Unit 3 – Lecture 10
Cellular RespirationCellular Respiration: process used by all
living organisms to make energy in the form of ATP. Equation: C6H12O6 + O2 E + H2O +CO2
for eukaryotic organisms, this takes place in the mitochondria
Cellular Respiration – cont’dTwo Kinds:
Aerobic: describes a process that requires oxygen [Krebs Cycle & ETC]
Anaerobic: describes a process that does not require oxygen [Glycolysis & Fermentation]
Cellular Respiration – cont’dAerobic Respiration AND Anaerobic
respiration BOTH start with GlycolysisGlycolysis: breaks down glucose [6-
carbons] to form pyruvate [3-carbons]glyco – refers to glucose [remember
glycogen?]lysis – to break downtakes place in the cytoplasm
GlycolysisATP used to break glucose [6-C] into
two, 3-Carbon molecules
Glycolysis – cont’dadditional phosphates added to 3-C molecules
makes NADH + H [similar to NADPH except without the phosphate]NADH = electron carrier NADH + H goes to the ETC of CR
Glycolysis – cont’d3-C molecule is stripped of extra phosphates
by other ADP molecules to form two pyruvate moleculespyruvate = another 3-C molecule
Glycolysis – cont’dTO SUM UP: three products of Glycolysis =
ATP [little bit – 2 molecules!]NADH +HPyruvate
Aerobic CR[begins with Glycolysis anyway,
even though that does not require oxygen]Krebs Cycle: produces CO2 and H2O from the
pyruvate & NADH+H [made in glycolysis] takes place inside of the
mitochondrial matrix.Electron Transport Chain
takes place at inner membrane
Krebs Cycleaka Citric Acid Cyclepyruvate from Glycolysis
becomes a 2-carbon compound by releasing CO2
Krebs Cycle – cont’dthat 2-C compound goes through changes
whichproduce ATP [from ADP+P] produce NADH +H
(electron carrier) to be used later in ETC of Cellular Respiration
remember – Photo-synthesis has NADPH [both have the ‘P’]; CR has NADH [no P]
Krebs Cycle – cont’dthat 2-C compound goes through changes
whichproduce FADH2
(another e- carrier)to be used later in the ETC of Cellular Respiration]
this repeats over and over…
Krebs Cycle – cont’dTO SUM UP: products of Krebs =
CO2
ATP [little bit – 1 molecule!!]filled e- carriers
FADH2 NADH +H
ETCe-s from FADH2 and NADH [from Glycolysis &
Krebs] move down proteins in membranecreates NAD+e-s pass
throughthe ETC, releasingE [like in photo-synthesis]
Glycolysis & KrebsNAD+
ETC – cont’dthis moves H+ ions through ion pumps,
forming a gradient of charge & concentration [electrochemical gradient] in the inter-membrane space
Glycolysis & KrebsNAD+
ETC – cont’doxygen combines with the e-s & H from the
carriers to make water opposite of ETC
in photo-synthesis where wesplitwater with the E… we form ithere!
Glycolysis & KrebsNAD+
H2O
ETC – cont’dH+ ions funnel through the ATP Synthase
to make ATP from ADP+P 32-36 molecules!!!
Glycolysis & KrebsNAD+
H2O
ADP + P
ATPSynthase
ETC – cont’dProcesses:
ETCChemiosmosis – ATP Synthesis
Glycolysis & KrebsNAD+
H2O
ETC Chemiosmosis
ADP + P
ATP
Anaerobic Respiration[begins with Glycolysis]Fermentation: recycles the products from
glycolysis [pyruvate and NADH+H] if there is no oxygenno ATP made heretakes place in the cytoplasm of the cell
Fermentationcan take two forms:
lactic acid fermentationpyruvate from Glycolysis lactic acid
uses NADH, producing NAD+ NAD+ then goes back to Glycolysis
lactic acid builds up in your tissues [makes you sore!]
Fermentation – cont’dcan take two forms:
alcoholic fermentationpyruvate from Glycolysis into ethanol
[drinking alcohol] releases CO2 uses NADH, producing NAD+ NAD+ then goes back to Glycolysis
this is how alcohol is made & bread rises [yeast], and how how yogurt, cheese & sour cream are made [bacteria&fungi]
ATP ProductionIf Oxygen Present = Aerobic Respiration
[Glycolysis]Glucose in2 ATP out
ATP ProductionIf Oxygen Present = Aerobic Respiration
[Glycolysis]Krebs Cycle
Oxygen inCO2 out1 ATP out
ATP ProductionIf Oxygen Present = Aerobic Respiration
[Glycolysis]Krebs CycleETC
Oxygen inWater outLOTS of ATP out [32-36]
ATP Production – cont’dIf no Oxygen Present = Anaerobic Respiration
[Glycolysis]Fermentation
If no Oxygen present, only Glycolysis makes ATP.
[questions follow]
Where does glycolysis take place?Where does the Krebs Cycle take place?Where does the ETC
take place?Where does
fermentation takeplace?
What are the foldsin the inner membrane called?
Why is the inner mitochondrial membrane folded into cristae?
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