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Robert Hooke

1660, cork, named cells

1

Anthony con Leeuwenhoek

First to look at bacteria, sperm, muscles and used his 70-250x mi scope

2

Cell theory by

Schleiden and Schwann 1839

3

Cell theory

Unit, dual existence, arise from pre existing cells

4

6 features of cells

Duplicate via cell cycle, RNA info intermediate, translation occurs, proteins formed, plasma membrane

5

Cells in the human body

10^14

6

Classification based on morphology

5 kingdoms- plantae, fungi, animalia, Protista and prokaryotes

7

Classification based on rRNA

3 domains- bacteria, archaea and eukaryotes

8

Prokaryotic cells

No nucleus, very small, circular DNA, 70s ribosome.
No compartments

9

Eukaryotic cells

Nucleolus, larger, linear DNA, 80s ribosome, organelles

10

Typical cell size

1-50 micrometers

11

First cell developed

3-4 million years ago

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First eukaryotic cells

2 billion years ago

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Central dogma

DNA -> RNA -> Protein

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RNA world hypothesis as the origin of life as it

Carrots information and can fold into catalytic ally active enzymes

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Ribozyme

Enzymatic ally active RNA molecule

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Class I RNA ligase

Polymerises ribonucleotides

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Reactive ribonucleotides

Building blocks of RNA formed under early earth conditions and can spontaneously polymerise on clay surfaces

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Replicase ribozymes

Started metabolism by producing new replicases.

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Fatty acids at the start formed from

Hydrogen and carbon monoxide

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Polar fatty acids self organise into

Micelles

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Head of fatty acid

Hydrophilic

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Tail of fat acid

Hydrophobic

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Vesicles form from micelles in...

In an acidic pH or triggered by a clay surface

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Protocell

Formed as RNA replicase and vesicles combine

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Scanning electron microscopy

Scans surface of dead sample

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Transmission electron microscopy

Goes through thin dead sample

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Optical resolution limit

Minimum distance that allows recognition of object details

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Light microscopy

200nm limit, living cells

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Electron microscopy

0.05 nm limit, dead cells

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Fluorescence

Emission of light by a substance that has absorbed light

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GFP

Green fluorescent protein

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FRAP

Fluorescent recovery after photo bleaching
Mobility of proteins

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FLIP

Fluorescent loss in photobleaching

34

Amphipatic

Has both hydrophobic and hydrophilic regions

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Cholesterol in males forms

Testosterone

36

Cholesterol in females forms

Estradiol

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Sphingolipid

Fatty acid with attached Sphingo sugar

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3 main ion channel types

Voltage gated, mechanically gated, ligand-gated

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GEF

Guanine nucleotide exchange factor

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GAP

GTPase-activating protein

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G proteins are

Molecular switches

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Rab-GTPase

Membrane trafficking

43

Kinase A activated by

cAMP produced by adenylyl cyclase

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Dephosphorylation

Removing a phosphate

45

Phosphorylation

Adding a phosphate

46

Kinase

Phosphorylation enzyme

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Phosphatase

Dephosphorylation enzyme

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Percent of human proteins with a phosphate group

30%

49

No of kinases in human genome

520

50

No of protein phosphatases in human genome

150

51

Kinase adds the phosphate to

A serine side chain

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Cdk kinase activation

Add 1 Pi
Remove 1 Pi
Cyclin present

53

Src kinase

Add 1 Pi
Remove 1 Pi
Interrupted binding occurred

54

Amount of protein in cytoplasm

300 mg/ml

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Svedberg unit (S)

Measure of the sedimentation rate of a particle

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Eukaryotic ribosome

80s

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Prokaryotic ribosome

70s

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Nuclear pore

8 fold symmetry with 20 nucleoporins

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Poly some

Número use ribosomes along a single mRNA molecule

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Nucleus

2-10 um, 10% of cell volume

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Nuclear Lamina

Filamentous network of proteins on the inside of the nuclear envelope

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During mitosis the nuclear Lamins are

Phosphorylated

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Nucleolus

Inside the nucleus where ribosomes are formed

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Granular component of the nucleolus

Where ribosomes assemble

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Fibrillation centre of the nucleolus

Where rRNA transcription occurs

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Chromatin

DNA with associated proteins

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Euchromatin

Transcriptionally active DNA

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Heterochromatin

Transcriptionally inactive DNA

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Nucleosome

DNA wrapped around his tones

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30nm DNA fiber

DNA, histones and histone 1

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Histones

H2A, H2B, H3, H4

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300nm DNA fiber

Further packaged DNA around scaffold proteins forming metaphase chromosomes

73

Transcription

The process of transcribing DNA nucleotide sequence information. Into RNA sequence information

74

RNA polymerases in eukaryotes

RNA polymerase I, II and III

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RNA polymerase I

rRNA

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RNA polymerase II

mRNA

77

RNA polymerase III

tRNA

78

Plant RNA polymerase

RNA polymerase IV for siRNA

79

Purines

Adenine and guanine

80

Pyrimidines

Thymine and cytosine

81

Instead of thymine RNA uses

Uracil

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Lissencephaly

Defect in nuclear migration due to gene lis1

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Eukaryotic transcription and translation

Occur in different compartments and many genes on one mRNA

84

Prokaryotic transcription and translation

One gene per mRNA, both occur in cytoplasm

85

Endomembrane system components

Nucleus, ER, Golgi, lysosomes, endosomes and transport vesicles

86

Exocytosis

Intra cellular vesicle fuses with membrane to move things out of the cell

87

Endocytosis

Opposite of exocytosis where the cell takes things up

88

3 trafficking pathways

Biosynthetic secretory, endocytosis, retrieval recycling

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Biosynthetic secretory

ER -> Golgi-> exterior or lysosomes

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Endocytic pathway

Cell exterior to lysosomes

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Retrieval recycling pathway

From endsome/vesicle to exterior or Golgi then ER

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ER

Synthesis and transport organelle that is an extension of the nuclear envelope

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Functions of the ER

Calcium storage, lipid synthesis, processing of proteins

94

Co translational translation occurs

On the RER. Ribosome binds mRNA from the nucleus and then travels due to a signal sequence out of the nucleus to the ER

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ER protein signal sequence

5-10 aa on the n terminus

96

Type I and II and III integral membrane protein

Hydrophobic middle with a amino and a hydroxyl group on either end of he protein

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Type IV integral membrane protein

Multiple hydrophobic regions

98

Golgi

Processing and sorting membrane stack formed of cisternae

99

Cis face of goli

Entry

100

Trans face of Golgi

Exit

101

Proteins arrive at the Golgi containing a

N-linked oligosaccharide

102

Cis Golgi network

Phosphorylated the oligosaccharide

103

Cis cisterna

Removes mannose

104

Medial cisterna

Removes mannose and adds GLcNAc

105

Trans cisterna

Adds galactose
Adds NANA

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Trans Golgi network

Sulfation of tyrosine and carbohydrates

107

Oligosaccharides can be linked to proteins either by

N linkage or o linkage

108

N linkage bonds via

Nitrogen to asparagine

109

O linkage bonds to

Oxygen via threonine

110

3 types of endosomes

Early, late, recycling

111

Early endsome ph

4.5

112

Late endosome ph

4.5

113

Recycling endosome ph

6.8

114

Lysosome

Acidic organelle with a ph of 4.5 used in degradation and containing acidic hydrolases and lipases

115

Phagocytosis

Endocytosis of large particles

116

Pinocytosis

Endocytosis of liquid

117

Receptor mediated endocytosis

Uses a ligand and receptor complex to take up membranes

118

Autophagy

Enclosure of cytosol and organelles in an autophagosome for degradation

119

Peroxisomes

Organelle important for lipid metabolism and detoxification

120

Hydrogen peroxide fro the peroxisomes is broken down by

Catalase

121

Peroxisomes of plants

Glyoxysomes

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Lipid droplets

Monolayer vesicle containing fatty acids and cholesterol

123

FABP

Fatty acid binding proteins

124

Snare proteins

Provide membrane specificity and increase fidelity

125

V-snare

Vesicle snare

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t-snare

Target snare (on target membrane)

127

Snare stands for

Soluble NSF attachment protein receptor

128

Binding proteins for vesicles

On vesicle- v snare and rab-GTP
On target- t snare and rab-binding tethering protein

129

Fusion of vesicle and target steps

Tethering, docking, fusion

130

Vesicle coating proteins

Cathrin, copI and copII

131

Clathrin

Endocytosis vesicles

132

COPI

Golgi vesicles

133

COPII

ER to Golgi vesicles

134

Filamentous bio-polymers

Microtubules, F actin and intermediate filaments

135

Microtubule size

25nm

136

F-actin size

7-9nm

137

Intermediate filament size

10nm

138

Architecture that shapes the cell

Tensegrity architecture

139

Globular actin monomer

G actin

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Protofilament of actin

String of polymerised g actin

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Poly filament of actin

F actin- 2 protofilaments of g actin in a helix

142

3 types of actin bundling

Ordered, dynamic, cross linking

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Ordered actin bundling

Microvilli on epithelial cells

144

Stress fibres

Contractile bundles formed from f-actin and myosinII

145

Lamelipod

Leading edge of the cell where actin is found w

146

Microtubule monomer

Tubulin dimers

147

Tubulin formed from

Alpha tubulin and beta tubulin with 2 GTP

148

Microtubulus are formed at the

Centrosome in MTOCs

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MTOC

Microtubulus organising centre

150

Microtubulus

13 protofilaments in a stable tube

151

Microtubulus stabilised by a

GTP-tubulin cap

152

EB1

Stabilised microtubules

153

GTP-tubulin plus water

GDP-tubulin and a phosphate

154

Transition where microtubules becomes unstable

Catastrophe

155

Transition where microtubules becomes stable

Rescue event

156

Dynamic instability

The constant switching between growth and shrinkage in microtubules

157

MAP

Microtubules associated proteins (stabilise the tracks)

158

PCM

Peri-centricular material

159

Gamma tubulin

Nucleates microtubules

160

Centrosome contains

Centrioles and PCM

161

Centrioles made of

Mother centrioles, daughter centriole and a flexible linker

162

Intermediate filaments

Found only in animal cells and form the nuclear Lamina

163

Example of intermediate filaments

Keratin and vimentin

164

Intermediate fibre structure

Self assemble (not ATP) and consist of protein subunits with coiled coil proteins in a domain structure

165

Domain structure of intermediate filaments

Coiled coil with globular proteins either end (2 alpha helixes)

166

Beta keratin forms

Nails, scales and feathers

167

Alpha keratin forms

Hair and horns

168

Eyes made of

7 intermediate filaments but mainly vimentin

169

Molecular motors are

Mechano-enzymes

170

Molecular motor structure

Dimer of heavy chains with associated light chains joined by a coiled coil

171

Motor domain

Heavy chain where ATP is hydrolased

172

Motors on microtubules

Kinesin and dynein

173

Motors on actin

Myosin

174

Direction of myosin movement

Minus to plus

175

Direction of kinesin movement

Minus to plus

176

Direction of dynein movement

Plus to minus

177

Myosin II

Muscle myosin

178

Myosin V

Membrane trafficking

179

Phosphoinositides

Membrane components with a lipid anchor and an inositol ring