Chapter 9 - Cellular Respiration & Fermentation Flashcards
Fermentation is…
the partial degradation of sugars that occurs without oxygen (anaerobic)
Aerobic respiration…
consumes organic molecules and oxygen -> yields ATP
Cellular respiration…
the breakdown of glucose to produce ATP, includes both aerobic and anaerobic respiration
Cellular Respiration Equation:
C6H12O6 + 6 O2 (glucose + oxygen) → 6 CO2 + 6 H2O(carbon dioxide + water) + Energy (ATP + heat)
Redox reactions are
chemical reactions that transfer electrons between reactants
oxidation is when (ox)
lost ox :(, the loss of electrons from a substance
reduction is when (read)
ad read B), the addition of electrons from a substance
oxidation and reduction go hand in hand…
the reducing agent-> electron donor
the oxidizing agent-> oxidizes the electron donor
In cellular respiration, glucose is _ and O2 is _
oxidized; reduced
NAD+ is
a coenzyme that functions as an electron carrier, as an acceptor
NADH represents __ that is tapped to synthesize ATP
stored energy
In order to transport electrons to oxygen…
cellular respiration uses an electron transport chain, using energy-releasing steps
The electron transport chain is…
consists of a number of molecules, mostly proteins, built into the inner membrane of the mitochondria of eukaryotic cells-forms a proton gradient to be used in chemiosmosis
oxidative phosphorylation generates _% of ATP
90%, because it is powered by redox reactions
substrate-level phosphorylation is
production of ATP when an enzyme transfers a phosphate group directly from a substrate to ADP
glycolysis (stage 1)
-harvests chemical energy by oxidizing glucose to pyruvate(breaks down glucose)
-occurs in the cytosol
-yields 2 ATP + 2 NADH
glycolysis has two phases:
energy investment: spends ATP
energy payoff: ATP is produced by substrate phos.
pyruvate oxidation (stage 2 pt 1.)
-upon entering the mitochondria (active transport), and processed through the dehydrogenase
acetyl CoA->
oxidized from pyruvate->turns into acetyl coenzyme A
the citric acid cycle(krebs cycle) (stage 2 pt 2.)
-8 steps, in mitochondria
-for every molecule of glucose-> 4 ATPS + 10 NADH
-acetyl CoA is further oxidized + turns into citrate
Oxidative Phosphorylation (stage 3)
During this stage, chemiosmosis couples electron transport to ATP synthesis
_ and _ donate electrons to the electron transport chain, which powers ATP synthesis
NADH & FADH2
Molecules of the electron transport chain are embedded in the inner _ membrane for eukaryotic cells, and _ in prokaryotes
mitochondrial membrane;
plasma membrane
what is chemiosmosis?
energy stored in the form of a hydrogen ion(H+) gradient across a membrane is used to drive cellular work such as the synthesis of ATP
H+ then moves down its concentration gradient back across the membrane, passing through…
the ATP synthase (enzyme that makes ATP from ADP)
About 34% of the energy in a glucose molecule is transferred to ATP, making about…
32 ATP (rest of the energy is lost as heat)
fermentation and anaerobic respiration enable cells to…
produce ATP without the use of oxygen
-without oxygen, the electron transport chain will cease to operate
glycolysis->anerobic respiration/fermentation->produce ATP
The two common types of fermentation are…
alcohol fermentation and lactic acid fermentation
Obligate anaerobes carry…
out fermentation or anaerobic respiration & cannot survive in the presence of O2 :(
yeast and many bacteria are…
faculative anaerobes- they can survive using either fermentation or respiration
For faculative anaerobes, __ is a fork in the metabolic road leading to alternative catabolic routes
Pyruvate
The five stages of cellular respiration are:
- Glycolysis
- Pyruvate Oxidation
- Citric Acid Cycle/Krebs
- Electron Transport Chain
- Chemiosmosis / Oxidative Phosphorulation
the electron transport chain uses and produces:
-uses NADH, oxidized
-produces NAD+
