Cellular Respiration Flashcards
When an electron is transferred from one molecule to another, what happened to the potential energy of the molecules?
Loss in the potential energy of the first molecule and gain in the potential energy of the second molecules.
What are the electron carriers in living systems ?
NAD FAD and NADP
Oxidized form of NAD= NAD+
Reduced form of NAD= NADH
Oxidized form of FAD= FAD+
Reduced form of FAD= FADH2
OxidizedformofNADP=NADP+
Reduced form of NADP= NADPH
These electron carrier molecules can easily be oxidized of
reduced
How are photosynthesis and cellular respiration interdependent?
The photosynthesis and cellular respiration are interdependent.
The products of photosynthesis, carbohydrates and oxygen are used in cellular respiration. Likewise, the byproducts of cellular respiration, carbon dioxide is used during photosynthesis.
Where does glycolysis occur in prokaryotes and eukaryotes?
Glycolysis occurs in the cytoplasm of both prokaryotes and eukaryotes
Does glycolysis use oxygen?
No. Glycolysis does not use ATP and it is anaerobic.
What is the only source of energy in RBCs?
Glycolysis is the only source of ATP in RBCs. Bcuz they are not capable of aerobic respiration. When glycolysis is interrupted, these cells cannot maintain sodium potassium pump and eventually, they die.
What gas does cellular respiration use and what gas does it produce ?
It uses oxygen and produces carbon dioxide.
How does glucose enter into the cell ?
By secondary active transport or glucose transporter GLUT.
What are the by products of glycolysis?
Pyruvate , 4 ATP ( 2 ATP net) and 2 NADH
What is the purpose of 1st step of glycolysis, phosphorylating glucose molecules?
To prevent the glucose from leaving the cell via GLUT transporters. The negatively charged phosphate group does not interact with the hydrophobic interior of the cell membrane.
where does CAC occur?
Occurs in cytoplasm in prokaryotes but occur in the mitochondria matrix in eukaryotes.
What are the by products of CAC?
One ATP or GTP, three NADH and one FADH2
Where does the enzymes that catalyzes the reduction of FAD to FADH2 present?
In the inner membrane of the mitochondria so they can transfer the electrons from FADH2 into electron transport chain directly.
What is the oxidation of pyruvate and where does it occur?
Prior to the CAC, pyruvate from glycolysis are oxidized into acetyl CoA by reducing the NAD+ to NADH It occurs in the mitochondria matrix in eukaryotes and cytoplasm in the prokaryotes.
Why is CAC a closed loop cycle?
The end product of CAC,malate is used to reform oxaloacetate after reaction.
Where does oxidative phosphorylation take place?
It takes place in the inner mitochondria membrane or cristae.
How many complexes are there in the electron transport chain?
4 complexes- 1, 2 , 3 and 4.
Where is electron transport chain located in prokaryotes?
Located in the plasma membrane
What is complex 1 made of?
FMN ( flavin mono nucleotide) and FeS containing protein.
FMN is the prosthetic groups of the complex 1.
Where does complex 2 accept electrons and where does it transfer its electrons to?
It accepts electrons from FADH2 and it sends its electrons to the ubiquinone (Q).
From which complexes does uniquinone accept electrons from?
From complex 1 and 2.
What is the difference between ubiquinone and cytochrome c?
Uniquinone can accept pairs of electrons at a time but cytochrome c can only accept an electron at a time.
What is complex 3 made of?
cytochrome b, FeS containing protein and cytochrome c.
cytochromes contain heme groups as their prosthetic group which can carry electrons instead of oxygen as in haemoglobin.
What is complex 4 made of?
Cytochrome c , cytochrome a, cytochrome a3.
Cytochrome a, a3 contains heme groups and cytochrome a3 have a pair of CuA and one CuB molecules.
They hold the atmospheric oxygen very tightly between heme and Cu molecules until it becomes fully reduced.
How many ATP does one molecule of NADH and FADH2 produce?
1 NADH molecule pumps 3 H+ ions and hence can produce 3 ATP. One molecule of H+ can produce one ATP.
1 FADH2 molecule can pump 2 H+ ions and hence can produce 2 ATP.
How many ATP molecules are produced from glycolysis and cellular respiration?
Glycolysis=2 NADH+2 ATP Oxidation of pyruvate=2NADH
CAC= 6 NADH for one glucose
2 ATP for one glucose
2 FADH2 for one glucose.
Total=38 ATP but variances present and only 30-32 ATP are high end expected.
Why can’t RBC perform aerobic respiration and what kind of fermentation do they perform?
RBCs do not have mitochondria so they cannot perform aerobic respiration. They perform lactic acid fermentation and.
What is the anaerobic respiration of archae called mathanogens?
Methanogens reduces CO2 to CH4.
Which fermentation does not produce gas ?
Lactic acid fermentation
What is alcoholic tolerance for yeast?
Alcoholic tolerance for yeast ranges from 5-21 percent.
When an electron is transferred from one molecule to another, what happens to the potential energy of the molecules?
Loss in the potential energy of the first molecule and gain in the potential energy of the second molecule.
What are the electron carriers in living systems?
NAD, FAD, and NADP.
Oxidized forms: NAD+ , FAD+, NADP+
Reduced forms: NADH, FADH2, NADPH.
How are photosynthesis and cellular respiration interdependent?
Photosynthesis produces carbohydrates and oxygen used in cellular respiration, while cellular respiration produces carbon dioxide used in photosynthesis.
Where does glycolysis occur in prokaryotes and eukaryotes?
Glycolysis occurs in the cytoplasm of both prokaryotes and eukaryotes.
Does glycolysis use oxygen?
No. Glycolysis does not use oxygen and it is anaerobic.
What is the only source of energy in RBCs?
Glycolysis is the only source of ATP in RBCs because they lack mitochondria and cannot perform aerobic respiration.
What gas does cellular respiration use and what gas does it produce?
It uses oxygen and produces carbon dioxide.
How does glucose enter into the cell?
By secondary active transport or glucose transporter (GLUT).
What are the by-products of glycolysis?
Pyruvate, 4 ATP (net gain of 2 ATP), and 2 NADH.
What is the purpose of the first step of glycolysis, phosphorylating glucose molecules?
To prevent glucose from leaving the cell via GLUT transporters. The negatively charged phosphate group does not interact with the hydrophobic cell membrane.
Where does the Citric Acid Cycle (CAC) occur?
In the cytoplasm of prokaryotes but in the mitochondrial matrix of eukaryotes.
What are the by-products of the Citric Acid Cycle (CAC)?
One ATP (or GTP), three NADH, and one FADH2 per cycle.
Where are the enzymes that catalyze the reduction of FAD to FADH2 located?
In the inner membrane of the mitochondria, allowing direct electron transfer to the electron transport chain.
What is the oxidation of pyruvate and where does it occur?
Before the CAC, pyruvate is oxidized into acetyl-CoA by reducing NAD+ to NADH. It occurs in the mitochondrial matrix in eukaryotes and in the cytoplasm of prokaryotes.
Why is the CAC a closed-loop cycle?
The end product, malate, is used to regenerate oxaloacetate.
What is the equation for cellular respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy.
Oxygen is reduced (gains electrons and H+), while glucose is oxidized (loses electrons and H+).
Where does oxidative phosphorylation take place?
In the inner mitochondrial membrane (cristae).
How many complexes are there in the electron transport chain?
Four complexes: I, II, III, and IV.
Where is the electron transport chain located in prokaryotes?
In the plasma membrane.
What is Complex I made of?
FMN (flavin mononucleotide) and iron-sulfur (FeS) proteins.
Where does Complex II accept and transfer electrons?
It accepts electrons from FADH2 and transfers them to ubiquinone (Q).
From which complexes does ubiquinone accept electrons?
Complex I and Complex II.
What is the difference between ubiquinone and cytochrome c?
Ubiquinone can accept pairs of electrons, whereas cytochrome c can only accept one electron at a time.
What is Complex III made of?
Cytochrome b, FeS protein, and cytochrome c. Cytochromes contain heme groups to carry electrons.
What is Complex IV made of?
Cytochrome c, cytochrome a, cytochrome a3. Cytochrome a3 contains heme groups and copper (Cu) molecules to tightly bind oxygen until fully reduced.
How many ATP does one molecule of NADH and FADH2 produce?
1 NADH pumps 3 H+ ions, producing 3 ATP. 1 FADH2 pumps 2 H+ ions, producing 2 ATP.
How many ATP molecules are produced from glycolysis and cellular respiration?
Glycolysis: 2 NADH + 2 ATP
Pyruvate oxidation: 2 NADH
CAC: 6 NADH, 2 ATP, 2 FADH2
Total = 38 ATP (usually 30-32 ATP due to variances).
Why can’t RBCs perform aerobic respiration and what kind of fermentation do they perform?
RBCs lack mitochondria, so they cannot perform aerobic respiration. They perform lactic acid fermentation.
What is the anaerobic respiration of archaea called?
Methanogenesis: Methanogens reduce CO2 to CH4. They are found in the digestive tracts of ruminants (e.g., cows, sheep).
What is the anaerobic respiration of sulfate-reducing bacteria?
They use sulfate (SO4) as their final electron acceptor and are found in coastal sea water.
What is lactic acid fermentation?
Pyruvate is converted to lactate by lactate dehydrogenase. The lactate is transported back to the liver to be metabolized into pyruvate.
What is alcoholic fermentation?
Pyruvate is converted into ethanol through pyruvate decarboxylation and alcohol dehydrogenase activity.
Which fermentation process does not produce gas?
Lactic acid fermentation.
What is the alcoholic tolerance of yeast?
Yeast can tolerate alcohol concentrations ranging from 5% to 21%.
