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Phase 1 flashcards > IMMS > Flashcards

IMMS Flashcards

1
Q

Describe the features of the two types of chromatin

A

Tight coils of heterochromatin which are repressed
Loose coils of euchromatin which are expressed

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2
Q

Function of the nucleolus?

A

rRNA synthesis

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3
Q

Function of mitochondria

A

ATP synthesis

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4
Q

Function of SER

A

Membrane lipid synthesis
Protein storage
Phase 1 detoxification

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5
Q

Function of RER

A

Ribosomes on surface carry out protein synthesis

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6
Q

Function of the three parts of the Golgi

A

Cis - receives protein and lipid vesicles
Medial - adds sugar to these
Trans - packages modified molecules into vesicles to be exocytosed

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7
Q

What is a perinuclear hoff?

A

Visible circle of Golgi apparatus in plasma cells

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8
Q

Function of lysosomes

A

Contain hydrolysis enzymes that degrade proteins and carry out autolysis

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9
Q

What pH are lysosomes and how is this pH maintained?

A

5
H+/ K+ ATPases

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10
Q

Function of peroxisomes

A

Beta oxidation of of fatty acids
Produce and destroy hydrogen peroxide to form hydroxide ions
Removes hydrogen from lipid/ alcohol/ toxic substances

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11
Q

Microtubule diameter

A

25nm

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12
Q

Describe the structure of microtubules

A

Tubulin motor protein
Arranged as alpha and beta structure - a dimer

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13
Q

Function of microtubules

A

Mitosis
Component of cilia

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14
Q

Diameter of intermediate filaments

A

10nm

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15
Q

Do intermediate filaments have motor proteins?

A

No

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16
Q

Function of intermediate filaments

A

Cell integrity
Cell to cell contact

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17
Q

Diameter of microfilaments

A

5-7nm

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18
Q

Which motor protein is in microfilaments?

A

Myosin

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19
Q

Function of microfilaments

A

Cell shape and motility

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20
Q

Name some cell storage products

A

Lipofuscin, lipids, glycoproteins

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21
Q

What is lipofuscin, and how is it produced?

A

Wear and tear pigment
Oxidative lipid degradation
Produced in old cells

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22
Q

Colour of lipofuscin

A

Orangey brown

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23
Q

Staining of lipids

A

Pale/ white

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24
Q

What cells are lipids stored in, and in which other organ?

A

Adipocytes and in the liver

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25
Q

What are glycoproteins and where are they found?

A

Glucose reserves in skeletal muscle and the liver

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26
Q

Functions of cell membranes

A

Partially permeable
Boundary between the intracellular and extracellular space
Receptors for self
Link adjacent cells

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27
Q

How do cells act as receptors?

A

Outside binding triggers intracellular response

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28
Q

Describe G Coupled proteins

A

Extracellular binding activates transduction pathway internally
Cascade of internal reactions

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29
Q

Types of cell membrane channels

A

Ligand gated
Voltage gated
Mechanical gated (open when stretched)

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30
Q

Types of cell to cell junctions

A

Tight junctions
Adherens
Desmosomes
Gap junctions

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31
Q

Describe tight junctions

A

Prevent passage of substances between cells

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32
Q

Where are tight junctions found

A

GI tract
Blood brain barrier

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33
Q

Describe adherens

A

Adjacent actin
Bundles of cells joined

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34
Q

How do desmosomes work

A

Adjacent intermediate filaments joined

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35
Q

Describe gap junctions

A

Allow passage of ions between adjacent cells

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36
Q

In which organ are gap junctions important?

A

Heart
Myocardium - heart contracts as a synctium

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37
Q

What is
a) diffusion
b) osmosis
c) facilitated diffusion

A

a) movement of molecules down its concentration gradient
b) movement of water down its potential gradient across a partially permeable membrane
c) movement of molecules down a concentration gradient using a membrane protein

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38
Q

Describe active transport

A

Movement of molecules against a concentration gradient using energy

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39
Q

What is the difference between primary and secondary active transport?

A

Primary - e.g Na+/ K+ ATPase pumps - direct
Secondary - uses cotransport - indirect

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40
Q

What is exocytosis?

A

Vesicles bud off cell surface membrane and contents are released

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41
Q

What is endocytosis

A

Intake of molecules in phagosome vacuole

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42
Q

What is phagocytosis

A

Engulfing whole cells/ macromolecules by neutrophils/ macrophages

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43
Q

What is pinocytosis

A

Engulfing dissolved solutes

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44
Q

What is receptor mediated endocytosis

A

Engulfing ligand-receptor complexes

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45
Q

What is homeostasis

A

Maintenance of constant internal conditions within a normal range

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46
Q

What are the three modes of communication between cells

A

Autocrine
Paracrine
Endocrine

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47
Q

What is autocrine communication

A

Signalling molecule acts on the same cell
Secretion into ECF

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48
Q

What is paracrine communication

A

Signalling molecule acts on a nearby cell
Secretion into the ECF

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49
Q

What is endocrine communication

A

Signalling molecule acts on a distant target call by travelling in the blood

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50
Q

Give an example of a paracrine hormone

A

Ach at the nmj

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51
Q

Give an example of an endocrine hormone

A

ADH from posterior pituitary

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52
Q

What is negative feedback?

A

a highly regulated loop

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53
Q

what is positive feedback

A

not a loop
amplification e.g blood clotting

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54
Q

are peptide hormones water soluble

A

yes

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55
Q

do peptide hormones enter the cell or bind to the CSM

A

bind to the csm

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56
Q

are peptide hormones slow or fast acting

A

fast

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57
Q

are peptide hormones premade?

A

yes

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58
Q

what are steroid hormones made from?

A

cholesterol

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59
Q

are steroid hormones lipid or water soluble

A

lipid soluble

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60
Q

do steroid hormones enter the cell or bind to the CSM?

A

enter the cell by diffusing through the CSM

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61
Q

are steroid hormones slow or fast acting

A

slow

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62
Q

are steroid hormones premade?

A

no

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63
Q

give 2 examples of steroid and peptide hormones

A

oestrogen, testosterone
insulin, ADH

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64
Q

how much water is in the ICF?

A

28L

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65
Q

predominant electrolyte in the ICF?

A

K+

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66
Q

how much water is in the ECF

A

14L

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67
Q

how much water is in the interstitial fluid and plasma?

A

interstitial - 11L
plasma - 3L

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68
Q

predominant electrolyte in the ECF

A

Na+

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69
Q

what is sensible water loss?

A

can be measured easily

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70
Q

give an example of sensible water loss

A

urine, vomit

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71
Q

what is insensible water loss?

A

water loss that cannot be measured easily

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72
Q

give an example of insensible water loss

A

sweat, breath

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73
Q

what does RAAS stand for?

A

renin-angiotensin-aldosterone system

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74
Q

when is RAAS activated?

A

fall in blood pressure detected by baroreceptors in the afferent arteriole
fall in NaCl detected by macula densa of DCT

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75
Q

what enzyme is released to trigger RAAS

A

renin

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76
Q

where is renin released from

A

juxtaglomerular cells

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77
Q

what converts angiotensinogen to angiotensin I

A

renin

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78
Q

what converts angiotensin I to angiotensin II, and where is it produced

A

ACE, lungs

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79
Q

actions of angiotensin II

A

ADH release
- acts on aquaporin II on collecting ducts
- increases collecting duct permeability
- increased water retention
- increase in blood pressure as ECF increases
- made in hypothalamus and stored in the posterior pituitary gland
Aldosterone release
- from suprarenal cortex of adrenal gland
- increases Na+ reabsorption in ascending limb of LOH
- water follows Na+
- bp increases as ECF increases
Triggers the sympathetic nervous system

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80
Q

what are the roles of ANP

A

antagonist to aldosterone
decreases blood pressure

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81
Q

when is ANP released

A

when atria are stretched as a result of an increase in blood pressure

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82
Q

what does ANP stand for

A

atrial natriuetic peptide

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83
Q

what does excess water cause

A

oedema

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84
Q

what is osmolarity

A

number of solute particles per litre of solvent

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85
Q

what is osmolality

A

number of solute particles per kg of solvent

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86
Q

what is osmotic pressure

A

pressure exerted by a pure solvent on a solution needed to prevent inwards osmosis (solvent to solution)

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87
Q

oncotic pressure

A

pressure exerted by plasma proteins, notably albumin, on a capillary wall keeping fluid in

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88
Q

hydrostatic pressure

A

pressure that pushes fluid out of a capillary

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89
Q

what is hypernatremia

A

abnormally high sodium concentration in the blood

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90
Q

causes of hypernatremia

A

dehydration, an increase in aldosterone, kidney failure

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91
Q

symptoms of hypernatremia

A

oedema, an increase in blood pressure

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92
Q

what is hyponatremia

A

abnormally low sodium concentration in the blood

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93
Q

what causes hyponatremia?

A

excess water, a fall in aldosterone

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94
Q

symptoms of hyponatremia

A

a fall in blood pressure, over hydrated intracellularly

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95
Q

what is hyperkalaemia

A

abnormally high potassium concentration in the blood

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96
Q

what causes hyperkalemia

A

kidney failure, a fall in aldosterone, alkalosis

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97
Q

what are the symptoms of hyperkalemia

A

nerve and muscle weakness - regulation of the resting membrane potential

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98
Q

what is hypokalaemia

A

abnormally low potassium concentrations in the blood

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99
Q

what causes hypokalaemia

A

diarrhoea, acidosis, an increase in aldosterone

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100
Q

what are the symptoms of hypokalaemia

A

weakness, heart problems

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101
Q

what is hypercalcaemia

A

abnormally high calcium concentration in the blood

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102
Q

what causes hypercalcemia

A

an increase in parathyroid hormone, too much vitamin D (which absorbs calcium), skeletal metastasis

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103
Q

what are the symptoms of hypercalcemia

A

bone and muscle weakness, calcification

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104
Q

what is hypocalcemia

A

abnormally low calcium concentrations in the blood

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105
Q

what are the causes of hypocalcemia

A

a decrease in parathyroid hormone, not enough vitamin D, GI malabsorption

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106
Q

symptoms of hypocalcemia

A

muscle spasms (needed for action potentials)

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107
Q

general formula for carbohydrates

A

(CH2O)n

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108
Q

what are the divisions of carbohydrates

A

mono, di, oligo and polysaccharides

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109
Q

what is the range of the number of carbons an oligosaccharide can have?

A

3-10

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110
Q

what bonds join monosaccharides to form polysaccharides?

A

glycosidic

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111
Q

what bonds are found in lipids

A

ester

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112
Q

how are lipids oxidised

A

fatty acid beta oxidation

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113
Q

what does amphipathic mean?

A

having both hydrophilic and hydrophobic parts e.g phospholipids

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114
Q

lipid functions

A

protection from mechanical damage, lubrication, waterproofing, energy source

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115
Q

how much energy do lipids contain per gram

A

9kcal/g

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116
Q

what are the components of nucleotides?

A

phosphate, pentose sugar, organic nitrogenous base

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117
Q

what are the bonds between the bases of nucleotides

A

hydrogen bonds

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118
Q

what are the bonds between the phosphate and sugar in nucleotides

A

phosphodiester

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119
Q

which nucleotides are purines?

A

adenine and guanine

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120
Q

how many rings do purines have?

A

2

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121
Q

which nucleotides are pyrimidines

A

cytosine, thymine, uracil

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122
Q

how many rings do pyrimidines have?

A

3

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123
Q

how many hydrogen bonds are between A and T, and C and G

A

2, and 3

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124
Q

what is a nucleoside

A

pentose sugar and base (no phosphate)

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125
Q

how many essential amino acids are there?

A

8

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126
Q

what is the configuration of a peptide bond?

A

CONH

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127
Q

what affects the properties of an amino acid?

A

R group

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128
Q

what is the primary structure of a protein?

A

sequence of amino acid

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129
Q

what is the secondary structure of a protein?

A

twisting and folding of the polypeptide chain due to hydrogen bonds
forms alpha helices and beta pleated sheets

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130
Q

what is the tertiary structure of a protein?

A

3D folding due to ionic bonds, hydrophobic interactions and disulphide bridges

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131
Q

what is the quaternary structure of a protein?

A

more than one polypeptide chain

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132
Q

how do enzymes work?

A

alternative pathway for a reaction to occur, with a lower activation energy

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133
Q

what are coenzymes

A

organic molecule (non protein) that binds to proteins to aid function

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134
Q

does myoglobin have a higher of lower oxygen affinity than haemoglobin

A

higher

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135
Q

structure of haemoglobin (HbA)

A

2 alpha chains, 2 beta chains

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136
Q

structure of foetal haemoglobin

A

a alpha chains, two gamma chains

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137
Q

name of sickle haemoglobin

A

HbS

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138
Q

structure of HbS

A

2 alpha, 2 mutated beta

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139
Q

genetics of HbS

A

autosomal recessive
mutated beta chain on 11p (short arm)
GAG TO GTG (substitution)
glutamic acid to valine

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140
Q

how does HbS cause symptoms?

A

RBC SA decreases due to sickle shape
less flexible and more prone to damage

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141
Q

why is sickle cell more common in Africa

A

protects against malaria

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142
Q

function of DNA

A

stores genetic information

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143
Q

what is the term for three DNA bases vs 3 RNA bases?

A

DNA - triplet
RNA - codon

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144
Q

function of RNA

A

transfers genetic information

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145
Q

which base is substituted in RNA?

A

T substituted for U

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146
Q

which enzyme unwinds the supercoil?

A

topoisomerase

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147
Q

which enzyme breaks hydrogen bonds between the bases to separate the strands?

A

helicase

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148
Q

what are the three stages of DNA replication?

A

initiation, elongation and termination

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149
Q

what are SSBs

A

single stranded binding proteins
coat the single DNA strands to prevent reannealing or snapping back together

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150
Q

what direction does DNA polymerase read in?

A

3’ to 5’

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151
Q

what direction does DNA polymerase synthesise in?

A

5’ to 3’

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152
Q

what does DNA polymerase do?

A

forms phosphodiester bonds between free nucleotides to extend the strand

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153
Q

function of DNA ligase

A

joins Okazaki fragments on the lagging strand by phosphodiester bonds

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154
Q

where does transcription occur?

A

nucleus

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155
Q

stages of transcription

A

preparation, production, termination, modification (splicing)

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156
Q

what is transcription

A

synthesis of mRNA from DNA

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157
Q

describe the preparation stage of transcription

A

topoisomerase unwinds the double helix by relieving the supercoils
DNA helicase separates the DNA apart by exposing the nucleotides
SSBs coat the single DNA strands to prevent reannealing

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158
Q

which promoter sequence is the recognition signal for starting

A

TATA

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159
Q

what is the start codon, and what does it code for

A

AUG
methionine

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160
Q

in what direction does the coding strand run in?

A

5’ to 3’

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161
Q

in what direction does the template strand run in?

A

3’ to 5’

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162
Q

describe the production stage of transcription

A

TATA sequence is the recognition signal for starting
AUG is the start codon - codes for methionine
free mRNA nucleotides line up next to their complementary bases on the template strand/ antisense strand of DNA
U-T, C-G
coding strand runs 5’ to 3’
template strand runs 3’ to 5’
ends at the stop codon - UAA/ UAG/ UGA

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163
Q

function of RNA polymerase

A

joins mRNA nucleotides
catalyses the formation of phosphodiester bonds

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164
Q

describe the modification stage of transcription

A

splicing
removal of introns
leaves axons - the coding part

165
Q

how does mRNA leave the nucleus

A

nuclear pores

166
Q

where does translation occur?

A

cytoplasm

167
Q

which ribosome subunit does mRNA bind to?

A

small

168
Q

which ribosome subunit does tRNA bind to?

A

large

169
Q

what is the most common start codon?

A

AUG (methionine)

170
Q

what is the product of transcription?

A

PRE mRNA

171
Q

three bases on tRNA is called?

A

anticodon

172
Q

function of tRNA

A

carries amino acid to mRNA

173
Q

where does the polypeptide chain travel to after translation?

A

Golgi

174
Q

how many autosomal and sex pairs of chromosomes do we have?

A

22 autosomal pairs
1 sex pair

175
Q

where is DNA found in the cell?

A

nucleus and mitochondria (maternal)

176
Q

name the two cell cycle checkpoints

A

G1 and G2 checkpoints (at the end of these stages)

177
Q

name the stages of the cell cycle

A

interphase
-G1
-S
-G2
Mitosis
-PMAT
-cytokinesis

178
Q

function of G2 checkpoint

A

checks DNA damage pre mitosis
damaged base excision by glycosylases

179
Q

function of G1 checkpoint

A

checks DNA damage pre DNA replication
damage activates p53 tumour suppressor gene
p21 activated
autolysis

180
Q

what occurs during G1?

A

organelles replicate

181
Q

what occurs during S?

A

DNA replication
centrosome replication

182
Q

what occurs during G2?

A

chromosomes condense
mitochondria and centrioles double
energy stores accumulate

183
Q

what is G0?

A

normal function/ repair
some cells never leave this state e.g neurons
fully differentiated cells

184
Q

what happens during prophase?

A

centrioles move to poles and form spindle
chromosomes condense

185
Q

what happens during prometaphase?

A

centromeres bind to spindle via centromere
nuclear membrane breaks down
microtubules invade nuclear space

186
Q

what happens during metaphase?

A

chromosomes line up on equator

187
Q

what happens during anaphase?

A

sister chromatids separate and pulled to opposite poles of cell
V shape assumed

188
Q

what happens during telophase?

A

nuclear envelope reforms
chromosomes decondense into chromatin

189
Q

is cytokinesis part of mitosis?

A

yes, according to lectures even though some textbooks say no

190
Q

what happens during cytokinesis?

A

cell cytoplasm divides into two daughter cells

191
Q

difference between mitosis and meiosis

A

meiosis
- only in gametes
- recombination of genetic material for diversity
- two cell divisions
- 4 haploid daughter cells

192
Q

what happens in meiosis 2?

A

separation of sister chromatids

193
Q

what creates genetic variation in meiosis?

A

crossing over in prophase 1
independent segregation in metaphase 1

194
Q

when does spermatogenesis begin?

A

puberty, and continue afterwards

195
Q

is the cytoplasmic division in spermatogenesis even?

A

yes

196
Q

describe the stages of spermatogenesis

A

spermatogonia, primary spermatocyte, 2 x secondary spermatocytes, 4 spermatids (immature sperm), which differentiate into mature sperm (spermatozoa)

197
Q

what is the first meiotic division of spermatogenesis?

A

primary to secondary spermatocyte

198
Q

what is the second meiotic division of spermatogenesis?

A

secondary spermatocyte to spermatid

199
Q

when does oogenesis begin? then what happens?

A

birth
suspended until ovulation starts (periods)

200
Q

is cytoplasmic division of oogenesis even or uneven?

A

uneven

201
Q

how long does sperm produciton take?

A

60-65 days

202
Q

how many sperm per ejaculate?

A

100-200 million

203
Q

how many mitotic divisions to form oogonia?

A

30

204
Q

when is meiosis 1 of oogenesis completed?

A

ovulation

205
Q

when do oogonia enter prophase of meiosis 1 by?

A

8th month of intrauterine life

206
Q

when is meiosis 2 of oogenesis complete?

A

fertilisation

207
Q

describe the process of oogenesis

A

oogonia, primary oocyte, secondary oocyte (and polar body), ootid (and 2 more polar bodies), ovum

208
Q

what is the first meiotic division of oogenesis?

A

primary oocyte to secondary oocyte

209
Q

what is the second meiotic division of oogenesis?

A

secondary oocyte to ootid

210
Q

what is a polar body?

A

byproduct of oocyte meiotic division
normally apoptoses

211
Q

name the 2 meiotic pathologies

A

non disjunction
gonadal mosaicism

212
Q

what is non disjunction?

A

failure of chromosomes to separate in m1
failure of chromatids to separate in m2

213
Q

conditions caused by non disjunction

A

trisomy 21 - Downs
monosomy - Turners

214
Q

in which type of conditions is gonadal mosaicism most commonly observed?

A

autosomal dominant
X-linked

215
Q

what is gonadal mosaicism?

A

healthy parent has mutated germ line (in gonads)
increased chance with age
e.g Duchenne’s
parent is healthy but child may have condition

216
Q

define polymorphism

A

non pathogenic variations at a locus from ‘wild type (normal alleles)’

217
Q

what is a wild type?

A

normal allele

218
Q

what is consanguinity?

A

reproductive union of 2 relatives

219
Q

define penetrance

A

proportion of people with a particular genotype that exhibit the phenotype

220
Q

define variable expression

A

some genotypes may be differently expressed and have different phenotypes

221
Q

define genetic anticipation

A

wider trinucleotide repeats of mutated sequence over generations

222
Q

how does genetic anticipation present? give an example of a condition

A

earlier and more severe disease
Huntingtons

223
Q

define late onset

A

manifestation after birth later in life

224
Q

define congenital

A

manifested at birth

225
Q

define autozygosity

A

same mutation from both sides of the family

226
Q

define hemizygous

A

genes carried on an unpaired chromosome
e.g men hemizygous for genes on Y

227
Q

define lyonisation

A

1 female X chromosome of the 2 randomly inactivated

228
Q

define genomic imprinting

A

Epigenetic phenomenon that causes genes to be expressed in a parent-of-origin-specific manner
Prader-Willi Syndrome and Angelman Syndrome both caused by a mutation in the same region of chromosome but are two distinct disorders
PWS - deletion of paternal genes. Absence of active paternal genes - maternal uniparental disomy
Angelman - loss of function of maternal UBE3A due to point mutation or deletion - paternal UPD

229
Q

define sex limitation

A

gene defect affects 1 sex only e.g BRCA-1

230
Q

define allelic heterogeneity

A

different mutations in the same gene can cause the same condition

231
Q

define dominant negative effect

A

a product of a faulty allele affects the healthy allele’s function

232
Q

what is knudson’s two hit hypothesis?

A

2 faulty genes needed to cause cancer

233
Q

features of autosomal dominant disease

A

affects those homozygous and heterozygous
affects males and females equally
affects multiple generations

234
Q

name an autosomal dominant disease

A

Huntington’s

235
Q

features of an autosomal recessive condition

A

only affects those homozygous for the allele
can be a carrier
skips generations
affects males and females equally

236
Q

name an autosomal recessive condition

A

CF

237
Q

features of an X-linked condition

A

no male to male transmission
only female carriers to to male transmission
only men can be affected
females are not affected
men cannot be carriers
(think logically about this one)

238
Q

name 2 X linked conditions

A

Haemophilia
Duchenne’s

239
Q

features of Y linked conditions

A

only males affected
dad to ALL sons

240
Q

hat is the Hardy Weinberg equation?

A

p2+2pq+q2 = 1

241
Q

carrier frequency of CF

A

1/25 (0.04)

242
Q

what is carrier frequency?

A

The proportion of individuals in a population who have a single copy of a specific recessive genetic variant.

243
Q

incidence of CF

A

1/2500

244
Q

what is the genetic defect in CF?

A

delta F508

245
Q

name a non traditional (non Mendelian) disease type

A

mitochondrial
transmission is from a mother to her children
no paternal transmission

246
Q

what is a mutation?

A

spontaneous change in a DNA base sequence

247
Q

what is a deletion?

A

bases removed

248
Q

what is a duplication?

A

base repeated

249
Q

what is an inversion?

A

DNA segment reversed

250
Q

what is translocation?

A

exchange with non-homologous chromosome
equal or non equal

251
Q

what are the two types of substitutions?

A

missense and nonsense

252
Q

what is a missense mutation?

A

change in base causes a new amino acid to be coded for e.g HbA to HbS

253
Q

what is a nonsense mutation?

A

change in base causes premature stop codon formation
UAA, UAG, UGA

254
Q

types of mutation

A

polymorphism - non pathogenic
gene pathogenic - affects gene products (proteins)
chromosomal = whole chromosomes e.g Down’s, Edwards

255
Q

what is a numerical chromosomal mutation?

A

alterations that affect the number of whole chromosomes

256
Q

what is a structural chromosomal mutation?

A

translocations, deletions

257
Q

are males circles or squares on pedigrees?

A

squares

258
Q

how is a dead individual indicated on a pedigree?

A

line through circle or square

259
Q

how are twins indicated on a pedigree?

A

two diagonal vertical lines from the same point
a bridge indicated they are identical

260
Q

what does a diamond indicate on a pedigree?

A

sex unknown

261
Q

how is a stillbirth indicated on a pedigree?

A

diamond with SB

262
Q

how is a termination indicated on a pedigree

A

triangle with a line through it

263
Q

how is a miscarriage indicated on a pedigree

A

triangle

264
Q

how is consanguinity represented on a pedigree?

A

double line

265
Q

what does a karyotype show?

A

normal chromosome configuration

266
Q

what does an ideogram show?

A

distinct banding of chromosomes

267
Q

what type of mutation causes sickle cell anaemia?

A

missense
a new amino acid is coded for
HbA to HbS

268
Q

do the number on the arms go up or down as you approach the centromere?

A

up

269
Q

what number is the centromere?

A

11.1

270
Q

what is the long arm called? what does it go up to?

A

q arm
36.3q

271
Q

what is the short arm called? what does it go up to?

A

petite arm (p)
22.3p

272
Q

what is Turner’s syndrome

A

X monosomy

273
Q

what is the long arm called?

A

q arm

274
Q

what is Down’s syndrome?

A

trisomy 21

275
Q

what is Edward’s syndrome?

A

trisomy 18

276
Q

what is Patau’s?

A

trisomy 13

277
Q

what is Kleinfelter’s?

A

XXY trisomy

278
Q

do the number on the arms go up or down as you approach the centromere?

A

down

279
Q

what is metabolism?

A

all intracellular reactions that take place in the body

280
Q

what is the metabolic rate?

A

rate of intracellular reactions in the body

281
Q

energy content of carbohydrates

A

4 kcal/g

282
Q

energy content of proteins

A

4 kcal/g

283
Q

energy content of alcohol

A

7 kcal/g

284
Q

energy content of fat

A

9 kcal/g

285
Q

how many g of alcohol is one unit?
how many ml of alcohol is one unit?

A

8g alcohol
10ml

286
Q

what is the absorptive state?

A

the fed state
occurs after a meal when your body is digesting the food and absorbing the nutrients (catabolism exceeds anabolism)

287
Q

where is fat stored? name 2

A

adipocytes and Ito cells

288
Q

where are Ito cells found, and what is their function?

A

liver
store fat

289
Q

how is fat stored in adipocytes?

A

triglyceride

290
Q

where are carbohydrates stored? name 2

A

liver
skeletal muscle

291
Q

how are carbohydrates stored?

A

glycogen

292
Q

is protein stored in the body?

A

not really

293
Q

what is the post absorbtive state?

A

the fasting state
occurs when the food has been digested, absorbed, and stored

294
Q

relative levels of insulin and glucagon in the absorptive state

A

high insulin, low glucagon

295
Q

relative levels of insulin and glucagon in the post absorptive state

A

low insulin, high glucagon

296
Q

what is glycogenolysis?

A

glycogen is broken down into glucose for energy

297
Q

effect of insulin on glycogenolysis

A

inhibits glycogenolysis

298
Q

in which order are fats, carbohydrates and proteins used?

A

carbohydrates first, then protein, then fat

Check this one

299
Q

which enzyme converts glucose to glucose 6 phosphate?

A

hexokinase
in the liver, the enzyme is glucokinase

300
Q

which enzyme converts glucose 6 phosphate to fructose-6-phosphate?

A

phosphoglucose isomerase

301
Q

which enzyme converts fructose 6-phosphate to fructose 1,6-bisphosphate?

A

phosphofructokinase-1
PFK-1

302
Q

which is the rate limiting step of glycolysis?

A

fructose-6-phosphate to fructose 1,6-bisphosphate
by PFK-1

303
Q

which two products can fructose 1,6-bisphosphate be converted into?

A

dihydroxyacetone phosphate or glyceraldehyde 3-phosphate (G-3-P)
they are reversible products of each other

304
Q

which enzyme converts fructose 1,6 bisphosphate to its products?

A

aldolase

305
Q

which product of fructose 1,6 bisphosphate is all of the product converted to?

A

G-3-P

306
Q

which enzyme converts dihydroxyacetone phosphate to G-3-P?

A

triose phosphate isomerase

307
Q

which enzyme converts G-3-P to 1-3 bisphosphoglycerate?

A

G-3-P dehydrogenase

308
Q

which enzyme converts 1-3 bisphosphoglycerate to 3-phosphoglycerate?

A

phosphoglycerate kinase

309
Q

which enzyme converts 3-phosphoglycerate to 2-phosphoglycerate?

A

phosphoglycerate mutase

310
Q

which enzyme converts 2-phosphoglycerate to phosphoenolpyruvate?

A

enolase

311
Q

which enzyme converts phosphoenolpyruvate to pyruvate?

A

pyruvate kinase

312
Q

net yield of glycolysis?

A

2 pyruvate
2NADH
2ATP

313
Q

which steps of glycolysis produce ATP?

A

1-3 bisphosphate to 3 phosphoglycerate
and
phosphoenolpyruvate to pyruvate

314
Q

does insulin increase or decrease the rate of glycolysis?

A

increase
affects PFK-1

315
Q

what are the major and minor regulators of glycolysis?

A

minor - hexokinase ativity controlled by G6P
major - PFK-1 allosterically

316
Q

how does glucose 6 phosphate affect hexokinase?

A

inhibits

317
Q

how is PFK-1 affected by AMP?

A

an increase in AMP increases PFK action

318
Q

how is PFK-1 affected by ATP?

A

as ATP increases, PFK activity decreases
inhibited by ATP

319
Q

list the substance in each step of glycolysis

A

good guys feed farm ducks grain, barley 4Ps

glucose
glucose-6-phosphate
fructose-6-phosphate
fructose 1,6-bisphosphate
dihydroxyacetone phosphate
glyceradehyde-3-phosphate
1-3 bisphosphoglycerate
3-phosphoglycerate
2-phosphoglycerate
phosphoenolpyruvate
pyruvate

320
Q

is glycolysis anaerobic or aerobic?

A

anaerobic

321
Q

where does glycolysis take place?

A

cytoplasm

322
Q

products of anaerobic respiration

A

lactate and NAD+, and little ATP
NAD+ allows glycolysis to continue

323
Q

describe the structure of ATP

A

high energy molecule composed of:
adenine
ribose sugar
three phosphate groups
high energy phosphoanhydride bonds between phosphates

324
Q

describe the process of glycolysis

A

Preparative/ energy investment phase
Glucose → glucose-6-phosphate
Requires 1 ATP
Catalysed by hexokinase
Glucose-6-phosphate → fructose-6-phosphate
Catalysed by phosphoglucoisomerase
Fructose-6-phosphate → fructose-1,6-bisphosphate
Requires 1 ATP
Catalysed by phosphofructokinase
Inhibited by ATP, activated by AMP
Fructose-1,6-bisphosphate → 2 x glyceraldehyde-3-phosphate

ATP generating phase
From here on, there are actually 2 reactants and products in total. Ie, one glucose molecule produces 2 pyruvates
Glyceraldehyde-3-phosphate → 1,3-bisphosphoglycerate
2 NADH + 2H+ produced
Triose phosphate dehydrogenase
1,3-bisphosphoglycerate → 3-phosphoglycerate
Produces 2 ATP
Phosphoglycerokinase
3-phosphoglycerate → 2-phosphoglycerate
Phosphoglyceromutase
2-phosphoglycerate → phosphoenolpyruvate
Enolase
Produces water
phosphoenolpyruvate → pyruvate
Creates 2 ATP
pyruvate kinase

325
Q

give the equation for glycolysis

A

Glucose + 2NAD+ + 2Pi + 2 ADP → 2 pyruvate + 2NADH + 2H+ + 2 net ATP + 2H2O

326
Q

function of a kinase enzyme

A

adds/ removes phosphate group

327
Q

function of an isomerase enzyme

A

rearranges structure of substrate without changing molecular formula
similar to mutase

328
Q

function of an aldolase enzyme

A

creates or breaks carbon-carbon bonds

329
Q

function of a dehydrogenase enzyme

A

moves hydride ion to an electron acceptor e.g NAD+

330
Q

function of an enolase enzyme

A

produces a carbon to carbon double bond by removing a hydroxyl group (OH)

331
Q

function of a mutase enzyme

A

moves a functional group in a molecule

332
Q

how is pyruvate converted to acetyl CoA?

A

link reaction in the matrix:
pyruvate (3C) + NAD + CoA → acetyl CoA (2C) + carbon dioxide + NADH

333
Q

why can’t anaerobic respiration continue indefinitely?

A

lactic acid build up is harmful

334
Q

substrates of the TCA cycle

A

can I keep some succinate for my oxaloacetate?
citrate
isocitrate
alpha ketoglutarate
succinyl CoA
succinate
fumarate
malate
oxaloacetate

335
Q

name the enzymes of the TCA cycle

A

citrate and isocitrate keep some substrate for my oxaloacetate!
citrate synthase
aconitase
isocitrate dehydrogenase
alphaketoglutarate dehydrogenase
succinyl CoA synthetase
succinate dehydrogenase
fumarase
malate dehydrogenase

336
Q

draw the TCA cycle

A

ensure all enzymes and byproducts are present

337
Q

name the rate limiting enzymes of the TCA cycle

A

citrate synthase
isocitrate dehydrogenase
a-ketoglutarate dehydrogenase

338
Q

how is citrate synthase inhibited and activated?

A

inhibited:
allosterically by ATP and NADH
competitively by succinyl CoA
activated by ADP

339
Q

which is the main rate limiting enzyme o

A

isocitrate dehydrogenase

340
Q

how is isocitrate dehydrogenase activated or inhibited?

A

Activated by ADP
Inhibited by ATP, NADH

341
Q

how is alphaketoglutarate dehydrogenase activated or inhibited?

A

inhibited by ATP, NADH, succinyl CoA, GTP

342
Q

aim of the Krebs cycle

A

produce NADH and FADH2 for oxidative phosphorylation

343
Q

products of the Krebs cycle per GLUCOSE molecule

A

6 NADH
2 FADH2
2 GTP

344
Q

where else can we obtain acetyl CoA from?

A

beta oxidation of fatty acids

345
Q

where else can we obtain alpha ketoglutarate from?

A

oxidative determination of glutamate
reverse transamination of glutamate and pyruvate

346
Q

describe the process of oxidative phosphorylation

A

NADH to complex 1 of ETC
FADH2 to complex 2 of ETC
they deposit H+ and e- and are oxidised
NAD+ and FADH return to glycolysis and TCA cycle
energy from electron transport chain is used to pump H+ across matrix into inter membrane space
this establishes an electrochemical gradient
electrons are transferred to molecular oxygen, which splits in half and takes up H+ to form water
complex 4 is where oxygen is reduced to water
as H+ flow down their gradient into the matrix, they pass through ATP synthase which synthesises ATP

347
Q

where does TCA cycle occur?

A

mitochondrial matrix

348
Q

where do the ETC and oxidative phosphorylation occur?

A

inner mitochondrial membrane

349
Q

what is the final electron acceptor?

A

oxygen

350
Q

give the equation for the formation of water in the ETC

A

O2 + 4H+ 4e- → 2H2O

351
Q

how many ATP per glucose molecule?

A

30-34

352
Q

what must happen to fatty acids before they can be oxidised in mitochondria

A

activated in the cytoplasm
converted to acyl CoA

353
Q

what process takes acyl CoA with more than 14 carbons through the mitochondrial membrane?

A

carnitine shuttle

354
Q

what is the end product of fatty acid beta oxidation?

A

acetyl CoA

355
Q

what is most of the acetyl CoA generated by fatty acid activation used for?
what is a small proportion used for?

A

TCA cycle
converted into ketones

356
Q

maximum number of carbons that acyl-CoA can have and diffuse through the mitochondrial membrane

A

12

357
Q

explain fatty acid activation, oxidation and utilisation in simple terms
(collectively fatty acid metabolism)

A

activation:
fatty acids converted to acyl adenylate (ATP to ADP) then acyl CoA in the cytoplasm
acyl CoA enters mitochondria by carnitine shuttle

oxidation:
acyl CoA converted to acetyl CoA in mitochondrial matrix

utilisation:
acetyl CoA is used in the TCA cycle or to make ketones

358
Q

where are fatty acids activated?

A

cytoplasm

359
Q

what is the product of activation of fatty acids?

A

acyl CoA

360
Q

how does acyl CoA enter mitochondria if it is large?

A

carnitine shuttle

361
Q

where is acyl CoA converted to acetyl CoA?

A

mitochondrial matrix

362
Q

what is the rate limiting step of beta fatty acid oxidation?

A

carnitine shuttle

363
Q

where else does beta oxidation occur?

A

peroxisomes

364
Q

when does ketogenesis occur?

A

when there is excess acetyl CoA that is not used in TCA cycle

365
Q

when there is an excess, what is acetyl-CoA converted to?

A

acetate, acetoacetate, beta-hydroxybutyrate - ketone bodies

366
Q

what happens to ketone bodies when fuel runs low?

A

converted back into acetyl CoA to enter TCA cycle

367
Q

what is diabetic ketoacidosis?

A

an increase in ketone concentration in blood
high blood glucose
an increase in blood acidity which affects haemoglobin performance in terms of its ability to bind to oxygen

368
Q

what is the brain’s main fuel?

A

glucose, but can adapt to use ketones

369
Q

can the liver use ketones as fuel? why

A

no
does not have the enzyme to convert ketones to Acetyl CoA

370
Q

what is the predominant blood buffering system?

A

bicarbonate buffer system

371
Q

when are fatty acids synthesised?

A

high ATP levels inhibit TCA
build up of acetyl CoA

372
Q

where does fatty acid synthesis occur?

A

cytoplasm

373
Q

can acetyl CoA cross mitochondrial membranes?

A

no

374
Q

what is the range of normal blood pH?

A

7.35-7.45 pH

375
Q

equation for blood buffer

A

CO2 + H2O ⇄ H2CO3 ⇄ HCO3- + H+

376
Q

function of carbonic anhydrase

A

convert carbon dioxide and water to carbonic acid

377
Q

fate of carbonic acid

A

dissociates into hydrogencarbonate ions and protons

378
Q

which two substance form the buffer? which is the acid, and which is the base?

A

carbonic acid (acid) and hydrogen carbonate ions (base)

379
Q

w are CO2, protons and HCO3- regulated?

A

CO2 is regulated by breathing
protons and HCO3- are renally regulated

380
Q

general henderson hasselbach equation

A

pH = pKₐ + log10([A⁻]/[HA])

381
Q

henderson hasselbach equation for the carbonic acid/ bicarbonate system

A

pH = 6.1 + log10([HCO3⁻]/0.03[CO2])
or
pH = 6.1 + log10(25mM/0.03[40mmHg])

0.03 is a proportionality constant for CO2 which converts the partial pressure in mmHg into a concentration in solution which in turn equates into a H2CO3 concentration

382
Q

how is the efficiency of bicarbonate as a buffer improved?

A

carbon dioxide is removed at the lungs
bicarbonate is regenerated at the kidneys

383
Q

functions of haemoglobin

A

oxygen transport
carbon dioxide transport to lungs (carbaminohaemoglobin)
mops up excess H+ as a buffer
NO transport around body for vasodilation

384
Q

equation for oxygen transport using haemoglobin

A

Hb + O2 ⇄ HbO2

385
Q

equation for carbon dioxide transport using haemoglobin

A

Hb + CO2 ⇄ HbCO2

386
Q

equation for hydrogen reacting with haemoglobin

A

Hb + H+ ⇄ HbH

387
Q

what is acidosis?

A

pH is lower than 7.35

388
Q

what is alkalosis?

A

pH is greater than 7.45

389
Q

what is response to acidosis or alkalosis called?

A

compensation

390
Q

what are two types of acidosis and alkalosis?

A

respiratory and metabolic

391
Q

what is an ABG?

A

arterial blood gas measurement

392
Q

definition of metabolic acidosis

A

low pH
low HCO3-
ROME - respiratory, opposite, metabolic, equal

393
Q

compensation for metabolic acidosis

A

deep hyperventilation to decrease arterial pCO2

394
Q

definition of metabolic alkalosis

A

high pH and high HCO3-

395
Q

compensation of metabolic alkalosis

A

hypoventilation and renal HCO3- excretion to increase arterial pCO2

396
Q

definition of respiratory acidosis

A

low pH
high carbon dioxide

397
Q

compensation for respiratory acidosis

A

increase in renal HCO3- retention

398
Q

definition of respiratory alkalosis

A

high pH
low CO2

399
Q

compensation for respiratory alkalosis

A

increase in excretion of HCO3-

400
Q

what is the anion gap?

A

anions - cations
([Na+] + [K+])-([Cl-] - [HCO3-])

401
Q

normal range of values for anion gap

A

4-12mmol/L

402
Q

what are reactive oxygen species?

A

highly reactive oxygen containing compounds that are free radicals

403
Q

is hydrogen peroxide a radical?

A

no, but can be decomposed in chains of reactions

404
Q

name two reactions in which hydrogen peroxide is decomposed

A

Fenton
Heber-Weiss

405
Q

name protections from ROS

A

cellular components
antioxidant vitamins e.g E,C

406
Q

what are ROS key in?

A

respiratory burst
immunological defence mechanism
phagocytes release ROS to hydrolyse foreign material

407
Q

name conditions associated with high ROS levels

A

diabetes
Parkinsons
renal failure

408
Q

difference between mitosis and meiosis

A

meiosis
- only in gametes
- recombination of genetic material for diversity
- two cell divisions
- 4 haploid daughter cells

409
Q

how long will body glycogen levels last?

A

12 hours

Phase 1 flashcards (27 decks)

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