Unit 10: Biological molecules and metabolic pathways
Unit 10B: Explore the effect of activity on respiration in humans and factors
that can affect respiratory pathways
Vocational Scenario:
I am working as a research assistant in the School of Sport, Exercise and Health Sciences at Aston
University. My supervisor has asked me to produce a portfolio of work for the university’s open day.
This will cover respiratory pathways, how activity and various factors affect respiration and
respiratory pathway in humans. I will need to include evidence of an investigation I have carried out
into the effect of activity on respiration in humans.
Introduction:
Respiration is a vital process that occurs in many living organisms such as humans, plants and
animals. We will be exploring respiration in humans. Respiration occurs mainly in the lungs, there
are two parts to respiration, inspiration and expiration. Inspiration is when air is taken into the body
and from the air taken into the lung's oxygen is taken into the lungs and expiration is when carbon
dioxide is breathed out of the lungs and back into the air and the process just repeats over and over
again. In humans' respiration occurs in four different stages: Glycolysis, Link reaction, Krebs cycle and
Oxidative phosphorylation. A way that respiration is represented simply is in a formula:
Glucose + Oxygen --------> Carbon dioxide + Water (+ ATP)
In the four stages of respiration previously mentioned there are some differences with a certain
element needed. The element that is different and may not need to be used is oxygen.
Aerobic respiration:
If something is aerobic, it means that oxygen is needed in the reaction. In respiration three stages
require oxygen and those three stages are link reaction, Krebs cycle and oxidative phosphorylation.
In aerobic respiration oxygen is used with glucose and produces carbon dioxide, water and energy or
more specifically ATP.
Anaerobic respiration:
If something is anaerobic, it means that oxygen is not needed in the reaction. Anaerobic respiration
takes place in only one phase of respiration, and it takes place in glycolysis. In glycolysis oxygen is
not required and the reaction can go on without any oxygen as normal. Going back to the formula of
respiration which is: Glucose + Oxygen --------> Carbon dioxide + Water (+ ATP). We can see that
glucose reacts with oxygen, however during anaerobic respiration there is no oxygen to react with
glucose so instead this leads to another reaction and this reaction is the production of lactic acid.
There are 2 steps to anaerobic respiration: Glycolysis and lactate fermentation.
Production of lactic acid in anaerobic respiration + Lactate fermentation:
, Lactic acid is produced due to the lack of oxygen in respiration in relation to no oxygen. It is made
from glucose and is synthesised in the muscle tissue. An equation to represent the production of
lactic acid is Glucose-------> Lactic Acid. After the process of glycolysis, the subsequent stage of
anaerobic respiration is lactate fermentation is done next.
Lactate fermentation:
1. NADH made in glycolysis has oxygen added and becomes NAD+
2. Pyruvate instead of NAD as usual takes the hydrogen from NADH
3. This leads to the production of pyruvate and the production of lactate
4. NAD adds oxygen and this leads to it receiving hydrogen from glucose
5. Glycolysis can thus proceed to produce 2 ATP molecules
The excess lactate produced is transported to the liver in the blood for glucose until oxygen
accessible. When oxygen becomes more abundant lactate is changed to pyruvate and will be bused
in the Krebs Cyle to facilitate ATP production.
Ethanol in yeast:
As opposed to lactate fermentation, ethanol is produced during alcohol fermentation. The process of
alcohol fermentation is when yeast cells turn glucose into ethanol and carbon dioxide when there is
no oxygen. This process is normally used when making beer and bread.
ATP:
Adenosine triosephosphate also known as ATP is one of the main products produced in respiration,
it is used as the main source of energy in pretty much every reaction in living organisms. ATP is
composed of adenosine a nucleotide that is produced from adenine, a ribose molecule which is a 5-
carbon sugar compound and 3 phosphate groups. The main purpose of ATP is to act as an energy
source for living organisms and to produce and release that energy as fast as possible. It’s
importance in respiration is to offer quick energy release and for it to do that it must produce said
energy as quickly as possible as the respiration pathway in humans needs to be as fast as possible
due to the cells in the body needing energy when performing strenuous and vigorous tasks.
Glycolysis:
Glycolysis is the first stage of respiration and is the only stage of respiration that is anaerobic which
means that it does not need oxygen. It usually involves the breakdown of a monosaccharide mainly
glucose into pyruvate. The process takes place in the cytoplasm of the cell and there are four parts
of glycolysis:
Step 1: Phosphorylation
When glucose enters the cytoplasm water is added to an ATP molecule this is a hydrolysis reaction
as water is used to split a substance into smaller molecules. A phosphate group is produced and
Unit 10B: Explore the effect of activity on respiration in humans and factors
that can affect respiratory pathways
Vocational Scenario:
I am working as a research assistant in the School of Sport, Exercise and Health Sciences at Aston
University. My supervisor has asked me to produce a portfolio of work for the university’s open day.
This will cover respiratory pathways, how activity and various factors affect respiration and
respiratory pathway in humans. I will need to include evidence of an investigation I have carried out
into the effect of activity on respiration in humans.
Introduction:
Respiration is a vital process that occurs in many living organisms such as humans, plants and
animals. We will be exploring respiration in humans. Respiration occurs mainly in the lungs, there
are two parts to respiration, inspiration and expiration. Inspiration is when air is taken into the body
and from the air taken into the lung's oxygen is taken into the lungs and expiration is when carbon
dioxide is breathed out of the lungs and back into the air and the process just repeats over and over
again. In humans' respiration occurs in four different stages: Glycolysis, Link reaction, Krebs cycle and
Oxidative phosphorylation. A way that respiration is represented simply is in a formula:
Glucose + Oxygen --------> Carbon dioxide + Water (+ ATP)
In the four stages of respiration previously mentioned there are some differences with a certain
element needed. The element that is different and may not need to be used is oxygen.
Aerobic respiration:
If something is aerobic, it means that oxygen is needed in the reaction. In respiration three stages
require oxygen and those three stages are link reaction, Krebs cycle and oxidative phosphorylation.
In aerobic respiration oxygen is used with glucose and produces carbon dioxide, water and energy or
more specifically ATP.
Anaerobic respiration:
If something is anaerobic, it means that oxygen is not needed in the reaction. Anaerobic respiration
takes place in only one phase of respiration, and it takes place in glycolysis. In glycolysis oxygen is
not required and the reaction can go on without any oxygen as normal. Going back to the formula of
respiration which is: Glucose + Oxygen --------> Carbon dioxide + Water (+ ATP). We can see that
glucose reacts with oxygen, however during anaerobic respiration there is no oxygen to react with
glucose so instead this leads to another reaction and this reaction is the production of lactic acid.
There are 2 steps to anaerobic respiration: Glycolysis and lactate fermentation.
Production of lactic acid in anaerobic respiration + Lactate fermentation:
, Lactic acid is produced due to the lack of oxygen in respiration in relation to no oxygen. It is made
from glucose and is synthesised in the muscle tissue. An equation to represent the production of
lactic acid is Glucose-------> Lactic Acid. After the process of glycolysis, the subsequent stage of
anaerobic respiration is lactate fermentation is done next.
Lactate fermentation:
1. NADH made in glycolysis has oxygen added and becomes NAD+
2. Pyruvate instead of NAD as usual takes the hydrogen from NADH
3. This leads to the production of pyruvate and the production of lactate
4. NAD adds oxygen and this leads to it receiving hydrogen from glucose
5. Glycolysis can thus proceed to produce 2 ATP molecules
The excess lactate produced is transported to the liver in the blood for glucose until oxygen
accessible. When oxygen becomes more abundant lactate is changed to pyruvate and will be bused
in the Krebs Cyle to facilitate ATP production.
Ethanol in yeast:
As opposed to lactate fermentation, ethanol is produced during alcohol fermentation. The process of
alcohol fermentation is when yeast cells turn glucose into ethanol and carbon dioxide when there is
no oxygen. This process is normally used when making beer and bread.
ATP:
Adenosine triosephosphate also known as ATP is one of the main products produced in respiration,
it is used as the main source of energy in pretty much every reaction in living organisms. ATP is
composed of adenosine a nucleotide that is produced from adenine, a ribose molecule which is a 5-
carbon sugar compound and 3 phosphate groups. The main purpose of ATP is to act as an energy
source for living organisms and to produce and release that energy as fast as possible. It’s
importance in respiration is to offer quick energy release and for it to do that it must produce said
energy as quickly as possible as the respiration pathway in humans needs to be as fast as possible
due to the cells in the body needing energy when performing strenuous and vigorous tasks.
Glycolysis:
Glycolysis is the first stage of respiration and is the only stage of respiration that is anaerobic which
means that it does not need oxygen. It usually involves the breakdown of a monosaccharide mainly
glucose into pyruvate. The process takes place in the cytoplasm of the cell and there are four parts
of glycolysis:
Step 1: Phosphorylation
When glucose enters the cytoplasm water is added to an ATP molecule this is a hydrolysis reaction
as water is used to split a substance into smaller molecules. A phosphate group is produced and
