Ch 9.1: Cellular Respiration and Fermentation Flashcards
How is citrate formed?
the acetyl group of acetyl CoA joins by combining with oxaloacetate
Where is the electron transport chain embedded in eukaryotic cells?
the inner mitochondrial membrane
Where is the electron transport chain embedded in prokaryotes?
the plasma membrane
What is a cytochrome?
carrier proteins in the electron transport chain, which is a protein with heme groups containing an iron atom
What is ATP synthase?
the protein complex, in which the H+ moves into binding sites on the rotor of ATP synthase, causing it to spin in a way that catalyzes phosphorylation of ADP to ATP
What is chemiosmosis?
the use of energy in a H+ gradient to drive cellular work
What is the proton-motive force?
the H+ gradient
What is the sequence of energy throughout cellular respiration?
glucose–> NADH–> electron transport chain–> proton-motive force–> ATP
How much ATP is made in cellular respiration?
about 34% of the energy in a glucose molecule is transferred to ATP, making about 32 ATP (the rest of the energy is lost as heat)
What happens when cellular respiration does not have oxygen?
without oxygen, the electron transport chain will cease to operate, and glycolysis couples with anaerobic respiration or fermentation to produce ATP
How does anaerobic respiration complete cellular respiration without oxygen?
anaerobic respiration uses an electron transport chain with a final electron accepter other than oxygen, H2S (hydrogen sulfide) is made as a by-product instead of H20
What is fermentation?
an extension of glycolysis that oxidizes NADH by transferring electrons to pyruvate or its derivatives
What are two common types of fermentation?
alcohol fermentation and lactic acid fermentation
What is the process of alcohol fermentation?
pyruvate is converted to ethanol in two steps: 1. the first step releases CO2 from pyruvate and 2. the second step produces NAD+ and ethanol
What is the process of lactic acid fermentation?
pyruvate is reduced directly by NADH to form lactate and NAD+ and there is no release of CO2
What are the similarities between fermentation, anaerobic, and aerobic respiration?
all use glycolysis to oxidize glucose and harvest the chemical energy of food, and NAD+ is the oxidizing agent that accepts electrons during glycolysis
What are the differences in the mechanisms used to oxidize NADH to NAD+ for fermentation, anaerobic, and aerobic respiration?
Fermentation: an organic molecule (pyruvate or acetaldehyde) acts as a final electron acceptor
Cellular Respiration: electrons are transferred to the electron transport chain
What are the differences in the amount of ATP produced per glucose molecule for fermentation, anaerobic, and aerobic respiration?
Fermentation: produces 2 ATP by substrate-level phosphorylation
Cellular Respiration: harvests much more ATP by oxidative phosphorylation (32 ATP)
What do obligate anaerobes do?
they carry out fermentation or anaerobic respiration and cannot survive in the presence of O2
What is facultative anaerobes?
cells that can survive using either fermentation or cellular respiration, ex. yeast and bacteria
How are fatty acids broken down in Cellular Respiration?
by beta-oxidation, which yields acetyl CoA, NADH, and FADH2
