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Biology P4 random notes
- Thread starter zeebujha
- Start date
Your definition made it clearer. If we suppose that ATP should be going in the direction of formation of ADP by hydrolysis, this happens very quickly as it is an immediate source of energy being catalysed by enzyme ATPase. Then, the opposite direction becomes reformation of ATP from ADP. And the reversible reaction of ADP->ATP catlaysed by ATP synthase is also fast. So, the turnover number is highMukeshG93 said:
Anyhow, more final points on Respiration:
Anaerobic respiration occurs when there is a lack of oxygen in the mitochondria and so the electrons from the ETC and the protons (hydrogen ions) will have nowhere to go and will accumulate in the intermembranal space. Due to this, the electrons and protons start binding again to the oxidized NAD and FAD molecules in the mitochondrion and they once again return to their reduced forms. This brings about a problem as the Hydrogens formed at the Krebs cycle and the previous reactions cannot be accepted by any more hydrogen carriers. Hence, the hydrogen carriers have to find another place to dump the protons and electrons. In plants, pyruvate is first decarboxylized to ethanal and then reduced by the hydrogen carriers to ethanol (basic chemistry). In animals, however, pyruvate is directly reduced to lactate. Lactate can be reused for its energy content by further processing in the liver but ethanol cannot, so it is practically a waste of the energy content of pyruvate.
Anaerobic respiration occurs when there is a lack of oxygen in the mitochondria and so the electrons from the ETC and the protons (hydrogen ions) will have nowhere to go and will accumulate in the intermembranal space. Due to this, the electrons and protons start binding again to the oxidized NAD and FAD molecules in the mitochondrion and they once again return to their reduced forms. This brings about a problem as the Hydrogens formed at the Krebs cycle and the previous reactions cannot be accepted by any more hydrogen carriers. Hence, the hydrogen carriers have to find another place to dump the protons and electrons. In plants, pyruvate is first decarboxylized to ethanal and then reduced by the hydrogen carriers to ethanol (basic chemistry). In animals, however, pyruvate is directly reduced to lactate. Lactate can be reused for its energy content by further processing in the liver but ethanol cannot, so it is practically a waste of the energy content of pyruvate.
Straight from the syllabus:
L Energy and respiration
Content
• The need for energy in living organisms
• Respiration as an energy transfer process
• Aerobic respiration
• Anaerobic respiration
• The use of respirometers
Learning Outcomes
Candidates should be able to:
(a) outline the need for energy in living organisms, as illustrated by anabolic reactions, active
transport, movement and the maintenance of body temperature;
(b) describe the structure of ATP as a phosphorylated nucleotide;
(c) describe the universal role of ATP as the energy currency in all living organisms;
(d) explain that the synthesis of ATP is associated with the electron transport chain on the
membranes of the mitochondrion;
(e) outline glycolysis as phosphorylation of glucose and the subsequent splitting of hexose
phosphate (6C) into two triose phosphate molecules, which are then further oxidised with a small
yield of ATP and reduced NAD;
(f) explain that, when oxygen is available, pyruvate is converted into acetyl (2C) coenzyme A, which
then combines with oxaloacetate (4C) to form citrate (6C);
(g) outline the Krebs cycle, explaining that citrate is reconverted to oxaloacetate in a series of small
steps in the matrix of the mitochondrion (no further details are required);
(h) explain that these processes involve decarboxylation and dehydrogenation and describe the role
of NAD;
(i) outline the process of oxidative phosphorylation, including the role of oxygen (no details of the
carriers are required);
(j) explain the production of a small yield of ATP from anaerobic respiration and the formation of
ethanol in yeast and lactate in mammals, including the concept of oxygen debt;
(k) explain the relative energy values of carbohydrate, lipid and protein as respiratory substrates;
(l) define the term respiratory quotient (RQ);
(m) [PA] carry out investigations, using simple respirometers, to measure RQ and the effect of
temperature on respiration rate;
use the knowledge gained in this section in new situations or to solve related problems
Let's use this as reference and define each point as fully as possible.
L Energy and respiration
Content
• The need for energy in living organisms
• Respiration as an energy transfer process
• Aerobic respiration
• Anaerobic respiration
• The use of respirometers
Learning Outcomes
Candidates should be able to:
(a) outline the need for energy in living organisms, as illustrated by anabolic reactions, active
transport, movement and the maintenance of body temperature;
(b) describe the structure of ATP as a phosphorylated nucleotide;
(c) describe the universal role of ATP as the energy currency in all living organisms;
(d) explain that the synthesis of ATP is associated with the electron transport chain on the
membranes of the mitochondrion;
(e) outline glycolysis as phosphorylation of glucose and the subsequent splitting of hexose
phosphate (6C) into two triose phosphate molecules, which are then further oxidised with a small
yield of ATP and reduced NAD;
(f) explain that, when oxygen is available, pyruvate is converted into acetyl (2C) coenzyme A, which
then combines with oxaloacetate (4C) to form citrate (6C);
(g) outline the Krebs cycle, explaining that citrate is reconverted to oxaloacetate in a series of small
steps in the matrix of the mitochondrion (no further details are required);
(h) explain that these processes involve decarboxylation and dehydrogenation and describe the role
of NAD;
(i) outline the process of oxidative phosphorylation, including the role of oxygen (no details of the
carriers are required);
(j) explain the production of a small yield of ATP from anaerobic respiration and the formation of
ethanol in yeast and lactate in mammals, including the concept of oxygen debt;
(k) explain the relative energy values of carbohydrate, lipid and protein as respiratory substrates;
(l) define the term respiratory quotient (RQ);
(m) [PA] carry out investigations, using simple respirometers, to measure RQ and the effect of
temperature on respiration rate;
use the knowledge gained in this section in new situations or to solve related problemsLet's use this as reference and define each point as fully as possible.
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MukeshG93 said:
Oxford(iPhone app)- turnover- the rate at which goods are sold and replaced in a shop
Consistent.
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zeebujha said:yep!NIXORCollege said:
what about the enzyme involved in photolysis?
Sigh. It's some complex. I don't know the name
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MukeshG93 said:
What it really means:
oxygen debt- The physiological state that exists in a normally aerobic animal when insufficient oxygen is available for metabolic requirements (e.g. during a period of strenuous physical activity). To meet the body's increased demand for energy, pyruvate is converted anaerobically (i.e. in the absence of oxygen) to lactic acid, which requires oxygen for its breakdown and accumulates in the tissues. When oxygen is available again lactic acid is oxidized in the liver, thus repaying the debt.
NIXORCollege said:
To sum up:
Oxygen debt simply is the volume of oxygen required to allow the oxidation of all lactate back to to pyruvate by the liver cells.Usually, about 20% of pyruvate so formed is oxidised to CO2 and H2O by the regular aerobic oxidation. The remainder of pyruvate is converted to glucose by gluconeogenesis (which can then be converted to glycogen)
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check out this thread
viewtopic.php?f=26&t=8330
viewtopic.php?f=26&t=8330
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zeebujha said:
Neither are stages of mitosis or meiosis.
Mitosis and Meiosis are NUCLEAR divisions,hence they can be divides into PMAT. Cytokinesis is the division of cytoplasm and Interphase is a stage in the Cell Cycle.
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divided* :O
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zeebujha said:
but it says
The mitotic phase is a relatively short period of the cell cycle. It alternates with the much longer interphase, where the cell prepares itself for cell division. Interphase is therefore not part of mitosis.