Chapter 5.3 Flashcards
What does photosynthesis do to carbon dioxide?
Reduces it to glucose
How do plants reduce glucose?
Electrons and hydrogen ions are chemically added to carbon dioxide to produce high energy glucose molecules
What does cellular respiration do to glucose?
Releases the energy in glucose
How does cellular respiration release the energy in glucose?
By oxidizing glucose to carbon dioxide. Electrons and hydrogen ions are removed releasing energy
What is produced in cellular respiration?
Energy, Carbon Dioxide and Water
Which organisms carry out aerobic cellular respiration?
Organisms that live in oxic (oxygen containing conditions)
What is aerobic cellular respiration?
Cellular respiration that requires oxygen to produce ATP
What types of organisms carry out Aerobic Cellular respiration?
Animals, Plants, and many types of Fungi, Protists and Bacteria
What is anaerobic cellular respiration?
Cellular respiration that does not require oxygen to produce ATP
What type of environment does anaerobic cellular respiration take place in?
Environments that are anoxic (no-oxygen)
Which organisms carry out anaerobic cellular respiration?
Some types of bacteria and members of archaea
What is a third pathway for releasing energy from food sources?
Fermentation
What type of process is fermentation?
Anaerobic, but it is not technically classified this way
Where does fermentation occur in animals?
In the muscle cells
What type of reaction is Aerobic Cellular Respiration?
An oxidation reaction
What happens in Aerobic Cellular Respiration?
A series of enzyme-catalyzed reactions transfer electrons from high energy molecules (glucose) to oxygen
Why does cellular respirations begin with?
Glycolysis
Where does Glycolysis occur?
In the cytoplasm of cells
Does Glycolysis require oxygen?
No, it occurs without oxygen is is anaerobic
What does Glycolysis generate?
A small amount of ATP
What is the product of Glycolysis?
A molecule called pyruvate which contains a large amount of energy
What happens when oxygen is not available to Eukaryotic cells when pyruvate is produced?
Then it proceeds to the process of fermentations
What happens to pyruvate when sufficient oxygen is available?
It is transported from the cytoplasm to the mitochondria
What is the functions of Krebs cycle?
Transform the energy in glucose ito reducing power if molecules called NADH and FADH2
What do NADH and FADH2 supply?
High energy electrons to an electron transport system that produces ATP.
What is the role of Glycolysis?
To split glucose into 2 molecules of pyruvate
Why is ATP used at the start of glycolysis?
Energy must be added to start the series of reactions
What type of molecule is pyruvate?
A 3 carbon molecule
What happens after pyruvate is formed?
More reactions occur in which ATP is synthesized and a molecule called NAD+ is reduced to NADH
Why can glycolysis use ATP in the beginning?
Because the amount of ATP that is synthesized (4 molecules) is greater than the amount of ATP that was used to start the process (2 molecules)
What is the net gain from Glycolysis?
2 molecules of ATP
What is the product when Glycolysis is finished?
Two identical 3-carbon molecules of Pyruvate and 2 molecules of ATP
What is the only pathway that a cell can extract energy from glucose if unable to use oxygen?
Glycolysis
What must happen to pyruvate before it can enter the Krebs cycle?
It has to lose a carbon atom in the form of carbon dioxide and the other 2 carbon atoms are bonded to a molecule called coenzyme
What is the product when carbon turns into carbon dioxide and bonds w/ coenzyme before the Krebs cycle?
It reduces NAD+ to NADH
Why is the Krebs cycle called a cycle?
Because the last compound (a four carbon compunds that picks up a group of 2 carbons from acetyl-CoA) must be regenerated so it can pick up 2 more carbon groups
What happens during a complete Kreb cycle?
2 carbon groups are added to the Krebs cycle and 2 carbon atoms are oxidized into carbon dioxide
What is most energy released when carbon atoms are oxidized transformed into?
Reducing power in the form of reduced NADH and FASH2
What is also generated during the Krebs cycle?
An ATP molecule
When are the majority of ATP molecules produced during Aerobic Cellular respiration?
During electron Transport
What happens in the electron transport system in mitochondria?
High energy electrons are are passed to a chain of electron-carrying molecules that are attached to the inner membrane of the mitochondria.
As they are passed from one carrier to another, energy is released.
The energy is used to pump hydrogen ions from the matrix to the intermembrane space
What does the build up of hydrogen ions in the intermembrane space do?
Creates a hydrogen ion concentration gradient
How do hydrogen ions in the intermembrane space diffuse back across the membrane?
Through channels created by the enzyme ATP synthase
What does the enzyme of ATP synthase do?
Uses the energy of the concentration gradient to bind a phosphate group to ADP forming ATP. This is called Chemiosmosis
What does chemiosmosis do in the chloroplast and the Mitochondrion?
Couples the movement of hydrogen ions down their concentration gradient to synthesis of ATP from ADP and phosphate
What is the final electron accepting molecule in the electron transport system?
It accepts electrons and hydrogen ions to create water
When does oxygen take part in aerobic cellular respiration?
The very last set of reactions in electron transport
Why can’t the body survive on only glycolysis?
Because glycolysis does not produce enough energy to sustain the needs of most eukaryotic cells
Where is the majority of ATP produced in aerobic cellular respiration?
In chemiosmosis, using the energy of the hydrogen ion concentration formed by the electron transport system
What type of cellular respiration do prokaryotes use?
Anaerobic cellular respiration
What does anaerobic cellular respiration usually include?
An electron transport system and a concentration gradient to generate more molecules of ATP
Which cellular respiration is more efficient?
Aerobic cellular respiration. Anaerobic cellular respiration provides less molecules of ATP
How many molecules of ATP does aerobic cellular respiration produce?
36
What must serve as an electron acceptor in anaerobic respiration?
Usually an inorganic chemical such as sulfate, nitrate, or carbon dioxide
What are the metabolic pathways in anaerobic cellular respiration called?
Fermentation
Where does fermentation occur?
In the cytoplasm of a cell
What does fermentation include?
Glycolysis and one or two reactions that in which NADH is oxidized to NAD+, by reduction of puruvate
Why is fermentation less efficient at supplying energy?
Because fermentation only produces the amount of ATP that is generated in glycolysis
What do many single cells organisms carry out?
Fermentation
Where does fermentation occur in the body?
Parts of the organism that are in an anaerobic environment. Such as a plant that is partly submerged in water or cells that are deep within a multicellular organism
What are the two types of fermentation?
Lactate fermentation and ethanol fermentation
Which organisms carry out lactate fermentation?
Some single called organisms and som animal cells that are temporarily without oxygen
What happens in lactate fermentation?
Cells use NADH to convert pyruvate to a molecule called lactate in a single step
What results in fermentation when Pyruvate is converted to lactate?
NAD+ is recycled to continue the process
Where does Lactate Fermentation occur in the body?
In muscle cells when they are working strenuously
Why does Lactate fermentation happen in the body?
The demand for energy exceeds what can be produced aerobically. Glycolic increases to where it exceeds oxygen supply. Pyruvare starts to accumulate and cannot or broken down in the Krebs cycle. To sustain glycolysis, the muscle removes excess pyruvate by converting it to lactate
What type of fermentation do organisms that work anaerobically use?
Ethanol Fermentation
How many steps are involved in ethanol fermentation?
2!
What happens in ethanol fermentation?
Pyruvate is converted into a 2-carbon molecule and then to ethanol
What happens while other things are going on in ethanol fermentation?
NADH oxidized
