Nutrition & metabolism Flashcards Preview

Anatomy and Physiology > Nutrition & metabolism > Flashcards

Flashcards in Nutrition & metabolism Deck (24):
1

Nutrients

Used for growth repair and maintenance eg. carbohydrates, proteins, fats, minerals and vitamins, water

2

Examples of macronutrients

Water, carbohydrates, proteins and fats

3

Examples of micronutrients

Minerals and vitamins

4

Carbs

Monosaccharides:
- glucose
- galactose
- fructose
Disaccharides:
- sucrose
- maltose
- lactose
Polysaccharides:
- starch
- glycogen
- cellulose
ALL carbs generate glucose - converted to energy
Required daily amount = 230g/day

5

Fibre

Absorbs water into the intestine = softens stool
Provides bulk so speeds up transmit time
Daily requirements = 24g/day

6

Protein

Broken down into amino acids in digestive tract then synthesised into new proteins
20 amino acids eg. glutamine, tyrosine
Daily requirements = 45-60g/day depending on age and sex

7

Lipids

Energy store
Absorption of fat-soluble vitamins
Plasma membranes & myelin
Precursor of steroid and prostaglandins
Daily requirements = 70g/day of which 20g saturated
Lipids are not water soluble so transported in blood as lipoprotein droplets
Low-density lipoproteins = bad as transport cholesterol to tissues
High-density lipoproteins = good as transport cholesterol to liver for elimination

8

What are chylomicrons?

Protein coated lipid droplets
Transport triglycerides and cholesterol from S intestine to liver

9

Vitamins

Fat soluble = A,D,E,K
Water soluble B, C
some synthesised by the body

10

Minerals

calcium, phosphorous, iron, magnesium, folate etc..

11

Nutrition during pregnancy

Increase fibre and protein
Increase calcium, folate, zinc, iodine, iron

12

Anabolism

Small molecules joined together to form complex structures
- uses energy

13

Catabolism

Large molecules broken down into smaller ones
- releases ATP

14

Basal metabolic rate

Energy released requires to support vital organs at rest

15

Carbohydrate metabolism

Anabolism - glucose converted to glycogen/triglycerides for storage
Catabolism - glucose used to form ATP by glycolysis
Total ATP = 38

16

Protein metabolism

Anabolism - amino acids used to form new proteins
Catabolism - amino acids enter Krebs cycle, deaminated by removal of NH2, NH2 becomes NH3 (ammonia) - converted to urea by liver and excreted in urine

17

Lipid metabolism

Anabolism - fatty acids + glycerol = triglyceride, lipogenesis = triglycerides formed from amino acids and glucose
Catabolism - lipolysis, breaking down fats for fuel

18

Metabolic states

Absorptive - up to 4 hours after a meal, mainly anabolic
Postabsorptive - from 4 hours after next to next meal, catabolic

19

Normal blood glucose

3.5-8

20

Glycogenesis

Synthesis of glycogen from glucose

21

Glycogenolysis

Breakdown of glycogen to glucose

22

Gluconeogenesis

Synthesis of glucose from amino acids

23

Blood glucose homeostasis

During absorptive state = blood glucose is high
- insulin secreted from B cells in islets of Langerhans
- this lowers blood glucose levels by increasing entry of glucose into cells, stimulating glycogenesis, inhibiting gluconeogenesis
During post absorptive state - blood glucose is low
- glucagon is secreted from alpha cells in islets of Langerhans
- stimulates glycogenolysis and gluconeogenesis

24

Ketones

When liver breaks down fats and proteins:
- too much acetyl-coA to enter krebs cycle - acetyl-coA converted into ketones
too many ketones = ketoacidosis
Diabetes mellitus = lack of insulin leads to increased breakdown of fats and amino acids = ketoacidosis