Cellular
Respiration
Kayla Damon
,Definitions
• Metabolism: chemical processes in organisms which are controlled by enzymes
• Catabolic: a metabolic process in which complex molecules are broken down into simple ones to rele
energy
• Anabolic: the synthesis of more complex substances from simple molecules
• aerobic respiration: respiration in the presence of oxygen
• Mitochondrion: organelle / site for respiration
• ATP: general energy carrier molecule in cells
• anaerobic respiration: respiration in absence of oxygen
• Fermentation: type of anaerobic respiration in yeast (and other) cells
• alcoholic fermentation: breaking down of glucose in absence of oxygen, to give rise to the production
alcohol in plant cells
• lactic acid fermentation: breaking down of glucose in absence of oxygen to form lactic acid in anima
cells
• lactic acid: acid formed in muscle cells, during anaerobic respiration; leads to muscle exhaustion /
cramping
ADD A FOOTER 2
,Definition of cellular respiration
Cellular respiration is the chemical process where glucose is broken down gradually,
in the presence of oxygen (aerobic respiration) or in the absence of oxygen
(anaerobic respiration), to release energy.
Importance of energy
Energy is used by organisms in various ways. Some of the main ways in which
energy is used include the following:
growth
cell division
movement
transport of substances
active transpor
ADD A FOOTER 3
,Process of cellular respiration
• Aerobic respiration (needs oxygen)
• Aerobic respiration takes place:
in the presence of oxygen;
inside the cytoplasm and mitochondria of cells
ADD A FOOTER 4
,• The requirements for the process are oxygen and glucose and the by-products released are carbon dio
and water as well as ATP energy. This can be shown in the following word equation:
The stages of aerobic respiration
Aerobic respiration takes place in three stages:
1. Glycolysis – takes place in the cytoplasm
2. Krebs Cycle – takes place inside the mitochondrion
3. Oxidative Phosphorylation – takes place inside the mitochondrion
ADD A FOOTER 5
,Glycolysis
takes place outside the mitochondrion, in the cytoplasm of the cell
no oxygen is required during this stage
glucose is broken down into smaller molecules, releasing a small amount of energy that is stored in
energy-rich ATP molecules
• releases high energy hydrogen ions (H+) that are used in the third stage of cellular respiration
(oxidative phosphorylation)
Krebs Cycle
can only take place if oxygen is present
occurs inside of the mitochondrion
releases carbon dioxide and high energy hydrogen ions (H+)
transports hydrogen atoms to the third stage (oxidative phosphorylation) via
hydrogen carrier enzymes
ADD A FOOTER 6
,Oxidative Phosphorylation
takes place inside of the mitochondrion and requires oxygen
passes high energy hydrogen atoms from one hydrogen carrier enzyme to the next, releasing energy
the process
uses released energy to combine a phosphate molecule to an ADP (Adenosine Di-phosphate) molec
to form ATP – called phosphorylation
is represented in the formula: ADP + P ATP
oxygen acts as a final hydrogen acceptor binding with the hydrogen forming water which is released
a waste product of cellular respiration
ADD A FOOTER 7
,Anaerobic respiration (without oxygen)
Anaerobic respiration takes place:
without oxygen being present
it occurs for short periods of time, mainly during physical exercise
occurs differently in plants and animals
produces less ATP than aerobic respiration
Anaerobic respiration in animals
is known as lactic acid fermentation
occurs in muscles during intense exercise
enables glycolysis in the cytoplasm of animal cells
results in the accumulation of lactic acid causing the muscles to become tired
and painful
produces only a small amount of ATP
The lactic acid can be converted back to pyruvic acid when the muscles receive
oxygen
ADD A FOOTER 8
,Anaerobic respiration in plants
is known as alcoholic fermentation
enables glycolysis in the cytoplasm of plant cells
results in the accumulation of pyruvic acid
breaks down pyruvic acid forming ethanol (alcohol) and releasing carbon dioxide in the process
can be summarised as: glucose → ATP + pyruvic acid → ethanol + carbon dioxide
Uses of anaerobic respiration in industry
Yeast and other fungi respire anaerobically and are used to produce alcoholic
beverages such as beer and wine. Yeast cells are also used to cause bread to rise
during the baking process.
The fermentation process is also used to produce cheese. Watch this video on how
cheese is made: https://www.youtube.com/watch?v=TVVpjVk4Gy8
ADD A FOOTER 9
, Comparison between aerobic and anaerobic respiration
ADD A FOOTER 10
Respiration
Kayla Damon
,Definitions
• Metabolism: chemical processes in organisms which are controlled by enzymes
• Catabolic: a metabolic process in which complex molecules are broken down into simple ones to rele
energy
• Anabolic: the synthesis of more complex substances from simple molecules
• aerobic respiration: respiration in the presence of oxygen
• Mitochondrion: organelle / site for respiration
• ATP: general energy carrier molecule in cells
• anaerobic respiration: respiration in absence of oxygen
• Fermentation: type of anaerobic respiration in yeast (and other) cells
• alcoholic fermentation: breaking down of glucose in absence of oxygen, to give rise to the production
alcohol in plant cells
• lactic acid fermentation: breaking down of glucose in absence of oxygen to form lactic acid in anima
cells
• lactic acid: acid formed in muscle cells, during anaerobic respiration; leads to muscle exhaustion /
cramping
ADD A FOOTER 2
,Definition of cellular respiration
Cellular respiration is the chemical process where glucose is broken down gradually,
in the presence of oxygen (aerobic respiration) or in the absence of oxygen
(anaerobic respiration), to release energy.
Importance of energy
Energy is used by organisms in various ways. Some of the main ways in which
energy is used include the following:
growth
cell division
movement
transport of substances
active transpor
ADD A FOOTER 3
,Process of cellular respiration
• Aerobic respiration (needs oxygen)
• Aerobic respiration takes place:
in the presence of oxygen;
inside the cytoplasm and mitochondria of cells
ADD A FOOTER 4
,• The requirements for the process are oxygen and glucose and the by-products released are carbon dio
and water as well as ATP energy. This can be shown in the following word equation:
The stages of aerobic respiration
Aerobic respiration takes place in three stages:
1. Glycolysis – takes place in the cytoplasm
2. Krebs Cycle – takes place inside the mitochondrion
3. Oxidative Phosphorylation – takes place inside the mitochondrion
ADD A FOOTER 5
,Glycolysis
takes place outside the mitochondrion, in the cytoplasm of the cell
no oxygen is required during this stage
glucose is broken down into smaller molecules, releasing a small amount of energy that is stored in
energy-rich ATP molecules
• releases high energy hydrogen ions (H+) that are used in the third stage of cellular respiration
(oxidative phosphorylation)
Krebs Cycle
can only take place if oxygen is present
occurs inside of the mitochondrion
releases carbon dioxide and high energy hydrogen ions (H+)
transports hydrogen atoms to the third stage (oxidative phosphorylation) via
hydrogen carrier enzymes
ADD A FOOTER 6
,Oxidative Phosphorylation
takes place inside of the mitochondrion and requires oxygen
passes high energy hydrogen atoms from one hydrogen carrier enzyme to the next, releasing energy
the process
uses released energy to combine a phosphate molecule to an ADP (Adenosine Di-phosphate) molec
to form ATP – called phosphorylation
is represented in the formula: ADP + P ATP
oxygen acts as a final hydrogen acceptor binding with the hydrogen forming water which is released
a waste product of cellular respiration
ADD A FOOTER 7
,Anaerobic respiration (without oxygen)
Anaerobic respiration takes place:
without oxygen being present
it occurs for short periods of time, mainly during physical exercise
occurs differently in plants and animals
produces less ATP than aerobic respiration
Anaerobic respiration in animals
is known as lactic acid fermentation
occurs in muscles during intense exercise
enables glycolysis in the cytoplasm of animal cells
results in the accumulation of lactic acid causing the muscles to become tired
and painful
produces only a small amount of ATP
The lactic acid can be converted back to pyruvic acid when the muscles receive
oxygen
ADD A FOOTER 8
,Anaerobic respiration in plants
is known as alcoholic fermentation
enables glycolysis in the cytoplasm of plant cells
results in the accumulation of pyruvic acid
breaks down pyruvic acid forming ethanol (alcohol) and releasing carbon dioxide in the process
can be summarised as: glucose → ATP + pyruvic acid → ethanol + carbon dioxide
Uses of anaerobic respiration in industry
Yeast and other fungi respire anaerobically and are used to produce alcoholic
beverages such as beer and wine. Yeast cells are also used to cause bread to rise
during the baking process.
The fermentation process is also used to produce cheese. Watch this video on how
cheese is made: https://www.youtube.com/watch?v=TVVpjVk4Gy8
ADD A FOOTER 9
, Comparison between aerobic and anaerobic respiration
ADD A FOOTER 10
