Note!
Please see 3.7 Cell Respiration Core prior to using this presentation.
Assessment Statements
8.1.1 State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.
8.1.2 Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.
8.1.3 Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs.
8.1.4 Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.
8.1.5 Explain oxidative phosphorylation in terms of chemiosmosis.
8.1.6 Explain the relationship between the structure of the mitochondrion and its function.
8.1.1
State that oxidation involves the loss of electrons from an element, whereas reduction involves a gain of electrons; and that oxidation frequently involves gaining oxygen or losing hydrogen, whereas reduction frequently involves losing oxygen or gaining hydrogen.
OILRIG
Oxidation Is LossReduction IsGain
Loss and gain of what?
Oxidation Reduction
XX
X+X+X
X X
X X
X
X+ e-
+ O2O O
H + H+ H
electrons
+ e-
oxygen
+ O2
hydrogen
+ H+ X
Respiration involves oxidation and reduction.
An organic compound (glucose) is oxidised
while ADP is reduced to ATP
In cell processes biochemical processes
are coupled to the oxidation of ATP to ADP
8.1.2
Outline the process of glycolysis, including phosphorylation, lysis, oxidation and ATP formation.
Aerobic respiration, gives a higher yield of
ATP.
ADP + Pi
ATP
Aerobic respiration
glycolysis link reaction
Kreb’s cycle
electron transport chain
oxidative phosphorylation
Glycolysis (sugar splitting)
CC
CC
C C C C
C
CC
CC
C C C C
C
CC
C
CC
C
Glucose 6C
PP
P
P
CYTOPLASM
ATP
ADP + Pi
phosphorylation
lysis
oxidation
2 x 3C pyruvate
NAD+
NADH+ + H+
Phosphorylation
2 ATP
2 ADP + Pi
Energy
Time
There is an increase in
energyPhosphorylation uses 2 ATP to add 2 phosphate groups to glucose.
This makes the glucose molecule more unstable so it becomes easier to break bonds.
The phosphate groups also allow the hexose bisphosphate to bind more effectively with its enzyme.
Lysis
hexose diphosphate
triose phosphate
Triose phosphate or TP is an intermediate in many biochemical reactions.The phosphate groups help the TP to bind to its enzyme.
Oxidation (ATP formation)
NAD+
NADH+ + H+
2 ADP + Pi
2 ATP
There are 2 TP molecules made from each glucose.
A total of 4 ATP molecules are made.
But, we used 2 during phosphorylation.
So, we have a net production of 2 ATP
reduction oxidation
What is NAD+?
Watch the video and then summarise of the key points of glycolysis
Summary
Takes place in the _________
No _________ needed
6C ________ is converted into 3C _________
__ ATP made and __ ATP used
Net gain
2 ATP
2 NADH+ + 2H+
2 3C pyruvate
cytoplasmoxygen
glucose pyruvate
4 2
8.1.3
Draw and label a diagram showing the structure of a mitochondrion as seen in electron micrographs.
8.1.6
Explain the relationship between the structure of the mitochondrion and its function.
Mitochondria
Site of aerobic respiration
Pyruvate is further oxidised to release more ATP.
Only found in eukaryotic cells.
Cells that need a lot of energy will have many mitochondria ( liver cell) or can develop them under training (muscles cells).
Features of mitochondria
Surrounded by a double membrane.
Inner membrane folded to form 'cristae'. LSA for ATP production.
Space between the two membranes which is narrow creating a place to concentrate H+
The inner space is called the matrix.
It contains the enzymes needed for respiration.especially those of the Kreb’s cycle.
An example of compartmentalisation (isolation of substances needed for a particular function)
Mitochondria also contain some of their own DNA (mDNA). http://genome.wellcome.ac.uk/doc_WTD020876.html
PPQ Review
(a) Draw a labelled diagram showing the structure of a mitochondrion as seen in an electron micrograph (4)
(b) Explain the relationship between the structure of the mitochondrion and its function (3)
(a) Award marks for any of the following clearly drawn and correctly labelled.
cristae;
inner membrane;
outer membrane;
intermembrane space;
matrix;
ribosomes;
DNA; 4 max
(b) cristae provide surface area for oxidative phosphorylation;
inner membrane contains electron transport chains/ATP synthase (which
carry out oxidative phosphorylation);
outer membrane separates the mitochondrion from the rest of the cell;
mitochondrial DNA/ribosomes make (mitochondrial) proteins;
small volume intermembrane space allows for higher concentration
of protons;
matrix has enzymes for the Krebs cycle; 3 max
8.1.4
Explain aerobic respiration, including the link reaction, the Krebs cycle, the role of NADH + H+, the electron transport chain and the role of oxygen.
Link Reaction
CoA
NAD+
NADH + H+C
CO2
C C
CoA
Acetyl CoA
Decarboxylation - removal of carbon from the pyruvate
Carbon forms carbon dioxide
2C Acetyl group binds temporarily with Coenzyme A
Kreb’s Cycle
C C
CC C C
CC C C C C
citric acid
CC C C C
NAD+
NADH + H+
C CO2
CC C C
NAD+
NADH + H+
C
CO2
NAD+
NADH + H+
FADFADH2
ADP + Pi
ATP
This is a metabolic cycle.
Each step requires enzymes to reduce the activation energy.
The reactions take place in the mitochondrial matrix.
This reaction occurs within the matrix where each intermediate becomes the substrate for the next step.
Watch this:
8.1.5
Explain oxidative phosphorylation in terms of chemiosmosis.
Watch these:
Task
Reorder the sentences in the booklet to explain the process of chemiosmosis
(answers on the next page)
The inner membrane is folded into cristae and
embedded in this membrane are proteins
which form an electron transport chain
Reduced NAD+ and FAD are oxidised releasing electrons and H+ ions.
The electrons are passed along the chain while the
H+ are pumped by the membrane proteins into the inner membrane space.
These H+ ions accumulate and their concentration increases.
When they diffuse back to the matrix they pass through
a membrane protein called ATP synthase.
The flow of electrons through ATP synthase
drives an enzyme reaction which converts ADP + Pi to ATP.
ATP synthase is an enzyme embedded in the cristae membrane.
H+create an electrochemical gradient (chemical potential energy).
The H+pass through a channel in the enzyme driving the motor.
The motor spins bringing together ADP and Pi to produce ATP
NADH + H+, FADH2, O2
ATP, H2O, NAD+, FAD