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Flashcards in Biochemistry Deck (151):
1

Define the Cori cycle

Glycogen => glucose => lactate in muscle Lactate travels to liver Lactate => glucose in liver Glucose goes back to muscle => glycogen

1

Which vitamin is niacin?

B3

1

What are the 3 ketone bodies?

Beta-hydroxybutyrate Acetone Acetoacetate

2

How many ATP are produced for each NADH?

2.5

3

What does VItC deficiency cause?

Survy

4

What is the major determinant of glycogen glucose conversion?

Insulin: glucagon ratio

4

What is the cutoff for waist circumference for greatly increased risk of metabolic complications for females?

>= 88

4

What happens to leptin in obesity?

There is a decreased sensitivity to leptin, but increased amounts of leptin

4

Which cells secrete CCK?

I cells of the small intestine

5

In what part of the cell does beta oxidation occur?

MItochondria

5

How many H+ are put into the intermembrane space for each NADH molecule?

10

5

How many H+ are put into the intermembrane space for each FADH2 molecule?

6

5

Which vitamin is riboflavin?

B2

5

What is the key sign for VitB2 deficiency?

Magenta tongue

5

What are the 4 Ds of pellagra?

Photosensitive dermatitis. Diarrhoea. Dementia. Death

5

What is the range for BMI to be obese?

>30

5

What is the cutoff for waist circumference for increased risk of metabolic complications for males?

>= 94cm

6

Where does vitamin K come from?

It is produced by gut flora

7

Where do we get intrinsic factor from?

It is synthesised by parietal cells of the stomach

7

Deficiency of which vitamin will cause xerophthalmia?

VitA

7

Why is VitC often given with iron supplements?

VitC reduces Fe3+ to Fe2+, which is better absorbed

8

How do RBCs produce most of their energy?

Anaerobic glycolysis

9

Which cells release insulin?

Beta cells of the islets of Langerhans of the pancreas

10

What is the advantage of chylomicrons from the gut travelling through lymphatics to reach blood?

It bypasses the liver

11

Where and in which order is VitD hydroxylated?

Skin => liver => kidney

11

What is transported into cells with glucose via GLUT-4 transporters?

Potassium

12

What disease will deficiency of niacin cause?

Pellagra

13

What is the most abundant mineral in the human body?

Calcium

14

What are the 3 defining features of a vitamin?

Organic compound Not made by the body Essential biochemical funcitons

14

Where is ghreline released?

Stomach

15

Which organs have glucose-6-phostphatase?

Liver and kidney

15

Which vitamin is pyridoxine?

B6

16

What happens when muscles release excessive calcium and become an uncontrolled ATPase?

Malignant hyperthermia

17

What inhibits carnitine acyl transferase 1?

Malonyl CoA

18

What happens to insulin levels in starvation?

Decrease

18

What causes Wilson's disease?

Excess copper

20

What is the classic triad of symptoms for diabetes?

Polydipsia, polyphagia polyuria

20

What happens to glucose in the liver when glycogen stores are saturated?

Glucose is converted to fatty acids

22

What do muscles use for fuel with bursts of heave activity eg 50m sprint?

Phosphocreatine

22

Which vitamin is thiamine?

B1

22

What is the significance of glycogen being insoluble?

Exerts little osmotic effect

23

How many phases of insulin release are there after a meal?

2

24

Name 3 consequences of calcium deficiency

Rickets. osteoporosis and poor blood clotting

25

Which organelle is an endosymbiotic bacteria?

Mitochondria

26

In disease of which organelle do we often see ragged red fibers?

Mitochondria

27

Which enzyme allows the liver to export glucose to the blood?

Glucose-6-phosphatase

28

How long will glycogen reserves last in the fasting state with relative inactivity?

12 hours

29

Which enzyme converts glycogen => glucose-1-phosphate

Glycogen phosphorylase

30

What is a typical daily dietary energy requirement for an adult?

10 MJ

30

How much protein do we make and break down every day?

300g

31

What is the range for BMI to be underweight?

32

Where is ammonia processed into urea?

Liver

33

What does excessive iron cause?

Haemochromatosis

35

What is at the core of glycogen?

Glycogenin

36

The levels of which hormone increase just befor a meal?

Ghrelin

37

Which monosaccharide(s) are aldoses?

Glucose and galactose

38

What are the side effects of orlistat?

Explosive diarrhoea. Steatorrhea

39

Release of which hormone is stimulated by hyperglycaemia?

Insulin

41

In what part of the cell does glycolysis occur?

Cytosol

41

What is another name for dextrose?

Glucose

43

What are the two major families of sugars?

Aldose and ketose

45

Which monosaccharide(s) are ketoses?

Fructose

46

What will happen if there are too many free fatty acids in the blood that are not bound to albumin?

Arrhythmia

47

Release of which hormone is stimulated by hypoglycaemia?

Glucagon

48

How many molecules of ATP are yielded from aerobic metabolism of 1 glucose molecule?

30 or 32

49

What is the range for BMI to be morbidly obese?

>40

51

What diseases will insufficient thiamin cause?

Beriberi and Wernicke's Encephalopathy

53

Which glucose transporter does insulin upregulate?

GLUT-4

55

Which fuel source is premium during starvation?

Fat

56

Which hormone does ghrelin antagonise?

Leptin

57

Why can't humans digest cellulose?

Don't have an enzyme to break the beta 1,4 bonds

58

Where in the cell does ketone acid synthesis occur?

Mitochondria

59

What mediates the effects of ghrelin?

Neuropeptide Y

61

Which vitamin is a cofactor in collagen synthesis?

VitC

62

What part of triacyglycerols can be used to make glucose?

Glycerol

64

Which pathway is VitK important for?

Coagulation cascade

65

What is a biochemical role of thiamine?

It is a co-factor for pyruvate decarboxylase (pyruvate => Acetyl CoA)

66

Glucose is all ___ ____ _____ .

Glucose is all D except 3

68

What is the order of B vitamins?

Thiamine. Riboflavin. Niacin. Pyridoxine. Cobalamin. The rich never park cars

69

Which vitamin is cobalamin?

B12

70

What would happen if you gave GLP-1 with food?

You would feel more full and eat less

72

What is the cutoff for waist circumference for increased risk of metabolic complications for females?

>= 80cm

74

What percentage of Australians are overweight or obese?

63%

75

How is VitB12 absorbed?

With intrinsic factor in the terminal ileum

76

Which two drugs are TGA approved for treatment of obesity?

Phentermine and orlistat

77

How is BMI calculated?

weight (kg) / height (m)^2

78

Why can't the brain use fatty acids for energy?

FAs can't cross BBB

79

What condition is caused by a diet that is severely deficient in energy and moderately deficient in protein?

Marasmus

80

How do fatty acids get into the mitochondria?

Carnitine acyl transferase

81

What effects may VitB12 deficiency have?

Dementia. Pernicious anaemia.

82

In starvation, what can fatty acids be turned into?

Ketones

84

What happens to sperm mitochondria at fertilisation?

They are discarded

85

What effect does adrenaline have on carbohydrate metabolism in the liver?

Causes catabolism of glycogen into glucose

87

Which nucleus of the hypothalamus does ghrelin stimulate?

Arcuate nucleus

88

How does phentermine treat obesity?

Sympathomimetic => supresses appetite

90

Which cells produce leptin?

Adipocytes

91

What is the preferred fuel for skeletal muscle?

Glucose

92

What is the cutoff for waist circumference for greatly increased risk of metabolic complications for males?

>= 102

94

Which vitamin will you run out of first if you stop eating?

Thiamine (VitB12)

95

Which protein causes uncoupling in brown fat?

Thermogenin

95

Which vitamin is niacin?

B3

96

What disease causes engorged lysosomes full of glycogen due to a deficiency of alpha 1,4 glucosidase?

Pompes diseases

98

What causes pellagra?

Insufficient VitB3 (niacin)

99

Which organs express GLUT4?

Muscle, adipose tissue and heart

100

How does orlistat treat obesity?

It is a lipase inhibitor => inhibits absorption of fat

102

What is created when electrons escape from the electron transport chain?

Reactive oxygen species

103

Why can't fatty acids be converted into glucose?

Can't convert acetyl CoA into pyruvate

105

What is starch?

A branched polymer of glucose found in many plants

106

What are the side effects of phentermine?

Increased HR and BP, anxiety, insomnia, dry mouth, headache

107

What does VitD deficiency cause in children?

Ricket's

108

How many mitochondria are there per cell?

200-10,000

109

How much glucose does the brain need per day?

120g

110

How long will thiamine reserves last if you stop eating completely?

2 weeks

111

How much energy is there per mol of ATP?

30.5 kJ

112

How are fatty acids transported in the blood?

Bound to albumin

113

How does the retina produce most of its energy?

Anaerobic glycolysis

114

After several days of starvation, what is the main source of carbon backbone for gluconeogenesis?

Glycerol from TAGs

115

Where in the body can fatty acids be used for gluconeogenesis?

NOWHERE

116

What effects may folate deficiency have?

Spina bifida in pregnancy. Macrocytic anaemia.

117

What is the range for BMI to be normal?

18.5-25

118

How many molecules of ATP are yielded from anaerobic metabolism of 1 glucose molecule?

2

119

What is the range for BMI to be overweight?

25-30

120

What is the alanine cycle?

Nitrogen from protein catabolism in muscle is transferred to liver in the form of alanine. The ammonia is transferred to urea for excreted

121

How many ATPs are net produced by glycolysis?

2

122

How does CCK stimulate satiety/fullness?

Via the vagus nerve

124

How many ATP are produced for each FADH2?

1.5

125

Which hormone does adipocytes release to signal fat storage levels?

Leptin

126

Which two substances can activate hormone sensitive lipase?

Glucagon and adrenaline

127

Which organs express GLUT2?

Liver, pancreas and GIT

128

Which organ expresses glucokinase?

Liver

129

What does hyperuricaemia cause?

Gout

131

Which cells release glucagon?

Alpha cells of the islets of Langerhans of pancreas

132

How do we describe a fatty acid when there is a double bond at the third carbon from the end of the hydrocarbon chain?

Omega 3

133

How much energy is there per mol of NADH?

2200 kJ

134

Which prostaglandin does omega 3 fatty acids promote the formation of?

Prostacyclin

135

What causes beriberi disease?

Insufficient VitB1 (thiamine)

136

Which cells release somatostatin?

Delta cells of the of the islets of Langerhans of the pancreas

137

What condition is caused by a diet that is severely deficient in protein?

Kwashiorkor

138

What effect does leptin have on appetite?

Decreases

139

Which conditions can fibre prevent?

Diverticulosis and haemorrhoids

141

What effect does somatostatin have on alpha and beta cells of the pancreas?

Decreases release of their hormones

142

How many nitrogen atoms are there in urea?

2

143

In what part of the cell does the Krebs cycle occur?

Mitochondria

144

What are the main sources of carbon for gluconeogenesis in starvation?

Glycerol and proteins

145

Which cells express GLUT1?

All cells

146

Which peptide is released by cleavage of pro-insulin (apart from insulin)?

C-peptide

147

How does the body get rid of nitrogen?

In urea or ammonia

148

What is the principal sterol synthesized by animals?

Cholesterol

149

Which reaction does phenylalanine hydroxylase catalyse?

Phenylalanine -> tyrosine

150

What is the precursor for cholesterol synthesis in the liver?

Acetyl Co-A

151

In which organelle is squalene converted to cholesterol?

Endoplasmic reticulum