Metabolism

Question 1

Define the term catabolism

Answer 1

Large molecules broken down ugh small ones and RELEASE energy (ATP)

Question 2

What is the major source and use of carbohydrates

Answer 2

• 230g/day -
  Sources - mostly plants. Pasta, rice, bread and potatoes
  Uses - generate glucose that is converted to energy, forms structural components of other molecules and provides energy stores

Question 3

What is the major source and use of fibre

Answer 3

• 24g/day -
  Sources - animals or plans. Beans, fruit, nuts, seeds, vegetables
  Uses - absorbs water in the intestines and softens stool. Provides bulk so speeds up transit time

Question 4

What is the major source and use of protein?

Answer 4

• 40-60g/day -
  Sources - red meat, eggs, milk, rice, beans and nuts
  Uses - DNA/RNA, enzymes and reactions, Haemoglobin, bones, hormones, antibodies and keratin

Question 5

What is the major source and use of fats

Answer 5

• 70g/day -
  Sources - animal products, nuts, seeds, oil, egg yolk, cream and shellfish
  Uses - energy sources, absorption of fat-soluble vitamins (A,D,E,K). Plasma membrane and myelin. Precursors of steroids, bile salts, vitamin D and prostaglandins

Question 6

What is the major source and use of vitamins and minerals

Answer 6

• Various/day -
  Sources - meat, veg, milk, eggs, fish and shellfish
  Uses - acts as co-enzymes in metabolism

Question 7

Define basal metabolic rate (BMR)

Answer 7

Energy release required to support vital organs at rest (sleep)

Question 8

Define the term energy balance

Answer 8

The relationship between ‘energy in’ (food) and ‘energy out’ (energy used by the body for daily energy requirements)

Question 9

How are carbohydrates anabolised and catabolised

Answer 9

• ANABOLISM -
  Glucose converted to Glycogen or Triglycerides for storage
• CATABOLISM -
  Glucose is used to form ATO by glycolysis or the TCA (Krebb) cycle.

Question 10

How is protein anabolised and catabolised?

Answer 10

• ANABOLISM -
  Amino acids used to form new proteins
• CATABOLISM -
  Amino acids can enter TCA (Krebb) cycle. They must first lose an amino to become ammonia which is a toxic substance converted to urea by the liver and excreted in urine.

Question 11

How are fats anabolised and catabolised?

Answer 11

• ANABOLISM -
  Fatty acids and glycerol = triglycerides
  Lipogenesis = triglycerides formed from amino acids and glucose
• CATABOLISM -
  Lipolysis - breaking down fat for fuel.

Question 12

Define the term glycolysis

Answer 12

Glucose is continuously entering the cell and is quickly metabolised for energy. Once inside it undergoes glycolysis where is is split into 2 pyruvic acid and 2 ATP

Question 13

Define the term glycogenesis

Answer 13

Synthesis of glycogen FROM glucose

Question 14

Define the term glycogenolysis

Answer 14

Breakdown of glycogen INTO glucose

Question 15

Define gluconeogenesis

Answer 15

Synthesis of glucose FROM amino acids

Question 16

Define the term anabolism

Answer 16

Small molecules joined together to form complex structures USING energy (ATP)

Question 17

What are glucocorticoids?

Answer 17

They are substances released by the adrenal cortex (cortisol) and they stimulate gluconeogenesis

Question 18

An example of a micronutrient is:

Answer 18

Minerals

Question 19

Hydrochloric acid is produced by:

Answer 19

Parietal cells

Question 20

Which class of lipoproteins removes the cholesterol from the blood and returns it to the liver for elimination?

Answer 20

HDL’s

Question 21

Which hormone stimulates gastric motility and secretion?

Answer 21

Gastrin

Question 22

The layers of the digestive tract in the correct order from interior outward are:

Answer 22

Mucosa ~ submucosa ~ muscularis externa ~ serosa