Assimilation (revised)

Question 1

Define assimilation

Answer 1

• absorbed food substances
• converted to new protoplasm
• used to provide energy

Question 2

How are nutrients transported and utilised

Answer 2

• blood capillaries that supply small intestine unite, form hepatic portal vein
• hepatic portal vein transports sugars and amino acids to liver
• lymphatic capillaries join to form larger lymphatic vessels
• discharge fats into bloodstream

Question 3

Glucose (uses)

Answer 3

• respiration
• produce energy for cellular activities
• excess converted to glycogen, stored in liver and muscles

Question 4

Amino acids (uses)

Answer 4

• synthesis of new proteins, protoplasm
• growth and repair of cells
• cannot be stored, excess deaminated in liver, form urea

Question 5

Fats (uses)

Answer 5

• synthesis of cell membrane

- excess stored in adipose tissues

Question 6

Function of liver

Answer 6

1. Regulation of blood glucose conc
2. Production of bile
3. Deamination of amino acids
4. Storage of iron
5. Detoxification

Question 7

Regulation of blood glucose conc

Answer 7

• islets of langerhans

- insulin and glucagon

Question 8

Production of bile

Answer 8

• temp stored in gall bladder

Question 9

Deamination of amino acids

Answer 9

• liver uses amino acids to synthesize major blood proteins ie. albumins, fibrinogen
• removal of amino grp (NH2), converted to ammonia (toxic to cells) then agn to urea (non-toxic, removed in urine)
• carbon residues of aa frm deaminaton converted to glucose in the liver
• excess glucose converted into glycogen

Question 10

Storage of iron

Answer 10

• worn out rbc destroyed in spleen
• haemoglobin sent to liver to be recycled
• breakdown of haemoglobin produces iron
• iron storedin liver, used in synthesis of new rbc (haemoglobin)
• breakdown of haemoglobin produces bile

Question 11

Detoxification

Answer 11

• process of converting harmful substance to harmless products
• alcohol dehydrogenase (enzyme)
• converts alcohol into acetaldehyde
• acetaldhyde can be broken down during respiration to energy for cell activities

Question 12

Harmful effects of excessive alcohol consumption

Answer 12

1. Symptoms of drunkeness
2. Addiction
3. Liver cirrhosis
4. Stimulates acid secretion in stomach, higher risks of stomach ulcer

Question 13

Liver cirrhosis

Answer 13

• detoxifying high levels of alcohol lead t accumulation of fatty acids
• cause liver to become inflamed / hepatitis
• long term abuse destroys liver tissue calls, replaced with fibrous tissue
• liver function reduced