RESPIRATION IN HUMANS
UNIT 10 ASSIGNMENT B
Explore the effect of the activity on respiration in humans and factors that can affect respiratory
pathways
INTRODUCTION
Respiration, is a metabolic process the body requires when creating an energy form called ATP
(Adenosine Triphosphate), it is the movement of oxygen into the body through inhalation and the
removal of carbon dioxide through exhalation. In this process ATP is formed from the breakdown of
glucose.
Aerobic Respiration:
Is the first type of energy that is produced from the process of breaking down glucose, it turns fats and
sugars into chemical energy which then can be used for many of the body processes such as
Glycolysis or Protein synthesis.
Glucose (C6H12O6) + Oxygen (6O2) → Carbon dioxide (6CO2) + Water (6H2O) + Energy (ATP)
Anaerobic Respiration:
Is the second type of respiration form, it is also a process that uses the breakdown of glucose;
anaerobic respiration is done when there is an absence of oxygen. A common time this process takes
place is when someone is running.
Plants - Glucose (C6H12O6) → Alcohol 2(C2H5OH) + Carbon dioxide 2 (CO2) + Energy (ATP)
Human - Glucose (C6H12O6) → Carbon dioxide 2 (CO2) + Energy (ATP) + Lactic Acid
RESPIRATORY PATHWAYS
Glycolysis pathway
The transition reaction (oxidative decarboxylation)
Krebs cycle (citric acid cycle)
Oxidative phosphorylation in mitochondria
GLYCOLYSIS
Glycolysis is the initial step of cellular respiration, which occurs in all organisms. In the absence of
oxygen, the cells make small amounts of ATP as glycolysis is followed by fermentation. It occurs in
the cytosol of cell. During this stage, six- carbon glucose is broken down into 2 molecules of three-
carbon pyruvate. The pyruvate can be used without oxygen in the process of fermentation, but no
further ATP is produced during this process.
, 1) A phosphate group is added to glucose in the cell cytoplasm, by the action of enzyme
hexokinase. In this, a phosphate group is transferred from ATP to glucose forming glucose,6-
phosphate.
2) Glucose-6-phosphate is isomerised into fructose,6-phosphate by the enzyme
phosphoglucomutase.
3) The other ATP molecule transfers a phosphate group to fructose 6-phosphate and converts it
into fructose 1,6-bisphosphate by the action of the enzyme phosphofructokinase.
4) The enzyme aldolase converts fructose 1,6-bisphosphate into glyceraldehyde 3-phosphate and
dihydroxyacetone phosphate, which are isomers of each other.
5) Triose-phosphate isomerase converts dihydroxyacetone phosphate into glyceraldehyde 3-
phosphate which is the substrate in the successive step of glycolysis.
6) This step undergoes two reactions:
The enzyme glyceraldehyde 3-phosphate dehydrogenase transfers 1 hydrogen
molecule from glyceraldehyde phosphate to nicotinamide adenine dinucleotide to
form NADH + H+.
Glyceraldehyde 3-phosphate dehydrogenase adds a phosphate to the oxidised
glyceraldehyde phosphate to form 1,3-bisphosphoglycerate.
7) Phosphate is transferred from 1,3-bisphosphoglycerate to ADP to form ATP with the help of
phosphoglycerokinase. Thus, two molecules of phosphoglycerate and ATP are obtained at the
end of this reaction.
8) The phosphate of both the phosphoglycerate molecules is relocated from the third to the
second carbon to yield two molecules of 2-phosphoglycerate by the enzyme
phosphoglyceromutase.
9) The enzyme enolase removes a water molecule from 2-phosphoglycerate to form
phosphoenolpyruvate.
10) A phosphate from phosphoenolpyruvate is transferred to ADP to form pyruvate and ATP by
the action of pyruvate kinase. Two molecules of pyruvate and ATP are obtained as the end
products. [1]
KEY POINTS
The process breaks down glucose into two pyruvate molecules.
The process takes place for animals and plants in the cytoplasm of their cells.
Six different enzymes are involved in the process.
The end products of the reaction include 2 pyruvate, 2 ATP and 2 NADH molecules.
UNIT 10 ASSIGNMENT B
Explore the effect of the activity on respiration in humans and factors that can affect respiratory
pathways
INTRODUCTION
Respiration, is a metabolic process the body requires when creating an energy form called ATP
(Adenosine Triphosphate), it is the movement of oxygen into the body through inhalation and the
removal of carbon dioxide through exhalation. In this process ATP is formed from the breakdown of
glucose.
Aerobic Respiration:
Is the first type of energy that is produced from the process of breaking down glucose, it turns fats and
sugars into chemical energy which then can be used for many of the body processes such as
Glycolysis or Protein synthesis.
Glucose (C6H12O6) + Oxygen (6O2) → Carbon dioxide (6CO2) + Water (6H2O) + Energy (ATP)
Anaerobic Respiration:
Is the second type of respiration form, it is also a process that uses the breakdown of glucose;
anaerobic respiration is done when there is an absence of oxygen. A common time this process takes
place is when someone is running.
Plants - Glucose (C6H12O6) → Alcohol 2(C2H5OH) + Carbon dioxide 2 (CO2) + Energy (ATP)
Human - Glucose (C6H12O6) → Carbon dioxide 2 (CO2) + Energy (ATP) + Lactic Acid
RESPIRATORY PATHWAYS
Glycolysis pathway
The transition reaction (oxidative decarboxylation)
Krebs cycle (citric acid cycle)
Oxidative phosphorylation in mitochondria
GLYCOLYSIS
Glycolysis is the initial step of cellular respiration, which occurs in all organisms. In the absence of
oxygen, the cells make small amounts of ATP as glycolysis is followed by fermentation. It occurs in
the cytosol of cell. During this stage, six- carbon glucose is broken down into 2 molecules of three-
carbon pyruvate. The pyruvate can be used without oxygen in the process of fermentation, but no
further ATP is produced during this process.
, 1) A phosphate group is added to glucose in the cell cytoplasm, by the action of enzyme
hexokinase. In this, a phosphate group is transferred from ATP to glucose forming glucose,6-
phosphate.
2) Glucose-6-phosphate is isomerised into fructose,6-phosphate by the enzyme
phosphoglucomutase.
3) The other ATP molecule transfers a phosphate group to fructose 6-phosphate and converts it
into fructose 1,6-bisphosphate by the action of the enzyme phosphofructokinase.
4) The enzyme aldolase converts fructose 1,6-bisphosphate into glyceraldehyde 3-phosphate and
dihydroxyacetone phosphate, which are isomers of each other.
5) Triose-phosphate isomerase converts dihydroxyacetone phosphate into glyceraldehyde 3-
phosphate which is the substrate in the successive step of glycolysis.
6) This step undergoes two reactions:
The enzyme glyceraldehyde 3-phosphate dehydrogenase transfers 1 hydrogen
molecule from glyceraldehyde phosphate to nicotinamide adenine dinucleotide to
form NADH + H+.
Glyceraldehyde 3-phosphate dehydrogenase adds a phosphate to the oxidised
glyceraldehyde phosphate to form 1,3-bisphosphoglycerate.
7) Phosphate is transferred from 1,3-bisphosphoglycerate to ADP to form ATP with the help of
phosphoglycerokinase. Thus, two molecules of phosphoglycerate and ATP are obtained at the
end of this reaction.
8) The phosphate of both the phosphoglycerate molecules is relocated from the third to the
second carbon to yield two molecules of 2-phosphoglycerate by the enzyme
phosphoglyceromutase.
9) The enzyme enolase removes a water molecule from 2-phosphoglycerate to form
phosphoenolpyruvate.
10) A phosphate from phosphoenolpyruvate is transferred to ADP to form pyruvate and ATP by
the action of pyruvate kinase. Two molecules of pyruvate and ATP are obtained as the end
products. [1]
KEY POINTS
The process breaks down glucose into two pyruvate molecules.
The process takes place for animals and plants in the cytoplasm of their cells.
Six different enzymes are involved in the process.
The end products of the reaction include 2 pyruvate, 2 ATP and 2 NADH molecules.
