Metabolism

Question 0

Monosaccharides

Answer 0

Glucose
Galactose
Fructose

Question 1

Carbohydrates

Answer 1

Monosaccharides
Disaccharides
Polysaccharides
Generate glucose
Convert to energy (neurons and RBCs depend on glucose)
Form structural components of other molecules (glycoproteins )
Provide energy stores (glycogen, excess is stored as fat)
230 g/day

Question 2

Disaccharides

Answer 2

Sucrose - glucose and fructose
Lactose - glucose and galactose
Maltose - glucose and glucose

Question 3

Polysaccharides

Answer 3

Starch
Glycogen (found in small amounts in cooked meats)
Cellulose (not digested in humans, but important source of fibre)

Question 4

Proteins, what they make?

Answer 4

Skeletal muscles
Enzymes
Hormones
Cell membrane receptors
Collagen
Haemoglobin

Question 5

Proteins

Answer 5

20 amino acids
8 can’t be made by the body, so must be ingested:
Leucine, Phenylalanine, Glutamine, Lysine, Tyrosine, Methionine
GDA 40-60 g/day

Question 6

Lipids

Answer 6

Male 15%, female 25%
Twice as much energy as sugars and proteins
Absorption of fat soluble vitamins (K & D)
Plasma membranes and myeline
Precursor of steroids, bile salts, vitamin D, prostaglandins

Question 7

Lipid transport

Answer 7

Transported in blood as lipoprotein droplets
Core is made of cholesterol and triglycerides
Outer coating is made of proteins and phospholipids
- Chylomicrones (protein coated lipid droplets)
- VLDL ( very low density lipoproteins)
- LDLs (less protein, more fat)
Density refers to protein/fat ratio
- HDLs (more protein, less fat)

Question 8

Vitamins

Answer 8

Act as co-enzymes in metabolism
K and D are synthesised by the body
Fat soluble - A, D, E, K
Water soluble - B, C

Question 9

Minerals

Answer 9

Many electrolytes
Recommended Na intake 6g/day
Diet contains 4.5g/day
Only need 2 g/day

Question 10

Metabolism

Answer 10

Anabolism - building, uses energy

Catabolism - breaking, releases energy ATP

Question 11

1 kcal

Answer 11

Amount of heat required to heat 1L of water by 1degree C

1 kcal= 4.184 KJ

Question 12

Metabolic rate

Answer 12

Rate of energy released from cell, thyroxine is involved

Question 13

Basal Metabolic Rate (BMR)

Answer 13

Energy release required to support vital organs at rest (12 hours of fasting in warm environment)
2000 kcal women
2400 kcal men

Question 14

Chylomicrones

Answer 14

Transport triglycerides and cholesterol from small intestine to liver (and adipocytes) via lymphatic vessels.

Question 15

Carbohydrates Anabolism

Answer 15

Glucose converted to glycogen or triglycerides for storage

Question 16

Carbohydrate Catabolism

Answer 16

Glucose is used to form ATP by glycolysis or TCA cycle

Question 17

Glycolysis

Answer 17

Anabolic reaction (no O2 )
Glucose - 2 ATP + 2 pyruvic acid

Question 18

Fate of pyruvate

Answer 18

In the presence of O2 pyruvic acid is converted to lactic acid.
With O2 pyruvic acid passes into mitochondrion to enter the TCA cycle and electron transport chain. This produces 36 ATP

Question 19

Protein Metabolism

Answer 19

Anabolism
- amino acids are used to form new proteins
Catabolism
- amino acids can enter TCA cycle
- NH2 is removed, it becomes NH3 (ammonia), then to urea by the liver, then excreted in the urine.

Question 20

Lipid Metabolism

Answer 20

Anabolism
- fatty acids and glycerol convert to triglycerides 
- lipogenesis: triglycerides formed from from amino acids and glucose
Catabolism
- lipolysis
- breaking down fat for fuel
   Glycerol - glycolysis
   Fatty acids - Acetyl Co A - TCA cycle

Question 21

Metabolic States

Answer 21

Absorptive
- up to 4 hours after meal
- mainly anabolic
Post absorptive
- from 4 hours after meal
- no absorption
- mainly catabolic

Question 22

Normal blood glucose

Answer 22

3.5 - 8.0 mmol/L

Fasting 3.5 - 5.5 mmol/L

Question 23

Glycogenesis

Answer 23

Synthesis of glycogen from glucose

Question 24

Glycogenolysis

Answer 24

Breakdown of glycogen into glucose

Question 25

Gluconeogenesis

Answer 25

Synthesis of glucose from amino acids

Question 26

During Absorptive state

Answer 26

Blood glucose is high | Insulin is secreted by beta cells of pancreas

Question 27

Insulin

Answer 27

``` Beta cells of pancreas Lowers blood glucose by - increasing entry of glucose into cells ( increasing carriers for facilitated diffusion) - stimulating glycogenesis - stimulating protein and fat synthesis - inhibiting gluconeogenesis ```

Question 28

During post absorptive state

Answer 28

``` Prevent blood glucose falling GLUCAGON - secreted by alfa cells in pancreas - stimulates glycogenolysis, gluconeogenesis & lipolysis ADRENALINE - stimulates glycogenolysis and lipolysis (injury, fear, anger, stress) GLUCOCORTICOID ( cortisone , cortisole) - stimulate gluconeogenesis ```

Question 29

Ketones

Answer 29

When the liver breaks down fats and proteins - too much Acetyl-Co A to enter TCA cycle - Acetyl-Co A is converted to ketone bodies Some cells use ketone bodies for energy (heart and kidneys) Too many ketone bodies leads to ketoacidosis

Question 30

Diabetes mellitus

Answer 30

Lack of insulin leads to increased breakdown of fats and amino acids and can result in ketoacidosis

Question 31

How does prosteroegen influence digestion ?

Answer 31

It causes constipation in pregnancy

Question 32

Glucagon

Answer 32

A carbohydrate stored in the liver

Question 33

Glutamine

Answer 33

Amino acid

Question 34

Methionine

Answer 34

Essential amino acid - can't be synthesised by the body | Antidote to paracetamol

Question 35

Leucine

Answer 35

One of 8 essential amino acids

Question 36

Phenylalanine

Answer 36

One of 8 essential amino acids

Question 37

Lysine

Answer 37

One of 8 essential amino acids

Question 38

Tyrosine

Answer 38

Amino acid

Question 39

Glucocorticoid

Answer 39

Promotes glycogen disposition and has anti inflammatory effects

Question 40

Glucagon

Answer 40

Elevates blood glucose level

Question 41

Insuline

Answer 41

Reduces blood glucose levels and promotes protein synthesis

Question 42

Gluconeogenesis

Answer 42

The formation of glucose from non carbohydrates

Question 43

Glycogenolysis

Answer 43

The breakdown of glycogen to glucose

Question 44

Glycolysis

Answer 44

The process by which the cell breaks down to produce ATP

Question 45

Ketoacidosis

Answer 45

Lack of insulin leads to increased breakdown of fats and amino acids and can result in ketoacidosis

Question 46

Ketones

Answer 46

When liver breaks down fats and proteins, Acetyl-Co A enters TCA cycle and is converted to ketone bodies Heart and kidneys use ketones for energy