Discuss the functions of liver in assimilation of digested food: (i) metabolisms of digested food (carbohydrates and proteins), (ii) storage of nutrients, (iii) detoxification

Assimilation

9.4

Assimilation

The Role of The Circulatory System

The human circulatory system consists of the blood circulation system and the lymphatic system to help transport nutrients to be assimilated.
In the assimilation process that occurs in cells, nutrients are used to form complex compounds or structures of components.
The blood capillaries in the small intestine combine to form the hepatic portal vein that transports blood to the liver.
Lacteals combine to form bigger lymph vessels in the lymphatic system.
Then, the contents of the lymph vessels enter the thoracic duct that flows into the left subclavian vein.
This lipid is then transported by blood throughout the body.

Functions of Liver in The Assimilation of Digested Food

The liver is the regulator that controls the quantity of nutrients that enter the blood circulatory system.
The liver carries out the following functions:

Metabolism of Digested Food

Glucose is used for cellular respiration.
Amino acids are used for synthesising plasma proteins and enzymes.
Through the deamination process, excess amino acids are turned into urea to be excreted through the urine.

Detoxification

Liver cells expel toxic substances from the blood.
Toxic substances are expelled through the urine.

Storage of Nutrients

Excess glucose is converted to glycogen to be stored.

Assimilation Process in The Liver

Amino Acids

The liver synthesises plasma protein and enzymes from amino acids.
Excess amino acids cannot be stored in the body and are broken down through the deamination process to form urea which is then expelled.
When the glucose supply is insufficient, the liver converts amino acids into glucose.

Glucose

Glucose in the liver is used for cellular respiration when required by the body and the excess is converted to glycogen and stored in the liver.
When the glucose level in the blood decreases and the body needs energy, glycogen is converted to glucose.
When the glycogen supply reaches a maximum level, the excess glucose is converted to fats.

Assimilation Process in Cells

Amino Acids

Amino acids are used to synthesise new protoplasm and also repair damaged tissues.
Amino acids are used to synthesise hormones and enzymes.

Glucose

Glucose is oxidised through cellular respiration to release energy, water and carbon dioxide.
Excess glucose is kept as glycogen in muscles.
Energy is used for cell processes such as protein synthesis.

Lipids

Lipids such as phospholipid and cholesterol are the primary components that build the plasma membrane.
Excess fats are kept in adipose tissues found underneath the skin as stored energy.
Fat is oxidised to release energy when there is insufficient glucose.

Assimilation

9.4

Assimilation

The Role of The Circulatory System

The human circulatory system consists of the blood circulation system and the lymphatic system to help transport nutrients to be assimilated.
In the assimilation process that occurs in cells, nutrients are used to form complex compounds or structures of components.
The blood capillaries in the small intestine combine to form the hepatic portal vein that transports blood to the liver.
Lacteals combine to form bigger lymph vessels in the lymphatic system.
Then, the contents of the lymph vessels enter the thoracic duct that flows into the left subclavian vein.
This lipid is then transported by blood throughout the body.

Functions of Liver in The Assimilation of Digested Food

The liver is the regulator that controls the quantity of nutrients that enter the blood circulatory system.
The liver carries out the following functions:

Metabolism of Digested Food

Glucose is used for cellular respiration.
Amino acids are used for synthesising plasma proteins and enzymes.
Through the deamination process, excess amino acids are turned into urea to be excreted through the urine.

Detoxification

Liver cells expel toxic substances from the blood.
Toxic substances are expelled through the urine.

Storage of Nutrients

Excess glucose is converted to glycogen to be stored.

Assimilation Process in The Liver

Amino Acids

The liver synthesises plasma protein and enzymes from amino acids.
Excess amino acids cannot be stored in the body and are broken down through the deamination process to form urea which is then expelled.
When the glucose supply is insufficient, the liver converts amino acids into glucose.

Glucose

Glucose in the liver is used for cellular respiration when required by the body and the excess is converted to glycogen and stored in the liver.
When the glucose level in the blood decreases and the body needs energy, glycogen is converted to glucose.
When the glycogen supply reaches a maximum level, the excess glucose is converted to fats.

Assimilation Process in Cells

Amino Acids

Amino acids are used to synthesise new protoplasm and also repair damaged tissues.
Amino acids are used to synthesise hormones and enzymes.

Glucose

Glucose is oxidised through cellular respiration to release energy, water and carbon dioxide.
Excess glucose is kept as glycogen in muscles.
Energy is used for cell processes such as protein synthesis.

Lipids

Lipids such as phospholipid and cholesterol are the primary components that build the plasma membrane.
Excess fats are kept in adipose tissues found underneath the skin as stored energy.
Fat is oxidised to release energy when there is insufficient glucose.

Chapter : Nutrition and Digestive System of Humans

Topic : Discuss the functions of liver in assimilation of digested food: (i) metabolisms of digested food (carbohydrates and proteins), (ii) storage of nutrients, (iii) detoxification

Form 4 Biology

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