Cellular Respiration Flashcards
The totality of an organism’s chemical reactions. The cells extract energy and apply it to perform work
Metabolism
Starts with a specific molecule
Ends with a product
Metabolic pathway
Consume energy to build complex molecules
from simpler molecules
Anabolic pathway
Release energy by breaking complex molecules into simpler compounds
Catabolic pathway
Transfer of electrons during chemical reactions releases energy stored in organic molecules
The released energy is ultimately used to synthesize ATP
Redox Reactions
Substance loses electron
Oxidation
Substance gains electron, Amount of positive charge is reduced
Reduction
Electron donor
Reducing agent
Electron acceptor
Oxidizing agent
During cellular respiration, what happens?
fuel is oxidized and oxygen is reduced
C6H12O6+602+ 6CO2+ 6H2O+ Energy (ATP + heat)
Cellular respiration
Includes both aerobic and anaerobic respiration, but often used to refer to aerobic respiration
Carbohydrates, fats, and proteins are all consumed as fuel
Helpful to trace cellular respiration with glucose
Cellular Respiration
Key player in cellular respiration
Energy source for all cells Considered as the “energy currency” of the cell
Releases large amounts of energy when converted to adenosine diphosphate (ADP)
Adenosine triphosphate (ATP)
NAD+
Nicotinamide adenine dinucleotide
NADH
nicotinamide adenine dinucleotide + hydrogen
FAD or FADH2
Flavin adenine dinucleotide
3 Stages of Cellular Respiration
Glycolysis, Citric Acid Cycle, Oxidative Phosphorylation
1st, Breaks down glucose into 2 molecules of pyruvate
Glycolysis
2nd, Completes the breakdown of glucose
Citric Acid Cycle
3rd, ATP synthesis
Oxidative Phosphorylation
presence of oxygen, pyruvate enters mitochondrion
Oxidation of glucose is completed
Pyruvate is converted to acetyl Coenzyme A (acetyl COA)
The cycle oxidizes organic fuel derived from
pyruvate
1ATP
3 NADH
1 FADH2
Krebs Cycle
Citric Acid Cycle
Tricarboxylic Acid Cycle
Krebs Cycle
Citric Acid Cycle
Tricarboxylic Acid Cycle
product
1ATP
3 NADH
1 FADH2
Krebs Cycle
Citric Acid Cycle
Tricarboxylic Acid Cycle
how many steps
has 8 steps, each catalyzed by a specific enzyme
NADH and FADH2 produced by the kreb’s cycle relay electrons extracted from food to the
electron transport chain
ETC occurs at the cristae of the mitochondrion
Most of the chain’s components are proteins
Carriers alternate in reduced and oxidized states as they accept and donate electrons
Electrons drop in free energy as they go down the chain and are finally passed to oxygen, forming water
Oxidative Phosphorylation
Use of energy in a H* gradient to drive cellular work
Electron transfer in the ETC causes proteins to pump H* from the mitochondrial matrix to the intermembrane space
H’ moves back across the membrane, passing through the protein complex, ATP synthase
ATP synthase uses the exergonic flow of H to drive phosphorylation of ATP
Chemiosmosis
During cellular respiration, most energy flow in this particular sequence
Glucose + NADH → ETC → Proton-motive Force → ATP
work that they need to do before producing atp
Proton-motive Force
glycolysis produces how many atps
2 atps
citric acid cycle produces how many atps
2 atps
Oxidative phosphorylation (ETC + Chemiosmosis) how many atps
26 to 28 atps
Most cellular respiration requires ______ to produce ATP
Without the presence of ______, ETC will not push through
oxygen
_____ will couple with anaerobic
respiration or fermentation to produce ATP
Glycolysis
Uses etc with a final electron acceptor other than oxygen, uses sulfate
Anaerobic respiration
Uses substrate level phosphorylation instead of ETC to produce ATP (anaerobic respiration)
Fermentation
Yeast and many bacteria
Can survive using either fermentation or cellular respiration
Pyruvate is a fork in the metabolic road that
leads to two alternative catabolic routes
Facultative anaerobes
Carry out fermentation, cannot survive in the presence of oxygen
Obligate anaerobes
Pyruvate is converted to ethanol in 2 steps Release of carbon dioxide
Produce ethanol
o Uses yeast
o Brewing, winemaking, baking
Alcohol fermentation
Pyruvate is reduced to NADH
End product: lactate
No carbon dioxide is released
Process where fungi or bacteria are used to make cheese and yogurt
Lactic acid fermentation
Human muscle cells use ______ fermentation to generate ATP when oxygen is
scarce
lactic acid
funnel electrons from many kinds of organic molecules into cellular respiration Glycolysis accepts a wide range of carbohydrates
Catabolic pathways
must be digested to amino acids
Proteins
can also feed glycolysis or the Krebs cycle
Amino groups
Used in generating acetyl CoA Broken down by beta oxidation
Fatty acid
fats that is used for Glycolysis
Glycerol
