Micro Chapter 10 Flashcards
What are the three processes that cells use to make ATP?
- Phototrophy
- Respiration
- Fermentation
What are the two mechanisms that occur during respiration?
Substrate level phosphorylation and oxidative phosphorylation
What mechanism does fermentation use?
Substrate level phosphorylation only
What is substrate level phosphorylation?
ATP is synthesized directly from energy rich intermediates; the ETC is not involved
What is oxidative phosphorylation?
ATP is synthesized as the result of the ETC driven by the oxidation of a chemical
What is chemiosmosis?
The electron flow of the ETC generates a proton motive force which fuels ATP production
What is the source of the electrons that flow through the ETC?
The electron donor
What does pumping H+ across the membrane create?
H+ gradient
What does an H+ gradient create?
A proton motive force
What does the proton motive force create?
Potential energy that fuels ATP production
What is the initial electron donor of a chemoorganotroph?
Organic electron donors like glucose
What is the initial electron donor of a chemolithotroph?
Inorganic electron donor like H2
What is the TEA for aerobic respiration?
Oxygen
What is the TEA for anaerobic respiration?
Anything but O2 - NO3, SO4
What molecule gets respired during respiration?
The electron donor
What is glucose completely oxidized to during aerobic respiration?
CO2
What are the three steps of aerobic respiration?
- Glycolysis
- Intermediate stage
- Krebs cycle
What are the three names for the last step of aerobic respiration?
Krebs cycle, TCA, Citric acid cycle
What is the equation for the aerobic respiration of glucose?
6O2 + C6H12O6 –> 6CO2 + 6H2O + ATP
Where does glycolysis occur?
The cytoplasm
What is the most common pathway used during glycolysis (two names)?
Embden-Meyerhof pathway - the pyruvate pathway
Does glycolysis need oxygen to occur?
No, it occurs in the presence or absence of oxygen
What are the two steps of glycolysis?
The initial 6 Carbon step and the secondary 3 Carbon step
What happens during the initial 6 carbon step of glycolysis?
ATP is used to phosphorylate glucose twice, resulting in a glucose molecule with a high energy phosphate on each end
The 6 carbon glucose then splits into two 3 carbon molecules
What happens during the second 3 carbon step of glycolysis?
The 3 carbon molecules are oxidized, substrate level phosphorylation occurs to produce ATP
What molecule acts as the electron acceptor during the second step of glycolysis?
NAD is reduced to NADH+
What is the net gain of glycolysis?
2ATP, 2NADH+, 2 pyruvate
What is the fate of pyruvate?
It continues on in respiration and is respired fully to CO2
What do the carbon molecules look like in the second step of glycolysis before SLP?
P~CCC CCC~P
~P=high energy bond that is broken and phosphate used to order to form ATP
What is the formula for glycolysis?
Glucose + 2ADP + 2P(i) + 2NAD+ –> 2 pyruvate + 2ATP + 2NADH + 2H+
What happens to pyruvate during the intermediate stage of glycolysis?
2 Pyruvate yields 2 acetyl coA
What steps occur during the intermediate stage of glycolysis?
The decarboxylation step and oxidation step
What happens during the decarboxylation step of the intermediate stage?
The 3 carbon pyruvates turn into 2 carbon acetates and 2 CO2 are released (per glucose)
What happens during the oxidation step of the intermediate stage?
Acetate is oxidized and NAD+ is reduced to NADH; Coenzyme A is attached to the acetate to form acetyl coA
What happens at the end of the intermediate stage of glycolysis?
The 2 acetyl coA formed continue onto the Krebs cycle
Where does the TCA occur?
The matrix of the mitochondria in eukarya and the cytoplasm in prokarya