You are having a really busy day. Late in the afternoon you realize that you forgot to
eat lunch; you haven’t had anything to eat or drink for six hours. Describe the
strategies that your body is using to maintain the supply of energy substrates to your
tissues.
keywords: glucagon liver muscle
Okay so you forgot to eat in six hours, it happens to the best of us. Fortunately enough for us
our body has some pretty cool procedures when it comes to maintaining our body’s supply of
energy especially when it starts to run out.
To start off, our metabolism has two states. The Fed and Fasted state. The two processes are
highlighted in figure 1.1. The FED state happens right after you eat. Your body starts to
anabolically absorb the nutrients and also stores them to use them late. The nutrients include
high glucose, amino acids and fatty acids. Glucose turns into glycogen, amino acids become
synthesised into proteins and fatty acids are turned into triglycerides which become stored as
fat or adipose.
The Fasted state on the other hand happens when there is a long period where food intake
doesn’t happen. This causes us to prompt our body to use the energy reserves in order to
sustain ourselves until the next meal intake. During this time our body has many options to
get access to the energy stores. Glycogen which is in the liver and muscles can go through a
process where gluconeogenesis gets turned into glucose for ATP production. Another way is
triglycerides can become ready with glycerol to be exported to the liver in order for it to be
converted into glucose using the same process. This can be seen in figure 1.2
During the times of starvation ketogenesis as seen in figure 1.3 is a process that becomes a
key process. Particularly when fat breaks down exceeding the processing capacity which
leads to the production of ketones which act as an alternative fuel source specifically for the
brain. However, due to the amount of ketones, they can potentially be a risk for metabolic
acidosis due to how acidic they are. Muscle proteins can also be broken down into amino
acids for gluconeogenesis, but for this the downside is that this process can speed up muscle
loss which can be even worse.
eat lunch; you haven’t had anything to eat or drink for six hours. Describe the
strategies that your body is using to maintain the supply of energy substrates to your
tissues.
keywords: glucagon liver muscle
Okay so you forgot to eat in six hours, it happens to the best of us. Fortunately enough for us
our body has some pretty cool procedures when it comes to maintaining our body’s supply of
energy especially when it starts to run out.
To start off, our metabolism has two states. The Fed and Fasted state. The two processes are
highlighted in figure 1.1. The FED state happens right after you eat. Your body starts to
anabolically absorb the nutrients and also stores them to use them late. The nutrients include
high glucose, amino acids and fatty acids. Glucose turns into glycogen, amino acids become
synthesised into proteins and fatty acids are turned into triglycerides which become stored as
fat or adipose.
The Fasted state on the other hand happens when there is a long period where food intake
doesn’t happen. This causes us to prompt our body to use the energy reserves in order to
sustain ourselves until the next meal intake. During this time our body has many options to
get access to the energy stores. Glycogen which is in the liver and muscles can go through a
process where gluconeogenesis gets turned into glucose for ATP production. Another way is
triglycerides can become ready with glycerol to be exported to the liver in order for it to be
converted into glucose using the same process. This can be seen in figure 1.2
During the times of starvation ketogenesis as seen in figure 1.3 is a process that becomes a
key process. Particularly when fat breaks down exceeding the processing capacity which
leads to the production of ketones which act as an alternative fuel source specifically for the
brain. However, due to the amount of ketones, they can potentially be a risk for metabolic
acidosis due to how acidic they are. Muscle proteins can also be broken down into amino
acids for gluconeogenesis, but for this the downside is that this process can speed up muscle
loss which can be even worse.
