Chapter 9 Flashcards
What do catabolic pathways yield?
Catabolic pathways yield energy by oxidizing organic fuels and breaking down complex molecules
Is this breakdown exergonic or endergonic?
Exergonic - it releases energy
What is fermentation?
Fermentation is a partial degradation of sugars that occur without O2
What is aerobic respiration?
Aerobic respiration consumes organic molecules and O2 and yields ATP
Does cellular respiration refer to aerobic or anaerobic?
Cellular respiration includes both aerobic and anaerobic but is used to refer to aerobic because it produces ATP
What are the products of cellular respiration?
Carbon Dioxide and Water is produced as a result of the sugar being oxidized (ATP and heat are transformed from the process)
What occurs in oxidation-reduction reactions?
Redox reactions are chemical reactions that transfer electrons between reactions
What happens in oxidation?
In oxidation, a substance loses electrons
What happens in reduction?
In reduction, a substance gains electrons, or is reduced (the positive charge is reduced)
What is the reducing agent?
The reducing agent is whoever donated the electron (the oxidizer)
What is the oxidizing agent?
The oxidizing agent is the electron receptor (the reducer)
What is oxidized and what is reduced in cellular respiration?
The fuel (glucose) is oxidized to carbon dioxide and O2 is reduced to water
What are the four stages of harvesting energy from glucose?
Glycolysis: breaks down glucose into 2 molecules of pyruvate
Pyruvate Oxidation: the prep step
Citric Acid Cycle: completes breakdown of glucose
Oxidative Phosphorylation: accounts for most of ATP synthesis
How many molecules of ATP are produced for each molecule of glucose?
up to 32 atp
What happens in glycolysis?
Glycolysis (sugar splitting) breaks down glucose into two molecules of pyruvate, it occurs in the cytoplasm
What does glycolysis harvest and oxidize?
Glycolysis harvests chemical energy by oxidizing glucose to pyruvate
What is formed by substrate-level phosphorylation?
A smaller amount of ATP is formed in glycolysis and the citric acid cycle by substrate-level phosphorylation
What is substrate-level phosphorylation?
Formation of ATP from ADP and a phosphorylated intermediate
Where does the Krebs cycle occur?
in the mitochondria
What does the citric acid cycle do?
The Krebs cycle and TCA (tricarboxylic acid) cycle completes the breakdown of pyruvate to CO2
What does the citric acid cycle oxidize?
The cycle oxidizes organic fuel derived from pyruvate to generate 1 atp, 3 nadh, and 1 fadh2 per turn
What is chemiosmosis?
Chemiosmosis is the energy-coupling mechanism , it is the use of energy in a H+ gradient to drive cellular work
how does electron transfer occur in the electron transport chain?
electron transfer in the electron transport chain causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space
What is a proton-motive force?
The H+ gradient is referred to as a proton-motive force which emphasizes its capacity to do work
What is the proton-motive force?
it is an electrochemical gradient, 85% of the proton motive force is derived from the electric or charge gradient
What is H+ attracted to according to the matrix?
H+ is attracted to the opposite negative charge in the matrix
Where is there a greater concentration of H+?
in the intermembrane space, there is a greater concentration of H+, which causes protons to follow lower concentration in the matrix
how does energy flow in cellular respiration?
glucose - NADH - electron transport chain - proton motive force - ATP
Match cellular respiration to its terms
Cellular respiration releases energy, so it is spontaneous, it is catabolic, is exergonic, and has a negative delta G
how many protons have to pass through ATP synthase for 1 atp to be synthesized?
4 protons
How many electrons are required to reduce a single atom of oxygen?
2 electrons are required to reduce a single atom of oxygen
how many protons are translocated across the membrane through ATP synthase for each pair of electrons that pass through the ETC?
10 protons
what is the P/O ratio?
2.5
what is the ratio when referring to NADH?
1.5
What allows cells to produce ATP without oxygen?
without O2, glycolysis will couple with anaerobic respiration or fermentation to produce ATP
How does anaerobic respiration work?
Anaerobic respiration uses an electron transport chain with a final electron accepter other than O2, for example sulfate
How does fermentation work?
Fermentation uses substrate-level phosphorylation instead of an electron transport chain to generate ATP
What are the two common types of fermentation?
Alcohol fermentation and lactic acid fermentation
What is produced in alcohol fermentation?
pyruvate is converted to ethanol and ethanol is produced through the release of CO2
What is produced in lactic acid fermentation?
pyruvate is reduced by NADH, forming lactate as an end product with no release of CO2 (used to generate ATP when oxygen is scarce)
products of lactic acid fermentation in numbers***
2 atp, 2 pyruvate, 2 molecules of lactic acid, 2 NAD+
products of alcohol fermentation in numbers***
What is deamination?
When the first amino group must be removed
What must happen to proteins to be apart of glycolysis or citric acid cycle?
Proteins must be digested to amino acids which can feed glycolysis or the citric acid cycle
What are fats digested to?
Fats are digested to glycerol and fatty acids
How are fatty acids broken down?
Fatty acids are broken down by beta oxidation and yield acetyl CoA
what does glycolysis accept?
a wide range of carbohydrates: sugars from carbs, glycerol from fats, and some amino acids from proteins entering as pyruvate (pyruvate oxidation)
