + 6O2 6CO2 + 6H2O. At what specific point of cellular respiration has glucose been converted from a six-carbon molecule to 6 molecules of CO2?
MAYBE at the end of citric acid cycle?
Since oxygen is not used in fermentation, another electron acceptor must be used so NADH can be converted to what?
NAD+
Key electron carriers (coenzymes) in cell respiration are:
NAD+ who is reduced into NADH FAD+ who is reduced into FADH2
Most of the energy released in glycolysis and the citric acid cycle is sent to the Electron transport chain via
NADH and FADH2
Step three of aerobic respiration
Oxidative phosphorylation (electron transport chain & chemiosmosis)
Light energy is converted into sugars via?
Photosynthesis
Fermentation - things about it
Prokaryotic and Eukaryotic organisms do this starts with glycolysis in the cytosol no electron transport chain, instead NADH is used Alcohol or lactic acid are made as byproducts Net production of 2 ATPs
reduced
The other reactant gains electrons
The oxygen that is required for aerobic respiration ends up what?
being reduced to form water
During intense exercise, as human muscle cells switch from respiration to fermentation, the cells will increase their catabolism of which of the following energy-containing molecules?
carbohydrates only
Metabolic pathways that breakdown molecules and release stored energy are considered to be
catabolic pathways
As sugar is broken down into energy, _______ shuttle electrons from one redox reaction to another.
electron carriers
This step of cellular respiration produces the MOST ATP
electron transport chain
All of the reactions of cellular respiration after glycolysis take place in this eukaryotic organelle:
the mitochondria
Aerobic respiration is _______ for most making ATP
the most efficient
Hibernating animals can burn fuel without generating ATP. What is the purpose of this?
to generate heat while conserving energy
Which of the following is the most important result of the process of cellular respiration in biological systems?
transforming the energy in glucose and related molecules in a chemical form that cells can use for work
In the absence of oxygen, what is the net gain of ATP for each glucose molecule that enters glycolysis?
two ATPs
Due to lack of oxygen, fermentation does not produce this byproduct:
water
The electrons stripped from glucose in cellular respiration end up in which compound?
water
Aerobic respiration
with oxygen; makes lots of ATP
What type of organisms use cellular respiration?
All organisms - both producers and consumers
This molecule doesn't cross the inner membrane of the mitochondrion, meaning that it is both formed and used inside the mitochondrion.
Acetyl-CoA
Fats are another rich source of energy for our bodies. Breakdown of fats requires the fatty acids to be converted to ______ for use in cellular respiration.
Acetyl-CoA
Energy from catabolism provides the energy to form ATP from ADP plus Pi. The breakdown of ATP to ADP plus Pi provides energy for cellular work.
ATP is a molecule that acts as an intermediary to store chemical energy for cellular work. If you had trouble with this question, review the following material: ATP is a renewable resource that can be regenerated by the addition of inorganic phosphate (Pi) to ADP. Energy released by catabolism in the cell is used to phosphorylate ADP, regenerating ATP. Chemical energy stored in ATP drives most cellular work.
In the absence of oxygen, yeast cells perform fermentation. This results in the formation of what?
ATP, CO2, and ethanol
Yeast cells grown anaerobically can obtain energy by fermentation, which results in the production of
ATP, CO2, and ethanol.
Which of these enters the citric acid cycle?
Acetyl CoA is a reactant in the citric acid cycle.
Which of these is NOT a product of the citric acid cycle?
Acetyl CoA; it only enters the citric acid cycle.
Select the correct statement about cellular respiration. Animals carry out cellular respiration whereas plants carry out photosynthesis. Cellular respiration and breathing differ in that cellular respiration is at the cellular level, whereas breathing is at the organismal level. Plants carry out cellular respiration only in organs such as roots that cannot carry out photosynthesis.
Cellular respiration and breathing differ in that cellular respiration is at the cellular level, whereas breathing is at the organismal level.
What does this suggest about the evolutionary relationship of these eukaryotic organelles to prokaryotes? How might the amino acid sequences of the ATP synthases from the different sources support or refute your hypothesis? It suggests that the organelles, mitochondria and chloroplasts, arose from a(n) )_______ relationship with _______ early in evolutionary time. If the ATP synthases arose independently for each cases, i.e., through _______ evolution, you would expect very ______ amino acid sequences.
ENDOSYMBIOTIC bacteria convergent different
Which stage of glucose metabolism produces the most ATP?
Electron transport and chemiosmosis (oxidative phosphorylation) can yield around 26 molecules of ATP.
Which of these is NOT a product of glycolysis? pyruvate FADH(2) ATP NADH
FADH2 is a product of the citric acid cycle.
Which process is not part of the cellular respiration pathway that produces large amounts of ATP in a cell?
Fermentation is an alternate pathway used when oxygen levels are low.
In the process of cellular respiration, what is consumed, and what is produced?
Glucose is consumed, and carbon dioxide is produced.
1st step of aerobic respiration
Glycolysis
Which step of the cellular respiration pathway can take place in the absence of oxygen?
Glycolysis can take place in the absence of oxygen; its product, pyruvate, enters the cellular respiration pathway or undergoes fermentation depending on the availability of oxygen.
You have started to workout, but your respiratory and cardiovascular systems can't provide as much oxygen to your cells as they need. What process will your muscles use to make ATP?
Glycolysis coupled with lactate fermentation?
In order to lose weight and reduce body fat, a friend of yours has decided to eliminate all fat from his diet, while consuming unrestricted amounts of carbohydrates. What do you think of this idea?
It is a bad idea, because if ATP levels are high in cells, excess acetyl-CoA from the metabolism of carbohydrates can be used for fatty acid synthesis.
A glucose molecule is completely broken down to carbon dioxide and water in glycolysis and the citric acid cycle, but together these two processes yield only a few molecules of ATP. What happened to most of the energy that the cell obtains from the oxidation of glucose?
It is stored in NADH and FADH2
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 ... intermembrane space The energy released as electrons, which have been donated by NADH and FADH2, is passed along the electron transport chain and used to pump hydrogen ions into the intermembrane space.
Which of the following statements about the electron transport chain is true?
NADH and FADH2 donate their electrons to the chain. The electrons lose energy as they move down the chain, and this energy is used to create a proton gradient that drives the synthesis of ATP.
The following organisms are able to conduct photosynthesis: Plants algae animals photosynthetic bacteria
Plants algae photosynthetic bacteria
At the completion of glycolysis, this is present
Pyruvate
Step 2 of aerobic respiration
Pyruvate Oxidation and Citric Acid Cycle
In cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. What is the advantage of such an electron transport chain?
The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates.
Identify all correct statements about the basic function of fermentation. The basic function of fermentation is the production of additional ATP by further oxidation of the products of glycolysis. The basic function of fermentation is the production of ethyl alcohol or lactic acid. The basic function of fermentation is the regeneration of NAD+, which allows continued ATP production by glycolysis.
The basic function of fermentation is the regeneration of NAD+, which allows continued ATP production by glycolysis. Submit
In most cells, not all of the carbon compounds that participate in glycolysis and the citric acid cycle are converted to carbon dioxide by cellular respiration. What happens to the carbon in these compounds that does not end up as CO2?
The carbon compounds are removed from these processes to serve as building blocks for other complex molecules.
Which statement about the citric acid cycle is correct?
The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.
Which of the following is true for all exergonic reactions?
The reaction proceeds with a net release of free energy. If you had trouble with this question, review the following material: Chemical reactions are classified based on their free-energy changes. An exergonic reaction proceeds with a net release of free energy, whereas an endergonic reaction is one that absorbs free energy from its surroundings. If a chemical process is exergonic (downhill), releasing energy in one direction, then the reverse process must be endergonic (uphill), using energy.
Cellular respiration is a redox reaction in which sugar is oxidized into CO2
True
Pyruvate oxidation only occurs in the presence of oxygen.
True
Pyruvate Oxidation and Citric acid Cycle oxidizes pyruvate into...
acetyl CoA, which enters the citric acid cycle
Byproducts of fermentation?
alcohol or lactic acid
_________ are defined as organisms that can create their own energy from inorganic sources.
autotrophs
Scientists believe that this phase of cellular respiration is evolutionarily the oldest:
glycolysis?
_________ are organisms that must get their energy from organic molecules produced by other organisms.
heterotrophs
In cellular respiration ______ are oxidized, and _____ is reduced.
energy sources (carbs and fats); oxygen
What are used to make energy?
fats, proteins, and carbohydrates
Food we consume can be used to make energy in our cells via:
fermentation and aerobic respiration
All living organisms are able to utilize _________________.
glycolysis
This stage of cellular respiration can occur with or without oxygen present.
glycolysis
Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?
glycolysis