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Flashcards in Exam Revision Deck (227):
1

What are the 3 secondary structures?

Alpha helix

Beta sheet

Beta bend

2

What is the charge of acidic side chains?

Negative

3

What is the backbone of DNA called?

Deoxyribose-phosphate backbone

4

What joins amino acids together?

Peptide bonds

5

What are the different protein structures?

Primary

Secondary

Tertiary

Quarternary

6

What is the process of forming glycoproteins called?

Glycosylation

7

What is collagen composed of?

(glycine - x - proline)n

 

Where x can be:

Alanine

Hydroxyproline

Lysine

8

What percentage of body weight does water make up?

60%

9

What is the cytoskeleton made of?

Microfilaments

Intermediate filament

Microtubules

10

Whare are microfilaments made of?

Actin

11

What are intermediate filaments made of?

Fibrous proteins

12

What are microtubules made of?

Tubulin

13

What is the difference between trans and cis?

Cis is symettrical

14

What is the KW of water?

1 x 1014 mol/L

15

What are examples of important buffers?

Bicarbonate

Phosphate

16

How much Na and K does each molecule of ATP allow through the pump?

3 Na

2K

17

What is the osmolarity of the plasma?

385 mOsmols/L

18

What is the difference between the absolute refractory period and the relative refractory period?

Absolute is when all gates are opened and excitability is low

Relative is when gates are closed and excitability is increasing

19

What are examples of alpha, beta and C waves?

Alpha - proprioception, touch, fast pain

Beta - preganglionic autonomic fibres

C - heat, slow pain

20

What is acetylcholine removed from the NMJ by?

Acetylcholinesterase

21

What is the cofactor?

Non protein component needed for activity

22

What is the co enzyme?

Complex organic molecule usually produced from a vitamin

23

What is FAD derived from?

Riboflavin

24

What is NAD derived from?

Niacin

25

What is the prosthetic group?

Cofactor covalently bound to enzyme

26

What is the apoenzyme?

Protein component of enzyme that contains a cofactor

27

What is the difference between lyases and ligases?

Lygases form or add to double bonds

Liases form C-C, C-S, C-O or C-N bonds

28

Where is hexokinase and glucokinase found?

Glucokinase - liver

Hexokinase - everywhere else

29

What is KM and what does it indicate?

Concentration of the substrate at half the max v

 

High KM indicates a low affinity

30

What do the X and Y intersections on a Lineweaver-Burk plot represent?

Y - 1/vmax

X - 1/KM

31

What can you say about the first and second steps on an enzyme controlled reaction?

First is reversible

Second is rate limiting

32

What is an example of an enzyme that uses a sequential mechanism?

Lactate dehydrogenase (pyruvate to lactate)

33

What is an example of an enzyme that uses a random sequential mechanism?

Creatine kinase (creatine to phosphokinase)

34

What is an example of an enzyme that uses no ternary complex formation?

Asparate aminotransferases

35

What is used to show enzyme mechanisms?

Cleland notation

36

What is connective tissue composed of?

Ground substance

Collagen

Elastin

37

What is the ground substance composed of?

Glycoproteins and carbs

38

Where are desmosome junctions found?

Cardiac muscle

Bladder

39

Where are tight junctions found?

Intestine and stomach

40

Where are gap junctions found?

Cardial and neurons

41

What is the basement membrane composed of?

Basal lamina

Reticular lamina

42

What is the basal lamina?

Secreted by epithelial cells which they sit on

43

What is the reticular lamina?

Connects basal lamina to underlying connective tissue

44

What are the 2 kinds of glands?

Exocrine

Endocrine

45

What do exocrine glands do?

Secrete into tubes

46

What do endocrine glands do?

Secrete into the blood

47

What are the 2 kinds of ducts from exocrine glands?

Simple (unbranched)

Compound (branched)

48

What are the 2 kinds of excretory components of exocrine glands?

Tubular

Accinar

49

What are the 3 kinds of secretion from a gland?

Merocrine

Apocrine

Halocrine

50

What is merocrine?

Exocytosis

 

51

What is apocrine?

Discharge vesicles

Example is sweat glands

52

What is halocrine?

Discharge whole cell

Example is sebaceous gland

53

What cells produce the secretions within glands?

Myoepithelial cells once they contract

54

What is the thyroid gland special?

Contains follicles of hormones (thyroxine) which is reabsorbed before being released into the blood

55

What is a single celled gland?

Goblet gland

56

What are examples of exocrine organs?

Liver

Major silival gland

57

What are examples of endocrine organs?

Thyroid

Adrenal

58

What is the pancreas an example of?

An endocrine and exocrine organ

59

What is an example of loose connective tissue?

Adipose

60

What are the 3 components of connective tissue?

Fibres

Tissue fluid

Ground substance

61

What are examples of different collagens and where are they found?

Type I in tendons

Type III in reticular lamina

Type IV in basil lamina

62

What is collagen and elastin secreted by?

Connective tissue

63

What does loose connective tissue do?

Attach epithelial to underlying tissue

64

What are 4 cells permanent cells in loose connective tissue?

FIbroblasts

Macrophages

Adipocytes

Mast cells

65

What is an example of a dense regular connective tissue?

Tendons

66

What is an example of a dense irregular connective tissue?

Subacceous gland

67

What are some proteins usually coupled to G proteins?

Adrenylyl cyclase

Phospholipase C

68

Where is Ca stored?

Endoplasmic reticulum

69

What is EC50?

Concentration of a drug to produce half the maximum effect

70

What are fibrous joints made of?

Dense fibrous connective tissue

71

What are the 4 basic cells in the epidermis?

Dendritic cells

Karatinocytes

Melanocytes

Merket cells

72

What are merkel cells?

Touch receptors

73

What are the 5 layers of the epidermis?

Stratum basule

Stratum spinosum

Statum glanulosum

Stratum lucadum

Stratum corneum

74

What happens in the stratum basule?

Continuous proliferation

75

What happens in the stratum spinosum?

Cells shrink

Desmosome junctions create 'spikes'

76

What is in the statum granulosum?

Granules of keratohyaline

77

What happens in the stratum lucadum?

Conversion of keratohyaline to keratine

78

What is unique about the statum corneum?

No organelles

79

Where are melanocytes and merkel cells?

Stratum basule

80

What binds cells of the stratum basule to the basement membrane?

Hemidesmosomes

81

What gives strength to the stratum lucidum?

Disulphide bridges

82

What are the 2 layers of the dermis?

Papillary layer

Reticular layer

83

What is the papillary layer?

Loose connective tissue that protects against pathogens

84

What is the reticular layer?

Dense irregular connective tissue that attaches the skin to underlying tissues

85

What is found in the papilary layer?

Macrophages

Blood vessels

Nerve endings

86

What is unique about the subbaceous gland?

Only gland to secrete directly into the hair follicle

87

What are the 3 important hexoses?

Glucose

Fructose

Galactose

88

What are disaccharides linked by?

Glycosidic bonds

89

What is the only carbon that can be oxidised?

Anomeric carbon 

90

What are 3 important dissacharides?

Maltose

Lactose

Succrose

91

What is maltose formed from?

Glucose and glucose

92

What is lactose formed from?

Glucose and galactose

93

What is succrose formed from?

Glucose and fructose

94

What are the 2 glucose monomers in starch?

Amylase (alpha 1-4)

Amylopectin (alpha 1-4 and alpha 1-6)

95

What are glycoaminoglycans?

Unbranched polymers made from repeating units of hexuronic acid and an amino sugar

96

What is a property of glycaaminoglycans and where are they found?

Sticky and slimy, found in synovial fluid

97

What is a proteoglycan?

Formed from GAGs and proteins, more carbs than protein

98

What are mucopolysaccharides?

Genetic disorders caused by absence of the enzyme that breaks down glucoaminoglycans (GAGs)

99

Where are carbohydrates digested?

Mouth

Jejanum

Duodenum

100

What enzyme acts on carbohydrates in the mouth?

Silivary amylase which breaks down alpha 1-4

101

What is the breakdown of carbohydrates like in the duodenum?

Similar to the mouth

102

What are some enzymes that break down carbohydrates in the jejunum?

Isomaltose (hydrolyses alpha 1-6)

Glucamylase (removes glucose from non reducing end)

Sucrase (hydrolysis succrose)

Lactase (hydrolysis lactase)

 

103

How is glucose absorbed?

Driven by Na pump:

 

1) Taken into gut epithelium by glucose transporter (2Na and 1 glucose in)

2) Passes down concentration gradient into the blood

104

What can you say about cellulose and hemicellulose?

Cannot be digested so are broken down by gut bacteria, producing methane and hydrogen (smelly farts)

105

What is glucose immediately changed into in the liver and why?

Glucose-6-phosphate so it doesnt leave the cell

106

What is the reaction of glucose to glucose-6-phosphate controlled by?

Glucokinase in the liver

Hexokinase everywhere else

107

What controls the reaction of glucose-6-phosphate to glucose?

Glucose-6-phosphatase

108

What is the process of the synthesis of glycogen?

1) Glycogenin covalently binds glucose from uracil diphosphate (UDP) glucose to form a chain of about 8 monomers

2) Glycogen synthase extends the chain

3) Glycogen branching enzymes break chain and reattach alpha 1-6

4) Glycogen synthase takes over again

109

What is the process of the degradation of glycogen?

1) Glucose monomers removed 1 at a time from non reducing end by glycogen phosphorylase to produce G-1-P

2) Branch removed by debranching enzyme

a) Transferase removes 3 glucose monomers and attaches them to nearest non-reducing end by alpha 1-4 bond

b) Glucosidase removes final glucose monomer by breaking alpha 1-6 and releasing a free glucose

3) Process repeats

110

What are the 2 phases of glycolysis?

Preparative phase (2 molecules of G-3-P produced from G-6-P, using 2 ATP)

Payoff phase (1 molecule of pyruvate made per G-3-P, making 4 ATP)

111

What are the 3 steps of glycolysis that are irreversible?

Step 1 (glucose to glucose-6-phosphate)

Step 3 (F-6-P to F-1,6,bisP)

Step 10 (transfer of P from PEP to ADP, producing pyruvate)

112

What is the first commited step of glycolysis?

Step 3 (F-6-P to F-1, 6bisP)

113

What do all fates of glycolysis regenerate?

NAD

114

What enzyme controls the reation of pyruvate to lactate?

Lactate dehydrogenase

115

What happens to lactate at the end of the cori cycle?

Transfered to liver and convered to pyruvate for gluconeogenesis

116

Where does glycolysis happen?

Cytoplasm

117

Where does the reaction pyruvate to acetyl coA happen?

Mitochondria

118

Where is the enzyme that controls pyruvate to acetyl coA?

Pyruvate dehydrogenase

119

What are tissues that completely rely on glycolysis?

Brain

Nervous tissue

RBCs

Testis

Embryonic tissue

120

What is the reaction gluconeogenesis uses to bypass step 10 of glycolysis?

1) Pyruvate to oxaloacetate (controled by pyruvate carboxylase)

2) Oxaloacetate to PEP (controlled by PEP carboxylase)

121

Where is G-6-P converted into glucose?

Endoplasmic reticulum (G-6-P shuttled in and glucose and Pi shuttled out)

122

What enzyme controls F-1,6-bisP to F-6-P?

Fructose-1,6-biphosphotase

123

Where can fructose enter glycolysis?

Liver (dihydroxyacetone phosphate (DHAP) or glyceraldehyde - phosphate (GAP))

Adipose tissue (F-6-P)

124

Where can galactose enter glycolysis?

G-6-P

125

What does the pentose phosphate pathway produce?

Pentose

NADPH

126

What are the 2 stages of the pentose phosphate pathway?

1) Oxidation (irreversible)

2) Non oxidation (reversible)

127

What happens in the oxidation stage of the pentose phosphate pathway?

1) Generates NADPH

2) Converts G-6-P to pentose phosphate

128

What happens in the non oxidative stage of the pentose phospahte pathway?

Produces lots of 3, 4, 5, 6, 7 carbon sugars

129

What does breaking ethanol down require?

NAD

130

What do low levels of NAD lead to?

Increased blood lactate

Decrease blood glucose

131

What is vitamin C?

Monosaccharide

132

Where does the CIC happen?

Mitochondrial matrix

133

What does the CAC do?

Removes electrons from intermediates and passes them onto NAD and FAD

Each time 2C enters (acetly coA) and 2C leaves

134

What is pyruvate dehydrogenase inhibited by?

Acetyl coA

ATP

NADH

135

What is pyruvate dehydrogenase activated by?

Pyruvate

ADP

136

What are the enzymes that control the 2 irreversible steps in the CAC?

Isocitrate dehydrogenase

a-ketoglutamate dehydrogenase

137

Which of NADH and FADH2 cannot cross the mitochondrial membrane?

NADH cannot

138

How does NADH in the cytoplasm pass its electrons into the electron transport chain?

Glycerol phosphate shuttle

139

What is the process of the glycerol phosphate shuttle?

1) NADH passes electrons onto dihydroxyacetone phosphate which becomes glycerol-3-phosphate

2) Crosses outer membrane and passes electrons onto FAD which becomes FADH2

3) Enters electron transport chain

140

How many proteins are in the electron transport chain?

4

NADH-Q Oxidoreductase

Succinate-Q Reductase

Q-Cytochrome C Oxidoreductase

Cytochrome C Oxidases

141

What does the first protein of the ETC do?

Oxidise NADH and pass electons onto ubiquinone which becomes ubiquinol

Pumps H+ into intermembrane space

Uses Fe-S centres

142

What does the second protein of the ETC do?

Oxidises FADH2 and passes its electrons onto ubiquinone which becomes ubiquinol

Fe-S centres

Haem group captures stray electrons

143

What does the third protein of the ETC do?

Transfers electrons from ubiquinol to cytochrome C

Pumps protons into intermembrane space

144

How much cytochrome C does 1 ubiquinol make?

2 molecules

145

What does the fourth protein of the ETC do?

Passes electrons from cytochrome C to O2

Pumps protons into intermembrane space

Fe-Cu centres

146

What proteins of the ETC pump protons?

1, 3 and 4

147

What are the 2 parts of ATPsynthase?

F0 (membrane bound protein)

F1 (protrudes into mitochondrial matrix)

148

How many subunits does F0 have?

10

149

What is the process of ATPsynthase?

1) ADP and Pi enter beta subunit of F1

2) Rotation of F0 and gamma shaft causes conformation change in beta subunit

3) Catalysis ADP and Pi to ATP

150

When does ATPsynthase rotate?

When 3 H+ enters

151

How much H+ is needed to generate 1 molecule of ATP?

3

152

How much ATP does NADH and FADH2 generate

NADH generates 2.5 per molecule

FADH2 generates 1.5 per molecule

153

What does uncoupling of the ETC cause?

Generation of heat instead of energy, as seen in brown fat

154

What are the 5 classes of lipids?

Fatty acids

Triacyglycerols

Phospholipids

Glycolipids

Steroids

155

What is an example of lipid naming?

18:3 (9, 12, 15) 

18 carbon long, 3 double bonds after carbon 9, 12 and 15

156

Why can essential fatty acids not be synthesised?

We cannot intoduce double carbon bonds after carbon 9

157

What is omega 3 derived from?

Linolenic acid

158

What is digestion of lipids by pancreatic enzymes (lipases) promoted by?

Emulsufication by bile salts and peristalsis

159

What are bile salts a derivitive of?

Cholesterol

160

What is triacyglycerol degraded to in the small intestine?

2 fatty acids and a monoacylglycerol

161

What is cholesterol digested into?

Cholesterol and a fatty acid

162

What are phospholipids digested into?

Lysophospholid and a fatty acid

163

What is the process of digesting lipids?

1) Fats become emulsified in duodenum due to bile

2) roken down into fatty acids and glycerol in small intestine

164

What is the uptake of digested lipids in the small intestine?

1) Forms micelles with bile salt, which releases the lipids near the membrane which diffuse accross

Short and medium chain fatty acids do not need micelles

165

What happens to lipids that have been absorbed in the small intestine?

1) Resynthesised by intestinal epithelium cells for export

2) Packaged with apoB-48 into chylomicrons

3) Released by exocytosis into the lymph and then the blood

166

What happens to chylomicrons once they reach tissue?

1) Hydrolysid to fatty acid and glycerol by lipoprotein lipase

2) Used for energy or reesterfication to triacyglycerol for storage

167

What happens to chylomicron renmants?

Go to the liver where glycerol is used to produce glycerol-3-phosphate

168

What causes fatty acid to be released from adipose tissue?

Hormone sensitive lipase being activated by noradrenaline

169

What is hormone sensitive lipase deactivated by?

High plasma glucose

Insulin

170

What are examples of lipoproteins that carry lipids in the blood?

Chylomicron

VLDL

LDL

HDL

171

What is VLDL do?

Transfers tracyglycerol from liver to tissue

172

What does beta oxidation produce?

Acetyl coA

FADH2

NADH

173

Where does beta oxidation occur?

Mitochondrial matrix

174

What are the 3 stages of beta oxidation?

1) Activation of fatty acid in cytosol

2) Transport into mitochondria

3) Degradation to acetyl coA

175

What do fatty acids form when they are activated and what enzyme controls this?

Fatty acid and acetly co A becomes fatty acyl coA (enzyme is acyl coA synthase)

176

What does fatty acid use to enter the mitochonrial matrix?

Carnitine shuttle

177

What is the process of the carnitine shuttle?

1) Carnitine reacts with fatty acyl coA to produce acyl carnitine which crosses membrane

2) Acyl carnitine reacts with coA to produce fatty acyl coA

3) Carnitine returns to cytosol

178

What are the enzymes used in the carnitine shuttle?

Carnitine palmityl transferase I and II

179

What inhibits carnitine palmityl transferase?

Malonyl

180

What does not need to use the carnitine shuttle?

Short and medium chain fatty acids

181

What does each stage of beta oxidation produce?

1 acetyl coA

Carbon species 2 shorter

1 NADH

1 FADH2

182

What is the net yield of ATP for beta oxidation?

129 molecules

183

What happens when you are starving?

1) Liver flooded with acetyl coA

2) Inhibits pyruvate dehydrogenase and activates pyruvate carboxylase (pyruvate to oxaloacetate)

3) Produces glucose through gluconeogenesis

184

What is excess acetyl coA converted into?

Ketones

185

Where are ketones made?

Mitochondrial matrix of liver

186

What cannot use ketones for energy?

Liver

187

What cannot use fatty acids for energy?

Brain

188

Where does fatty acid synthesis occur?

Cytosol

189

How does acetyl coA get to the cytosol for fatty acid synthesis?

Citrate shuttle

190

What is the process of the citrate shuttle?

1) Acetyl coA reacts with oxaloacetate to become citrate which crosses the membrane

2) Citrate broken down to acetyl coA and oxaloacetate in cytosol

3) Oxaloacetate uses NADH to become malate

4) Malate uses NAD to become pyruvate to cross into matrix

5) Pyruvate converted to oxaloacetate

191

What is produed in the citrate shuttle?

NADPH which is used later for fatty acid synthesis

192

What is the product of fatty acid synthesis?

Palmitic acid

193

What is the rate determining step in fatty acid synthesis?

Acetyl coA and ATP to melonyl coA (catalysed by acetyl coA carboxylase)

194

What is acetyl coA carboxylase activated and inhibited by?

Activated by insulin

Inhibited by palmitoyl coA, glucagon and noradrenaline

195

How much NADPH does the formation of palmitic acid uses and where does it come from?

14 from citrate shuttle and pentose phosphate pathway

196

What are some specialised lipid classes?

Steroid hormones

Cholesterol

Eicosanoids

197

What is cholesterol used to make?

Steroid hormones and membranes

198

What are eicosanoids derived from?

Omega 3 and omega 6

199

What does nitrogen to other molecule flow through?

Glutamate

200

What is transanimation?

Transfering amino groups through different molecules

201

What do all amino transfers rely on?

Pyridoxal phosphate cofactor (transfers amino group, derived from vitamin B6)

202

What is the proces of dietry proteins being broken down?

1) Pepsin cuts proteins into peptides in the stomach

2) Trypsin and chymotrypin cut proteins and large peptides into smaller peptides in the small intestine

3) Aminopeptidases and carboxypipdases A and B degrade peptides into amino acids in small intestine

203

What tages cellular proteins that are to be degraded?

Ubiquione

204

What are the fates of amino acids?

Left in tack for biosynthesis

Broken down into carbon skeleton and amino group

205

What is the fate of an amino group from a broken down protein?

Nitrogen disposed by urea cycle

206

What are the possible fates of carbon skeletons?

Glucose or glycogen synthesis

Cellular respiration

Fatty acid synthesis

207

What is amonia transported through the bloodstream as?

Glutamine

208

What is pyruvate converted into once it donates it accepts an amino group?

Alanine

209

What is the pyruvate - alanine cycle?

1) Protein broken down in exercise if required

2) Transported to liver as alanine

3) Carbon skeleton converted to pyruvate

4) Nitrogen excreted as ammonia in urine

5) Pyruvate to oxaloacetate to glucose (gluconeogensis)

210

What are the 2 nitrogen acquiring reactions of glutamate being broken down in the liver?

1) Synthesis of carbamoyl phosphate

2) Entry of asparate into urea cycle

211

How many amino acids are essential?

8

212

What are the 2 kinds of carbon skeletons?

Glucogenic (feeds into gluconeogenesis)

Ketogenic (feeds into CAC)

213

Where does the urea cycle happen?

Split between mitochondrial matrix and cytosol

214

What goes in and out of the urea cycle?

Ammonia goes in and urea comes out

215

How many enzymes are involved in the urea cycle?

6 enzymes

216

What is the most common urea cycle defect?

UTC difficiency (X linked)

217

What is PKU?

Absence/difficiency of phenylalanine hydroxylase, causing a build up of phenylalanine levels which is toxic

218

What receptors does the autonomic and somatic nervous systems use?

Somatic uses iatotropic

Autonomic uses metatropic (G proteins)

219

What kinds of receptors does acetylcholine act on?

Cholinergenic:

 

Nicotinic (2)

Muscarinic (3)

220

What receptors does noradrenaline act on?

Adrenic:

 

Alpha (2)

Beta (3)

221

How does the adrenal medulla work?

Sympathetic fibres innervate it and cause it to release adrenaline and noradrenaline into the blood

222

What are examples of post ganglionic fibres not following the rules?

Sympathetic cholinergic fibres innervate sweat glands

Some release neurotransmitters like peptides or NO

223

What is an example of antagonistic innervation of the autonomic nervous system?

Eye

224

What is an example of single innervation of the autonomic nervous system?

Energy stores

225

What is an example of dual innervation with non-antagonistic actions of the autonomic nervous system?

Salivary glands

226

What is an example of dual innervation with complimentary effects of the autonomic nervous system?

Reproductuve tract

227

What controls the autonomic nervous system?

Hypothalamus

Reflexes