Chapter 9 Flashcards
Difference between fermentation and aerobic respiration
Fermentation - partial degradation of sugars or other organic fuel that occurs without the use of oxygen
Aerobic - consumed oxygen as a reactant along with organic fuels
Reactants of cellular respiration
Glucose and oxygen
C6H12O6 + 6 O2
Products of cellular respiration
Carbon dioxide, water, and energy
6 CO2 + 6 H2O + Energy
Difference between oxidation and reduction
Oxidation is loss of electrons
Reduction is addition of electrons
OIL
RIG
When compounds lose electrons, they __ energy; when compounds gain electrons, they __ energy
Require
Release
In cellular respiration, electrons are not transferred directly from glucose to oxygen. Following the movement of hydrogen’s allows you to follow the flow of electrons. What electron carrier is hydrogen transferred to first?
NAD +
It is a coenzyme
What are coenzymes?
An organic cofactor
Describe what happens when NAD + is reduced. What enzyme type is involved?
NADH
What is the function of the electron transport chain in cellular respiration?
A sequence of electron carrier molecules (membrane protein) that shuttles electrons
Electron transport involves a series of electron carriers
Where are these found in eukaryotic cells?
Where are these found in prokaryotic cells?
Inner mitochondrion membrane
Plasma membrane
What strongly electronegative atom, pulling electrons down the electron transport chain, is the final electron acceptor?
Oxygen
Explain how the electron transport chain utilized in oxidative phosphorylation
The steps of the electron transport chain releases energy. This energy is used to phosphorylate (add a phosphate to) ADP to synthesize ATP
What is the meaning of glycolysis? What occurs in this step of cellular respiration?
Behind the degradation process by breaking glucose into 2 molecules of a compound (pyruvate)
Sugar splitting
Where does glycolysis occur in the cell? Is oxygen required?
Glycolysis occurs in the cytoplasm, whether or not oxygen is present
Three steps of the citric acid cycle
The carbonyl group is removed from pyruvate, forming CO2
Electrons are transferred to NAD+, forming NADH
Coenzyme A is attached to carbon fragment, creating a very restive chemical: acetyl coA
Citric Acid Cycle:
How may NADHs are formed?
How many total carbons are lost as pyruvate is oxidized?
The carbons are lost in which molecule?
How many FADH2 are formed?
How many ATPs are formed?
How many times does the citric acid cycle occur for each molecule of glucose?
3 2 CO2 1 1 Twice
Explain what happened (in the citric acid cycle) to each of the six carbons found in the original glucose molecule
Each carbon has been released as CO2
6 CO2
Why is oxygen considered the ultimate electron acceptor?
Oxygen is very electronegative and readily accepts electrons
-pulls electrons towards it
Oxygen stabilizes the electrons by combining with two hydrogen ions to form what?
Water
What are the two electron carrier molecules that feed into the electron transport system?
NADH & FADH2
Explain the overall concept of how ATP synthase uses the flow of hydrogen ions to produce ATP
The flow of H+ ions down their gradient causes the protein synthase to rotate. This rotation activates catalytic sites on the matrix side of the protein to produce ATP from ADP and P
What is the role of the electron transport chain in forming the H+ gradient across he inner mitochondrial membrane?
The electron transport chain uses exergonic flow of electrons from NADH & FAFH2 to pump H+ ions across the membrane from the mitochondrial matrix into the intermembrane soace. This forms an H+ gradient
Relate chemiosmosis and proton-notice force to the process of oxidative phosphorylation
The electron transport chain created an increase an potential energy as it creates the H+ ion gradient. This potential energy creates proton-motive force that allows chemiosmosis to occur. The H+ ions flow down that gradient through ATP synthase, driving the synthesis of ATP
Fermentation allows for the production of ATP without using either __ or any __
Oxygen
Electron transport chain
Alcohol fermentation starts with glucose and yields ethanol. Explain this process
Glucose is broken down to pyruvate, 2 NAD+ are reduced to 2 NADH. In order to recycle the NAD+ to generate more ADP from glucose, pyruvate is converted to acetaldehyde. Acetaldehyde is then reduced to ethanol, gaining electrons from 2 NADH. This oxidizes 2 NADH back to NAD+ so that glycolysis can continue
Lactic acid fermentation starts with glucose and yields lactate. Explain this process
As glucose is broken down to pyruvate, 2 NAD+ are reduced to 2 NADH, generating a net of 2 ATP. In order to continue the breakdown of more glucose molecules, pyruvate is reduced to lactic acid by gaining electrons from 2 NADH. This oxidized 2 NADH back to 2 NAD+ so that it can be reused in glycolysis
What three organic macromolecules are often utilized to make ATP by cellular respiration?
Proteins, carbohydrates, fats
Explain the difference in energy usage between the catabolic reactions of cellular respiration and the anabolic pathways of biosynthesis
In cellular respiration, energy is used to synthesize ATP
In biosynthesis, energy is used from ATP to synthesize more complex molecules
