Cellular Respiration Unit 5 Flashcards
What is the relationship between photosynthesis and cell respiration?
They are in a sense, reverse processes in terms of inputs and outputs, but do not have the exact same steps in reverse
What is cellular respiration?
The oxidation of glucose (and other molecules) and the capture of energy in a form that is useful to the cell
net reaction of aerobic cellular respiration:
C6H12O6+ 6O2–> 6CO2+ 6H2O + energy (ATP)
What are the four(4) processes of cellular respiration?
Glycolysis, Pyruvate oxidation, Citric acid cycle, & Oxidative phosphorylation (electron transport & chemosmosis
What are other functions of cell respiration? (2)
Creates precursors in biosynthetic reactions, and heat (endotherms), waste for exotherms
Where does glycolysis take place?
Cytosol
What structure is of Bacterium is homologous with Eukaryotes?
Interior of bacterium, Cytosol
Describe the process of glycolysis.
It begins the oxidation of glucose; it nets the cell 2ATP (usable energy) and 2NADH (carrier of high energy electrons that can do useful work later)
What are the 3 steps in the oxidation of pyruvate?
- Pyruvate arising from glycolysis is transported to the mitochondrial matrix and decarboxylated (CO2 removed)
- The resulting 2-carbon acetyl fragment is attached to coenzyme A, a molecule that carries acetyl groups from one set of reactions to another
- More NADH (reducing power) is formed by this reaction.
What guides the pyruvate from the cytosol to the Mitochondria?
Transport proteins
What are the four(4) products of the citric acid cycle (Krebs cycle)?
ATP
NADH (reducing power)
FADH2 (reducing power)
CO2 (waste)
During one turn of the citric acid cycle (krebs) what is the ratio of Acetyl group to CO2
1:2 ratio
What is a biochemical cycle? (citric acid)
A set of reactions in which the starting molecule is regenerated ex. Start w/ acetyl, end with acetyl. Constantly reoccurring molecules cyclic
What are the two(2) types of biochemical cycles?
Cyclic (reoccurring molecules), & linear
What is the last process in cell respiration?
Oxidative phosphorylation
What occurs in oxidative phosphorylation?
Electron transport & ATP synthesis
What are the five(5) steps of oxidative phosphorylation?
- Reduced NADH and FADH2 pass their electrons to the electron transport chain in the inner mitochondrial membrane
- The electrons lose energy as they move from electron carrier to electron carrier
- Some of that energy is used to pump H+ions, against their electrochemical gradient, into the inter-membrane space between the inner and outer membrane of the mitochondrion.
- The energy stored in the form of the H+gradient is used by ATP synthase to make ATP.
- The terminal electron acceptor: O2
Why is O2 so important in cell respiration?
Oxidation of glucose, but more specific the terminal electron acceptor of the electron transport chain within the inner mitochondrial membrane
How can ATP synthesis be stopped? (3)
Suffocation- carrier would’t be able to receive anymore electrons (electron transport stops, pumping of protons stop, ATP synthesis)
Poisons- can block electron transport to O2 (similar to suffocation)
Uncoupler molecules- allow electron transport to continue, but dissipate the H+ gradient
Is much ATP stored in cells?
No, not an energy storage molecule
What is thermogenin?
An uncoupling protein that functions as a proton transporter and produces heat (important for when you’re cold) brown fat
What is the function of fermentation?
It allows the NADH that is formed in glycolysis to dump its electrons and cycle back to glycolysis as NAD+, thus keeping glycolysis and its ATP production going
What is fermentation?
Occurs when there is no oxygen; in this event, electron transport and the citric acid cycle cannot take place
What are examples of organisms (2) that can get by via glycolysis from ATP?
Fungi, & yeast
What is pyruvate converted to in fermentation?
It is converted to lactate or ethanol instead of acetyl-CoA.
