Chapter 9: Cellular Respiration Flashcards
What is Fermentation?
A partial degradation of sugars that occur without O2
Cellular respiration includes both…
aerobic and anaerobic respiration
Aerobic respiration…
Definition
Consumes organic molecules and oxygen and yields ATP
Anaerobic respiration is similar to aerobic respiration but…
It consumes compounds other than oxygen
What is the reaction for Cellular Respiration?
C6H12O6 + 6 O2 —> 6 H2O + energy (ATP + heat)
The breakdown of organic molecules is?
Exergonic
The transfer of ____ during a chemical reaction _____ _______ stored on organic molecules
Electrons
Releases energy
The release of energy is ultimately used to synthesize..
ATP
Oxidation-reduction reaction are also known as?
Redox reactions
What are redox reactions?
Chemical reactions that transfer electrons between reactant
In oxidation…
A substance loses electrons
Is oxidized
In reduction…
A substance gains electrons
Or is reduced ( the amount of positive charges)
Na + Cl —-> Na+ + Cl-
What’s oxidized? Reduced?
Na becomes oxidized
Cl becomes reduced
Reducing agent is a/an..
Electron donor
Oxidizing agent is a/an…
Electron receptor
Some redox reactions do not transfer electrons but…
Example.
Change the electron sharing in covalent bonds
Ex: methane and O2
Methane and O2 reaction.
What’s oxidized? Reduced? How?
CH4 + 2 O2 ——> CO2 + Energy + H2O
Methane is oxidized to carbon dioxide
Oxygen is reduced to water
During cellular respiration what is oxidized and reduced?
The fuel is oxidized (such as glucose)
Oxygen is reduced
Oxidation of glucose is carried out by?
Enzymes called Dehydrogenases
What does dehydrogenase need the help of to oxidize glucose?
Coenzyme
Such as NAD+ and FAD
What IS the oxidized state of NADH?
NAD+
What does NADH represent?
Stored energy that is tapped to synthesize ATP
NADH passes the electron to…
The electron transport chain
What are the stages of cellular respiration?
Glycolysis
The citric acid cycle
Oxidative phosphorylation
Glycolysis
Breaks down glucose into 2 molecules of pyruvate
Where does Glycolysis occur?
In the cytoplasm
Glycolysis can take place..
In both the presence and absense of oxygen
The citric acid cycle does what?
Completes the breakdown of glucose
The citric acid cycle occurs in…
In the presence of?
the mitochondrial matrix
In the presence of oxygen
Oxidative phosphorylation occurs in…
The inner mitochondrial membrane
Oxidative phosphorylation
Accounts for most Id the ATP synthesis
Oxidative phosphorylation is powered by?
Redox reactions
A small amount of ATP is formed in glycolysis and The citric acid cycle by?
Substrate-level phosphorylation
2 major phases of Glycolysis
Energy investment phase
Energy payoff phase
Energy investment phase
2 ATP is used
Energy payoff phase
4 ATP formed
2 NADH + 2 H+
2 pyruvate + 2 H2O
What is the net of Glycolysis?
Glucose –> 2 pyruvate + 2 H2O
4 ATP - 2 ATP used –> 2 ATP
2 NAD+ + 4e- + 4H+ –> 2 NADH + 2 H+
What does acetyl CoA do?
Links The citric acid cycle to Glycolysis
Pyruvate enters the _____ in the presence of ______
Mitochondrion
Oxygen
What has to happen before The citric acid cycle can being?
Pyruvate must be converted to acetyl CoA
Where does The citric acid cycle take place?
Mitochondrial matrix
Another name for the Citric Acid Cycle
Krebs cycle
What happens in the Citric Acid cycle?
What is the result?
The cycle oxidizes organic fuel derived from pyruvate.
generating 1 ATP, 3 NADH, 1 FADH2
How does the acetyl group join the cycle?
By combining with oxaloacetate. Forming citrate
The next 7 steps of the citric acid cycle…
Decompose the citrate back to oxaloacetate, making the the process a cycle
Where is NADH and FADH2 produced? and what do they do?
There were producer from the cycle and they relay extracted electrons to the electron transport chain
What are the 2 parts of oxidation phosphorylation?
Electron transport chain
Chemiosmosis
Where is the electron transport chain located?
On the cristae of the mitochondrion
What does the electron transport chain mostly consist of?
Proteins in multiprotein complexes
What happens in the electron transport chain?
NADH or FADH2 results on NAD+ and FAD
Electrons are passed through a Number a proteins to O2
What is the final electron acceptor?
Oxygen
Chemiosmosis is also known as…
The energy-coupling mechanism
What is chemiosmosis?
The use of energy in a H+ gradient to drive cellular work
The H+ gradient us referred to as a…
Proton-motive force
ATP synthase uses ____ to drive __________ which is a _________
The exergonic flow of H+
phosphorylation of ATP
endergonic reaction
How many ATP is produced during cellular respiration?
About 38 ATP
Energy flow during cellular respiration
Chart
Glucose –> NADH –> electron transport chain –> proton-motive force –> ATP
In the absence of oxygen, glycolysis couples…
with fermentation or anaerobic respiration to produce ATP
Anaerobic respiration uses..
Example?
An electron transport chain with an electron acceptor other then oxygen
Example: sulfate
What is the electron acceptor in fermentation?
Pyruvate
What does fermentation use instead of an electron transport chain to generate ATP?
Phosphorylation
2 types of fermentation
Alcohol
Lactic acid
Fermentation consists of what processes…
Glycolysis plus reactions that regenerate NAD+
Fermentation produces ___ ATP per ______
2
Glucose molecule
What’s the difference between fermentation and aerobic respiration?
They have different final electron acceptors
Obligate anaerobes
Carry out fermentation or anaerobic respiration
Cannot survive in the presence of oxygen
Facultative anaerobes
Organisms they can survive using either fermentation or cellular respiration
