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Flashcards in Metabolism Deck (86):
0

Nutrients are provided by what?

The foods we eat

1

What is metabolism?

What we do with the nutrients once they are delivered to the cell

2

Provide 6 examples of nutrients used for growth repair and maintenance

Carbohydrates, proteins, fats, minerals, water, vitamins

3

Why must essential nutrients be included in the diet?

Because they cannot be synthesised by the body

4

Glucose, fructose and galactose are which types of carbohydrate?

Monosaccharides

5

Name 3 disaccharides

Sucrose, lactose, maltose

6

Name 3 polysaccharides

Starch, lycogen, cellulose

7

All carbohydrates generate what?

Glucose

8

What are the 3 uses of carbohydrates

Converted to energy (RBCs and neurons depend on glucose)
Form structural components of other molecules eg glycoproteins
Provide energy stores - glycogen, excess converted to fat

9

What is the approx GDA of carbohydrates?

230g day

10

What are the effects of fibre on digestion?

Absorbs water into the intestines and softens stools, provides bulk so speeds up the transit time

11

What is the daily requirement of fibre?

24g day

12

What does excess fibre intake interfere with?

Mineral absorption eg calcium, iron

13

What percentage of body mass is constituted by proteins?

12-15%

14

What are proteins broken down into and where does this take place in the body?

Amino acids in the digestive tract

15

How many amino acids are there?

20

16

How many amino acids are essential?

8

17

What are the GDA requirements of protein?

45-60g day

18

What are the 4 uses of lipids?

Energy storage
Absorption of fat soluble vitamins
Plasma membranes and myelin
Precursor of steroids, bile salts, vitamin D and prostaglandins

19

What is the GDA of fats and what portion of this should be saturates?

70g
20g saturated

20

Are lipids water soluble?

No

21

How are lipids transported?

•Transported in the blood as lipoprotein droplets
–core of cholesterol & triglycerides
–outer coating of proteins and phospholipids

22

Anabolism is?

Synthesis of larger molecules from smaller ones

23

Catabolism is?

Breaking down of larger molecules into smaller ones

24

Give an example of a carbohydrate?

Pasta, potatoes, rice

25

What does the body use carbohydrates for?

Generate glucose
Convert to energy
Form structural components of molecules eg glycoproteins
Provide energy stores eg glycogen

26

What are the major sources of fibre?

Fruit skin, brown bread

27

What are the functions of fibre?

Absorbs water into the intestines and softens stools
Provides bulk to speed up the transit time

28

What does excess fibre interfere with?

Mineral absorption - calcium, iron etc

29

What are the sources of complete proteins? How many of the amino acids do they contain?

All amino acids - Eggs, meat, milk

30

What are the sources of incomplete proteins and how many amino acids do they provide?

Lack one or more essential amino acids, rice, beans, pulses

31

What are the functions of proteins?

Broken down into amino acids in the digestive tract, synthesis of new proteins. Transamination in liver

32

What are the functions of lipids?

Energy storage
Absorption of fat soluble vitamins
Plasma membranes and myelin
Precursor of steroids, bile salts, vit D and prostaglandins

33

Sources of lipids?

Butter, cream, cheese, eggs

34

What do vitamins do?

Act as co enzymes in metabolic activities and carry out many other functions

35

Where can you obtain vitamins?

Meat and vegetables

36

Name 4 fat soluble vitamins.

A
D
E
K

37

Name 2 water soluble vitamins

B and C

38

What are the sources of minerals
?

Vegetables, milk, eggs, meat, fish and shell fish

39

Name some minerals

Calcium, phosphorus, iron, magnesium, manganese, chlorine, folate and other electrolytes

40

What is the recommended sodium intake, required amount and average intake amount?

Red - 6g/day
Required - 2g
Average - 4.5g

41

1kcal = ? KJ

4.18

42

1kcal = ?

Amount of heat required to heat 1litre water by 1 degrees

43

Metabolic rate = ?

Rate of energy released from cells

44

Basal metabolic rate =

Energy released required to support vital organs at rest

45

Describe carbohydrate metabolism during anabolism

Glucose is converted to glycogen or triglycerides for storage

46

Describe carbohydrate metabolism during catabolism?

Glucose is used to form ATP by glycolysis or the TCA cycle

47

Glucose

Fuel molecule required for energy

48

Glycogen

Stored form of glucose

49

Glucagon

Hormone involved in breaking glycogen to glucose

50

Insulin

Transforms glucose to glycogen

51

Describe the sequence of events that occur during glycolysis

Glucose releases ATP, glucose transformed to 2x pyruvic acid - lactic acid and acetyl coenzyme A.
Acetyl coenzyme a - oxaloetic acid to the citric acid (krebs) cycle. Producing oxidative phosphorylation, ATP, h20 and co2. Anaerobic process (no oxygen required)

52

Describe protein metabolism anabolism?

Amino acids used to form new proteins

53

What is glycolysis?

Glucose broken down to form energy

54

Describe protein metabolism, catabolism?

Amino acids can enter TCA cycle,
Deaminated by removal of NH2 (ammonia) - toxic substance converted to urea by the liver and excreted in the urine

55

In the presence of oxygen begat happens to pyruvic acid?

Passes into the mitochondrion to enter the TCA cycle and the electron transport chain - produces 36 ATP

56

How many ATP are left altogether from glycolysis and the TCA cycle with electron transport chain?

38

57

Describe lipid metabolism - anabolism?

Fatty acids and glycerol converted to triglycerides
Lipogenesis - triglycerides formed from amino acids and glucose

58

Describe lipid metabolism - catabolism?

Lipolysis - breaking down fat for fuel eg
Glycerol - glycolysis
Fatty acids - acetyl co a - TCA cycle

59

The absorptive metabolic state occurs when and is what process?

Up to 4 hours after a meal
Mainly anabolic

60

The post absorptive metabolic state occurs when and is a mainly what process?

From 4 hours after meal to next meal
No absorption occurring
Mainly catabolic processes

61

What is normal blood plasma glucose?

3.5 - 8.0 mmol/L

62

What is normal fasting blood plasma glucose?

3.5-5.5mmol/L

63

Glycogenesis is?

Syntheses of glycogen from glucose

64

Glycogenolysis is?

Breakdown of glycogen into glucose

65

Gluconeogenesis is?

Synthesis of glucose from amino acids

66

What happens to glucose in the absorptive state?

Blood glucose is high - insulin is secreted by beta cells of pancreas, insulin lowers blood glucose by increasing entry of glucose into cells (increase carriers for facilitated diffusion), stimulating glycogenesis, stimulating fat and protein synthesis, inhibiting gluconeogenesis

67

What is the aim during the post absorptive state?

Prevent blood glucose falling

68

Name the 3 hormones involved in maintaining blood glucose levels during the post absorptive state?

Glucagon, adrenaline and glucocorticoids.

69

Where is glucagon secreted?

Pancreatic alpha cells

70

What does glucagon stimulate?

Glycogenolysis, gluconeogenesis and lipolysis

71

Where is adrenaline released?

SNS and adrenal medulla

72

What does adrenaline stimulate?

Glycogenolysis and lipolysis especially during injury, fear and stress.

73

Where are glucocorticoids such as cortisol and cortisone released?

Adrenal cortex

74

What do glucocorticoids stimulate?

Gluconeogenesis

75

When are ketones formed?

When the liver breaks down fats into proteins
Too much acetyl co a to enter TCA cycle so is converted to ketone bodies

76

What do some cells such as the heart and kidney use ketones for?

Energy

77

Too many ketones leads to what?

Ketoacidosis

78

What else can lead to ketoacidosis?

Lack of insulin in diabetes patients

79

What does insulin do to blood glucose?

Decrease it

80

What does glucagon do to blood glucose?

Increase blood glucose

81

What are the risk factors for gestational diabetes?

High BMI
Previous big baby
Close relative with diabetes
Previous gestational diabetes

82

How can gestational diabetes be controlled?

Diet and exercise
May need oral hypoglycaemia or insulin

83

Explain type I diabetes mellitus

Insulin - dependant diabetes
Children and young adults
Absence of insulin secretion
Autoimmune mechanism

84

Explain type II diabetes mellitus

90% of cases
Obesity, lifestyle, age, genetic factors
Diet and or drugs for treatment

85

List 8 essential acids

Histadine, luecine, lycine, methionine, phenylalanine, threonine, triptofan, valine