Chapter 12 energy and respiration Flashcards
To learn about aerobic and anaerobic respiration
Define respiration
The enzymatic release of energy from organic compounds in living things
Define anabolic reaction
A chemical reaction in which smaller molecules are built up into larger ones
Why ATP makes the perfect energy currency?
-the hydrolysis of ATP can be done quickly and easily, in whichever part of the cell the energy is required
-the hydrolysis of one molecule of ATP can release a useful quantity of energy, enough to fuel an energy requiring process in a cell and not so much is wasted
-ATP is a relatively stable molecule in a range of pH that normally occurs in the cell, it doesn’t break down unless the catalyst ATPase enzyme is present.
How much KJ/mol is released from the removal of phosphate from ATP,ADP,AMP and how and why is it removed
-ATP: 30.5KJ/mol
-ADP: 30.5KJ/mol
-AMP: 14.2KJ/mol
It is removed by hydrolysis to release energy
What are the two main ways in which ATP is made by ADP and a phosphate group
-substrate linked phosphorylation
-chemiosmosis
Define substrate linked phosphorylation
The transfer of phosphate from a substrate molecule directly to a ADP to produce ATP, using energy provided by other chemical reaction
Define chemiosmosis
The synthesis of ATP using energy released by the movement of hydrogen ions down their concentration gradient, across a membrane in a mitochondria and chloroplast
Define glycolysis
Lysis of glucose, first stage in aerobic respiration
Define phosphorylation
The addition of phosphate group to a molecule
What is NAD? Full form?
-hydrogen carrier
-Nicotinamide adenine dinucleotide
What is oxidation
Addition of oxygen, removal of hydrogen or electron from a substance
What is reduction
Removal of oxygen, addition of hydrogen or electron to a substance
What is the four stages of aerobic respiration and where does it take place?
1) glycolysis takes place in the cytoplasm of the cell
2) the link reaction takes place in the matrix of mitochondria
3) the Krebs cycle takes place in the matrix of the mitochondria
4) oxidative phosphorylation takes place in the inner mitochondrial membrane
Describe glycolysis
(check textbook)
Describe link reaction
(check textbook)
Describe Krebs cycle
(check textbook)
Describe oxidative phosphorylation
(check textbook)
What is decarboxylation
Removal of CO2 from a substance
What is dehydrogenation
Removal of hydrogen from substance
Define CoA
Molecule that supplies acetyl groups required for the link reaction
Define acetyl CoA
Molecule made up of CoA and 2C acetyl group, important for the link reaction
Define link reaction
Decarboxylation and dehydrogenation of pyruvate takes place, resulting in the formation of acetyl CoA, linking glycolysis and Krebs cycle
Define Krebs cycle
A cycle of reactions in aerobic respiration in the matrix of mitochondria in which hydrogen passed to hydrogen carriers for subsequent ATP synthesis and some ATP is synthesized directly also known as the Citric acid cycle
Define oxidative phosphorylation
The synthesis of ATP from ADP and Pi using energy from oxidation reaction in aerobic respiration
What is electron transport chain(ETC)
A chain of adjacently arranged carrier molecules in the inner mitochondrial membrane, along which electrons pass in redox reaction
What is redox reaction
A chemical reaction in which one substance is reduced and another is oxidised
What is ATP synthase
The enzyme that catalyzes the phosphorylation of ADP to produce ATP
What happens if there is no or very little oxygen inside mitochondria
-ETC stops working and no further ATP is formed by oxidative phosphorylation
-no free carrier protein in the chain to accept hydrogen from reduced NAD and FAD, so these remain reduced
-krebs cycle stops running because there is no oxidised NAD and FAD to enable the dehydrogenation steps to take place
Describe how the structure of mitochondria is related to it’s function
-It is a rod shaped or filamentous (0.5-1.0micrometre).
-The no. of mitochondria in a cell depends on its activity.
-Site of aerobic respiration
-It has a double membrane, outer and inner membrane. Outer membrane is permeable to all small molecules, this allows the movement of substance required and produced by the link reaction, Krebs cycle and oxidative phosphorylation such as oxygen, carbon dioxide, ATP, ADP and Pi. The inner membrane is impermeable to H+.
-the inner membrane is folded to form cristae which increases the surface area.
-On cristae are ATP synthase present where chemiosmosis takes place.
-Between two membrane is the inter membrane space with high H+ concentration and a proton gradient is maintained.
-Matrix fills mitochondria and is a site for link reaction and Krebs cycle.
-Mitochondria has it’s own looped DNA and 70s ribosomes for the synthesis of enzymes needed for link reaction and Krebs cycle.
Define anaerobic respiration
Without oxygen
What is ethanol fermentation
Anaerobic respiration in which pyruvate is converted to ethanol
What is lactate fermentation
Anaerobic respiration in which pyruvate is converted to lactate
What is the two type of fermentation taking place in anaerobic respiration and where?
-ethanolic fermentation takes place in yeast
-lactate fermentation takes place in muscle
What is the similarities of both lactate and ethanol fermentation
-in both fermentation, hydrogen is combined with pyruvate to give the end product
-both are formed by glycolysis
-both process results in oxidised NAD to be used again in glycosis.
-only one product formed at the end to both fermentation
-catalyst is needed for formation of end product
What is the difference in both lactate and ethanol fermentation
Lactate fermentation
-reversible reaction
-one step process
-catalyst is lactate dehydrogenase
-end product is lactate
-decarboxylation doesn’t take place
Ethanol fermentation
-not a reversible reaction
-two step process
-catalyst is alcohol dehydrogenase
-end product is ethanol
-decarboxylation takes place
What is aerenchyma
-Plant tissue containing air space (in roots&stems)
-parenchyma + air= aerenchyma
What is the adaptation of a rice plant?
-rice paddy grows upward faster, to keep its leaves and flower spikes above the water level, so that oxygen and carbon can be exchanged through stomata of the leaves
-stems and roots contain aerenchyma so that gases can diffuse to parts like roots which are underground enabling to respire aerobically
-cell in roots undergo anaerobic respiration that lead to ethanol build up in tissues. These cell are tolerant to high ethanol concentration, which is broken down by ethanol dehydrogenase. This allows the plant to grow actively even when oxygen is scarce, using ATP produced by ethanol fermentation.
RQ formula
-RQ= volume of carbon dioxide given out in unit time/ volume of oxygen taken in unit time
-RQ= moles or molecules of Carbon dioxide given out/ moles or molecules of oxygen taken in
What is the energy density of carbohydrate, lipid and protein
Carbohydrate: 15.8kJ/g
Lipid: 39.4kJ/g
Protein: 17.0kJ/g
What is the respiratory quotient (RQ) of carbohydrate, lipid and protein
Carbohydrate: 1.0
Lipid: 0.7
Protein: 0.9
What is redox indicators
A substance that changed colour when it is oxidised or reduced
What are the two redox indicators and what is the colour change
-DCPIP
-Methylene blue
Blue to colourless when reduced
Describe the structure and role of ATP
-It is a nucleotide
-adenine+ribose+3 phosphate
-small packets of energy
-water soluble so can move around the cell
-protein synthesis
-used by the cell as immediate energy donor
What is the role of ATP in active transport and anabolic reaction?
ATP provides energy
Active transport
-binds to ion
-movement against concentration gradient
-protein changes shape
-carrier transport protein
Anabolic reaction
-synthesis of complex substance from simpler ones
-glycosidic bond
-ester bond
-polypeptide/protein from amino acid
