Download oxidation reduction

Re cap
5 minutes - write a summary (can use diagrams)
of what you can recall from last weeks lesson.
Learning objectives
● Be able to describe exothermic and endothermic
chemical reactions
● Be able to explain the importance of coupled
chemical reactions in metabolism
● Be familiar with the terms oxidation and reduction
Energy in Chemical Reactions
Energy Content
of products
Energy
Energy
Energy Content
of reactants
Energy Content
of products
progress of
reaction
Energy Content
of reactants
progress of
reaction
Enzymes work by lowering the energy of activation.
Coupled Chemical Reactions
Coupling of exothermic and endothermic reaction
allows energy released by reaction to start another
ATP
Glucose
energy
ADP + Pi
Glucose – 6 - P
OXIDATION
REDUCTION
- Addition of oxygen
- Removal of oxygen
- Loss of hydrogen
- Gaining hydrogen
- Loss of electrons
- Gaining electrons
OILRIG
Oxidation is the loss of electrons; reduction is
the gain of electrons
C6H12O6 + 6 O2
6 CO2
+
6 H2O
Respiration is the oxidation of carbon (glucose)
NAD and FAD are electron acceptors during respiration
NAD+ + e-
NADH + H+
FAD + e-
FADH2
Oxidised or reduced?
+
NAD
+
e
NADH +
+
H
reduced
FAD + e-
FADH2
reduced
Reduced NADH and FADH2 are important as they carry
electrons which power other stages of respiration.
Class activity
Nicotinamide adenine dinucleotide (NAD)
Flavin adenine dinucleotide (FAD)
FAD
FADH2
NAD
NADH
Class activity
Move around the class displaying what you are?
Oxidised or reduced?
How could we develop this idea?
Learning objectives
● Be able to describe exothermic and endothermic
chemical reactions
● Be able to explain the importance of coupled
chemical reactions in metabolism
● Be familiar with the terms oxidation and reduction
FAD
FADH2
NAD NADH
Learning objectives
● Be able to draw a schematic overview of cellular
respiration
● Be able to describe the metabolic pathway from glucose to
pyruvate during glycolysis
● be able to analyse the energy transduction that occurs
during glycolysis
Cell Metabolism
Respiration: overview
Cell Metabolism
Respiration: overview
FERMENTATION
ANAEROBIC
GLYCOLYSIS
Glucose
O2
H2O
AEROBIC
LINK
REACTION
KREB
CYCLE
ELECTRON
TRANSPORT
CHAIN
Glucose
P
P
P
P
P
P
P
P
P
P
Stage 1:
Activation of glucose
By phosphorylation
Glucose
ATP
ATP
ADP
ADP
Phosphorylated glucose
Stage 2:
Splitting of
Phosphorylated
glucose
P
P
Triose phosphate
P
Triose phosphate
P
Triose phosphate
P
Stage 3:
Oxidation of the triose
phosphate
P
NAD+
NAD+
NADH
P
Stage 4:
Production of
ATP
Triose phosphate
P
NADH
ADP +
+ ADP
ATP
ATP
+ ADP
ADP +
ATP
ATP
Pyruvate
Pyruvate
P
P
Yield from
GLYCOLYSIS
Input
Output
Glucose
2 Pyruvate
2 ATP
4 ATP
2 NAD
2 NADH
Learning objectives
● Be able to draw a schematic overview of cellular
respiration
● Be able to describe the metabolic pathway from glucose to
pyruvate during glycolysis
● be able to analyse the energy transduction that occurs
during glycolysis
Learning objectives
● Be able to describe the difference between aerobic and
anaerobic respiration
● Be able to recall which different subcellular compartment
are involved in aerobic and anaerobic respiration
● Be able to explain the biological importance of anaerobic
respiration
Anaerobic Respiration
GLYCOLYSIS
O2
H2O
AEROBIC
Glucose
LINK
REACTION
KREB
CYCLE
ELECTRON
TRANSPORT
CHAIN
O2
GLYCOLYSIS
AEROBIC
Glucose
LINK
REACTION
KREB
CYCLE
H2O
ELECTRON
TRANSPORT
CHAIN
O2
GLYCOLYSIS
AEROBIC
Glucose
LINK
REACTION
KREB
CYCLE
ELECTRON
TRANSPORT
CHAIN
Anaerobic Respiration
FERMENTATION
GLYCOLYSIS
Glucose
Why does Anaerobic
respiration occur?
Anaerobic Respiration
Why does Anaerobic
respiration occur?
● To enable continued glycolysis
● To recycle NAD for glycolysis
NO
● Note, there is
production of ATP (energy)
during anaerobic respiration.
Anaerobic Respiration
Two types of anaerobic respiration
Alcoholic fermentation
Lactic acid fermentation
Alcoholic fermentation
glucose
Producing ethanol from pyruvate
regenerates oxidised NAD and
allows glycolysis to continue
triose
phosphate
NAD
NADH
pyruvate
NADH
ethanal
CO2
NAD
Alcohol
dehydrogenase
ethanol
Lactic acid fermentation
glucose
triose
phosphate
Producing lactate from pyruvate
regenerates oxidised NAD and
allows glycolysis to continue
NAD
NADH
pyruvate
NADH
Oxygen
Debt?
NAD
lactate
dehydrogenase
lactate
Learning objectives
● Be able to describe the difference between aerobic and
anaerobic respiration
● Be able to recall which different subcellular compartment
are involved in aerobic and anaerobic respiration
● Be able to explain the biological importance of anaerobic
respiration
Learning objectives
● Be able to describe the reactions that occur as pyruvate
enters the mitochondria
● Be able to explain the energy transduction during the link
reaction
Aerobic Respiration
O2
GLYCOLYSIS
AEROBIC
Glucose
LINK
REACTION
KREB
CYCLE
H2O
ELECTRON
TRANSPORT
CHAIN
● with oxygen available the pyruvate enters the mitochondria
Aerobic Respiration
AEROBIC
Glucose
LINK
REACTION
O2
H2O
LINK
REACTION
Pyruvate
Coenzyme A (CoA)
NAD
NADH
CO2
Acetyl CoA
● Remember glycolysis produces 2 molecules of pyruvate
per molecule of glucose.
Yield from
LINK
REACTION
Input
Output
2 pyruvate
2 Acetyl CoA
2 CO2
2 NAD
2 NADH
Learning objectives
● Be able to describe the reactions that occur as pyruvate
enters the mitochondria
● Be able to explain the energy transduction during the link
reaction