Chapter 7 Flashcards
What is the point of cellular respiration? How would you define “respiration” here, in contrast to its everyday usage
Process by which energy is harvested
-oxidation of organic compounds to extract energy from the chemical bonds
How is the process of extracting energy in our bodies similar to how internal combustion engines work?
Engines need some source of ignition to get the engine to fire and begin breaking bonds for energy, our body needs enzymes to catalyze reactions and then we break down chemical bonds (mainly C-H in carbs or C-O in fats) for energy
What is a redox chemical reaction?
a reaction in which every atom lost through oxidation is by another atom or molecule through reduction
oxidation - loss of electrons, charge increases
reduction - gain of electrons, charge decreases
How do enzymes contribute to a redox reaction?
Enzymes lower the activation energy and help the reactions to proceed in both directions because it is not consumed
Adenosine Triposphate (ATP) can be generated in two fundamentally different ways. Describe the difference between substrate-level phosphorylation and oxidative phosphorylation.
Substrate Level Phosphorylation - transfer of a phosphate group form a molecule directly to ATP, ATP–>ADP = -Delta-G, ADP–>ATP = +Delta-G, source of the majority of ATP produced in aerobic respiration
Oxidative level phosphorylation - 2 part process that reduces oxygen to water and then makes ATP, makes ATP using ATP synthase enzyme (requires redox reactions), rotational energy converted to energy in ATP
Make a table. You will be making a table as an exam question. Define the starting and endpoints for: glycolysis, transition step, Krebs cycle, electron transport chain. What molecules enter each step? What molecules result from each?
See notes
Where do the processes listed in question 5 occur? Add this to your table above. This will also be an exam question.
Substrate-Level = occurs during glycolysis and the Krebs cycle
Oxidative = Inner membrane of mitochondria
Examine Figure 7.6. Account for ATP usage and generation by following the phosphate groups as they are used in priming and substrate-level phosphorylation.
2 phosphates from ATP added to 6C glucose, molecule splits into 3C sugars, inorganic phosphate is added to each, transfer a phosphate to turn ADP into ATP (4 new ATP)
Net yield - 2 ATP and 2 NADH
How does dinitrophenol (DNP) affect cellular respiration? What is an uncoupled by its presence?
DNP acts as an uncoupler in oxidative phosphorylation, ETC requires ATP synthesis-except in the presence of DNP, where O2 continues to be consumed, though no ATP is being made
- uncouples oxygen consumed and ATP synthesized
- mitochondria are said to be uncoupled, pH is balanced in/out of the cell
During aerobic respiration glucose is completely degraded, leaving CO2, H2O, and potential energy. Make a chart that accounts for the activated carriers that are generated (ATP, NADH, and FADH2) and account for the total number of ATP created.
Glucose –> c6h12o6 + co2 +h2o + potential energy
ATP - 2
NADH - 2
FADH2 - 0
What is the point of fermentation? Why are some organisms unable to carry out aerobic respiration?
important in the role of metabolism of most organisms
When oxygen is unavailable fermentation can make use of organic molecules and can accept electrons
NADH must be oxidized to NAD+ for glycolysis to happen
Why would a eukaryotic organism carry out fermentation? How does this process differ in prokaryotes versus eukaryotes?
EU- lactic acid fermentation
PRO - ethanol fermentation
fermentation aids in metabolism and when o2 isn’t available
