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Histo > Cytology > Flashcards

Cytology Flashcards

1
Q

What is a Feulgen stain for? Color?

A

Nuclei (specifically DNA) stains red

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2
Q

What is a H&E stain for?

A

Nuclei (DNA), nucleoli (RNA), and basophilic structures (RNA in rER & ribosomes) stain blue
Cytoplasm and acidophilic structures (cytoplasmic proteins) stain pink

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3
Q

What is a hematoxylin stain for? Color?

A

Stains DNA (nuclei), RNA (nucleoli), and basophilic structures (ribosomes, rER) blue

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4
Q

What is an eosin stain for? Color?

A

Stains the cytoplasm and acidophilic structures (cytoplasmic proteins) pink

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5
Q

What is a Periodic-Acid Shift (PAS) stain for? Color?

A

Stains carbohydrates and carbohydrate-rich molecules red

Glycogen, starch, cellulose, mucin, collagen, cartilage-matrix, thyroid colloid

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6
Q

What is a Silver Impregnation for?

A

Stains Golgi, reticulum, nerve fibers, and cell borders of the mesothelium

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7
Q

What does Osmium Tetroxide stain?

A

Stains Golgi, myelin, and lipids

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8
Q

What does Methyl Green stain?

A

DNA stains green

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9
Q

What does Pyronin stain?

A

RNA stains red

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10
Q

What does Phosphotungstic Acid Hematoxylin (PTAH) stain? Color?

A

Stains mitochondria, nuclei, and contractile elements of striated muscle blue/purple

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11
Q

What is an artefact?

A

A flaw on a slide caused by a faulty technique

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12
Q

What can be used as a “ruler” when viewing cells with a light microscope?

A

RBCs are approximately 7-8 um

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13
Q

What are possible causes for an artefact?

A
  1. Postmortem degradation
  2. Shrinkage
  3. Precipitation
  4. Wrinkles & folds
  5. Nicks
  6. Technician handling
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14
Q

Four common features of cells

A
  1. Surrounded by membrane
  2. Have nuclei (zero for RBCs)
  3. Contain organelles (membrane or non-membrane bound)
  4. Contain inclusions (nonliving material)
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15
Q

Functions of the nucleus

A
  1. DNA replication (for cell division)
  2. DNA repair
  3. RNA transcription and processing
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16
Q

What are the three major components of the nucleus?

A

Nuclear envelope, chromatin, and nucleolus

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17
Q

Why is the evaluation of the morphology of the nucleus important?

A

Helps determine the health of the cell

Ex: tumor cell development

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18
Q

What are the key features of the nuclear envelope?

A

Has two unit membranes (outer and inner) 10-30 nm apart that are separated by the perinuclear cisternae and are continous with one another at the nuclear pores
Has lamin proteins near inner membrane

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19
Q

What is the perinuclear cisternae?

A

Space between the two unit membranes of the nuclear envelope (10-30 nm)

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20
Q

What is the difference between the inner and outer membranes of the nuclear envelope?

A

Inner membrane faces nuclear matrix, associates with the chromatin and is supported by the nuclear lamina
Outer membrane faces the cytoplasm, is continuous with (shares biochemical/functional properties) rER, can have ribosomes attached

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21
Q

Functions of the nuclear pores

A

Act as bidirectional gates between cytoplasm and nucleus
Allows small molecules to pass via diffusion (8-9 nm)
All proteins with a nuclear localization amino acid sequence are transported via active transport

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22
Q

What is the nuclear localization AA sequence?

A

The amino acid sequence that allows proteins to pass through the nuclear pores via active transport

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23
Q

Small proteins can pass through the nuclear pores via facilitated diffusion. T/F

A

False, proteins of all size need a nuclear localization AA sequence to pass via active transport

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24
Q

Structure of the nuclear pore

A

Two octagonal rings (cytoplasmic and nuclear) made from 8 nucleoporin (nuclear pore proteins) subunits each that form central pore (70-80 nm)
Protein filaments extend from both rings, but form basket on nuclear side (allow reactions to occur)

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25
Q

If you were able to inject a dye into the perinuclear cisternae where could that dye be found if it were free to move in the cisterna?

A

Lumen of the rER (because outer leaflet is continuous with rER, dye could move into that region)

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26
Q

Why do we call the boundary of the nucleus a nuclear envelope instead of a nuclear membrane?

A

The nucleus is surrounded by two unit membranes separated by a perinuclear cisterna (space). Therefore it is called a nuclear envelope.

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27
Q

What structures associated with the nuclear envelope can be seen with the electron microscope?

A
  • Inner nuclear membrane
  • Outer nuclear membrane with associated ribosomes
  • Perinuclear cisternae
  • Nuclear pores
  • Nuclear lamina
  • Continuity of the outer nuclear membrane with the rER
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28
Q

Functions of the nuclear lamina

A
  • Gives shape/stability to nuclear envelope
  • Links chromatin and nuclear envelope
  • Holds pores in nuclear envelope
  • Dissolves/reforms nuclear envelope during cell division (via phosphorylation)
  • Organizes the interphase nucleus
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29
Q

Location and structure of nuclear lamina

A

Between inner nuclear membrane and heterochromatin, made lamins A, B, C (intermediate filament proteins)

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30
Q

What does phosphorylation of the nuclear lamins cause?

A

Dissolves nuclear lamina during mitosis/cell division

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31
Q

What are envelopathies and laminopathies?

A

Mutations in the proteins of the nuclear membrane or lamins

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32
Q

Chromatin

A

Complex made of DNA, histone and non-histone proteins in the nucleus of eukaryotic cells

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33
Q

Heterochromatin

A

Condensed DNA of genes that are not being transcribed, can be constitutive (never transcribed) or facultative (transcription depends on cell type)

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34
Q

What does heterochromatin look like in a light microscope?

A

Appears as basophilic clumps

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35
Q

Euchromatin

A

Uncoiled / loosely packed DNA of genes that are being transcribed
Aka extended chromatin

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36
Q

Nucleosome

A

Looks like nucleosome beads on a DNA string, is the simplest arrangement of chromatin packing in the nucleus (11 nm wide)
DNA makes 1.75 turns around 8 proteins (four histone types in pairs, called nucleosome) connected by linker DNA

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37
Q

30 nm chromatin fibrils

A

Nucleosomes coil into threads/fibrils due to different histone types binding together

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38
Q

300 and 700 nm chromatin fibers

A

The coiled 30 nm fibrils are looped into 300 nm loops, which are further coiled into 700 nm helical loops (chromosomes of metaphase)

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39
Q

What packaging structure is seen with a light microscope in mitotic/meiotic cells during metaphase?

A

700 nm chromatin fibers of condensed chromosomes

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40
Q

What is the order and size of the packing structures of DNA in the nucleus?

A 
Helical DNA (2 nm)
Nucleosome (11 nm)
30 nm chromatin fibrils
Chromatin fibers (300 and 700 nm loops)
Chromosomes (1400 nm)
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41
Q

Genotype

A

of chromosomes in somatic cells, species specific (humans = 46)

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42
Q

Karyotype

A

Standard map of the banding pattern of each chromosome during metaphase stage

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43
Q

Autosomes

A

Chromosomes that are not sex chromosomes (humans = 22)

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44
Q

Sex chromosomes

A

One pair per cell

XX or XY

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45
Q

Barr body

A

The inactive X chromosome of females
Seen as drumstick
or heterochromatin clump next to nuclear envelope in light microscope, more obvious in WBCs

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46
Q

Chromatid

A

One copy of a chromosome formed by DNA replication still joined at the centromere to the other copy

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47
Q

Diploid

A

Cells with full complement of chromosomes (humans = 46)

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48
Q

Haploid

A

Having only one of each pair, like germ cells (23)

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49
Q

Polyploid

A

Having more than one complement of chromosomes

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50
Q

Aneuploidy

A

Any deviation in the normal number of chromosomes

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51
Q

What are examples of aneuploidy?

A

Trisomy - 3rd chromosome of one type (Down’s syndrome, Klinefelter’s syndrome)
Monosomy - absence of chromsome in pair (Turner’s syndrome XO)

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52
Q

Nucleolus

A

Eccentric, not surrounded by membrane, 1-2 per cell (depends on species/activity of cell)
Site of rRNA transcription, has nucleolar organizing region

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53
Q

Location of the nucleolus

A

Eccentric circle of condensed DNA not surrounded by membrane

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54
Q

How many nucleoli are found in cells?

A

1-2 depending on species and activity of cell

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55
Q

Function of the nucleolus

A

Site of rRNA transcription primarily

Also regulates the cell cycle with nucleostemin (protein contained in nucleolus that stops G1

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56
Q

Nucleolar Organizing Region (nuclear associated chromatin)

A

10 expanded chromosomes (pairs of 5) that contain genes that encode rRNA, also helps to reorganize the nucleoli after cell division
The DNA transcription loops of the NOR chromosomes form circle that is the nucleolus

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57
Q

Composition of the nucleolus

A

Lots of rRNA and protein (basophilic)

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58
Q

Areas of the nucleolus

A
  • Fibrillar center - stains pale
  • Pars fibrosa - dense fibrillar region
  • Pars granulosa - granular compartment
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59
Q

Structure of the ribosome

A

Large subunit - 60S, catalyzes peptide bond formation, made of 28S, 5S, and 5.8S rRNA
Small subunit - 40S, binds mRNA and tRNA in cytoplasm, recruits large subunit, made of 18S

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60
Q

Formation of ribosomes

A

In nucleolus: Nucleolar organizing DNA is transcribed to form pre-rRNA, which associates with ribosomal proteins (forms ribonucleoproteins), pre-rRNA is cleaved into 28S, 18S, and 5.8S rRNAs

In nucleus: 28S and 5.8S combine with 5S rRNA (transcribed in nucleus) to form large ribosomal subunit, then ribosomal subunits are actively transported through nuclear pores into cytoplasm

In cytoplasm: Ribosomal subunits assemble into ribosomes/polysomes with mRNA

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61
Q

Translation of mRNA into proteins by ribosomes takes place in nucleus. T/F

A

False, translation takes place in the cytoplasm

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62
Q

Ribosomal subunits are transported out of the nucleus with simple diffusion. T/F

A

False, nuclear pores use active transport to move proteins in and out of the nucleus

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63
Q

All rRNA are transcribed in the nucleolus. T/F

A

False, the 5S rRNA is transcribed in the nucleus and assembles into the large subunit in nucleus

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64
Q

What events of the formation of ribosomes takes place in the nucleolus?

A

Transcription of pre-rRNAs, association of pre-rRNAs with ribosomal proteins, and cleavage of rRNAs into 28S, 18S, and 5.8S

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65
Q

What events of the formation of ribosomes takes place in the nucleus?

A

Assembly of the 5S, 28S, and 5.8S rRNA into the large ribosomal subunit and active transport of ribosomal subunits out of the nucleus through nuclear pores

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66
Q

What events of the formation of ribosomes takes place in the cytoplasm?

A

Assembly of the ribosomal subunits into the ribosome / polysomes in association with mRNA

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67
Q

Four key concepts of membranes

A
  1. They are not homogenous
  2. Membrane components are in constant dynamic flux
  3. Membranes are asymmetric (outer and inner leaflet totally different)
  4. The shape of the surface membrane is partly determined by the underlying cytoskeleton
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68
Q

What nuclear components can be seen with the light microscope?

A

Nuclear envelope, heterochromatin, and nucleolus

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69
Q

Structure of the unit membrane

A

Trilaminar structure (3 distinct layers) when viewed with EM (outer and inner leaflet electron dense)

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70
Q

What substance is responsible for half of the mass of membranes?

A

Lipids

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71
Q

What is the function of lipids in the membrane?

A

Responsible for membrane form and permeability

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72
Q

What is the most abundant type of lipid in the membrane?

A

Phospholipids

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73
Q

What is the second most abundant type of lipid in the membrane?

A

Cholesterol

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74
Q

What is the function of cholesterol in membranes?

A

Maintains the structural integrity

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75
Q

What is the third most abundant type of lipid in membranes?

A

Glycolipids

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76
Q

Where are glycolipids always found in membranes?

A

Outer leaflet

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77
Q

Order the three most common lipids found in membranes from most abundant to least abundant

A

Phospholipids > cholesterol > glycolipids

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78
Q

What is the function of proteins in membranes?

A

Give the membrane its specific functions

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79
Q

What type of molecules are permeable to the unit membrane? What type aren’t?

A

Small hydrophobic (oxygen, CO2, nitrogen, and benzene) and small, uncharged, polar molecules (water, urea, glycerol) are permeable

Large, uncharged, polar molecules (glucose, sucrose) and ions (H+, HCO3-) are not permeable

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80
Q

How is the presence of membrane proteins indicated?

A

Using the freeze fracture technique

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81
Q

What are common specific functions of membrane proteins? (6)

A

Enzymes, channels, receptors, cell-cell recognition, intercellular junctions, bind to cytoskeleton/ECM

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82
Q

Where are carbohydrates located on the unit membrane?

A

Outer leaflet

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83
Q

What does the carbohydrate component of the membrane contribute to?

A

Glycocalyx

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84
Q

What is the function of the glycocalyx?

A

Cell recognition

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85
Q

What is the structure of the glycocalyx?

A

Made of glycolipids and glycoproteins coated in carbohydrates

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86
Q

Lipid raft

A

Floats in plasma membrane and groups proteins that need to interact together
Has a specialized membrane domain (longer phospholipid tails, so only proteins with long transmembrane domains can enter)

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87
Q

Cytoskeleton

A

Dynamic network of protein filaments that organizes cytoplasm and gives cell shape
Made of microfilaments, intermediate filaments, and microtubules

88
Q

Functions of the cytoskeleton

A
  • cell motility
  • organelle and vesicle transport
  • muscle contraction
  • cell division
  • endocytosis/phagocytosis
  • provides mechanical strength
89
Q

Order the components of the cytoskeleton from smallest to largest

A

Microfilament (7 nm) < intermediate filament (10 nm) < microtubule (25 nm)

90
Q

What is the major cytoskeletal protein of most cells?

A

Actin

5-10% of total cell protein

91
Q

What is the diameter of microfilaments?

A

7 nm

92
Q

What are microfilaments composed of?

A

Actin

93
Q

Protein found on the outer and inner leaflets of unit membranes are the same. T/F

A

False, the protein are very different since each side faces a different compartment of the body and thus has different reactions/functions

94
Q

Which side of the cell membrane is similar to the inner leaflet of a organelle membrane?

A

The outer leaflet, since molecules outside of the cell are brought in and out of the organelle and need to interact

95
Q

Which side of the cell membrane is similar to the outer leaflet of a organelle membrane?

A

The inner leaflet, since both are facing the cytoplasm

96
Q

Structure of a microfilament (mf)

A

Polar G-actin proteins bind head to tail to form polar protofilaments
Two protofilaments twist into helix to form F-actin filaments
The F-actin filaments have a positive (barbed) and negative (pointed) end
Can branch

97
Q

Protoplasm

A

Individual masses of cells containing nucleic acids, proteins, lipids, carbohydrates, salts

98
Q

Inclusions

A

Cell constituents that may or may not be membrane bound

Of end product nature (produced by organelles)

99
Q

The plasmalemma is an organelle. T/F

A

True, the cell membrane is an organelle

100
Q

What type of appearance does the cell membrane show in an EM?

A

Trilaminar appearance when cells have been treated with osmium tetroxide

101
Q

How are peripheral proteins bound to the cell membrane?

A

Ionic interactions

102
Q

Where are bound carbohydrates typically located?

A

Bound to membrane proteins and polar head groups of lipids typically on EC surface

103
Q

What is the collective term for the coating of carbohydrates on the plasma membrane?

A

Glycocalyx

104
Q

Actin filaments can branch. T/F

A

True

105
Q

Function of a microfilament (mf)

A
  • Cell-cell and cell-matrix adhesion
  • Cell shape
  • Stability and function of microvilli
  • locomotion/contraction
  • Endo/exocytosis
106
Q

Functions of actin-binding proteins

A
  • Branching (Arp 2/Arp3)
  • Regulate filament dynamics (filament growth)
  • Organize filaments into 2-D networks (bundling proteins) or 3-D gels (gel-forming proteins)
  • Actin-motor proteins use ATP to move to plus end
107
Q

Treadmilling

A

Microfilament based movement where actin is added to one end while taking away actin on the other

108
Q

Intermediate filaments

A

Provides mechanical strength to cells that are subject to stress
Made up of a variety of proteins that are specific for the cell type

109
Q

The ___ domain of intermediate filaments is similar while the ___ are different and allows different interactions to occur.

A

Alpha-helical rod, amino and carboxy terminals

110
Q

___ are the most stable cytoskeletal component.

A

Intermediate filaments

111
Q

Structure of intermediate filament

A

Has similar alpha-helical rods with different amino and carboxy terminals
Wound into coiled coil like rope, then staggered to make tetramer (basic subunit of IFs)

112
Q

Microtubules (MTs)

A

Polar, hollow cylinders of 13 parallel protofilaments composed of dimers of alpha and beta tubulin subunits
Plus end grows rapidly, minus end is embedded in MTOC

113
Q

Both microfilaments and microtubules are branching. T/F

A

False, only MFs are branching

114
Q

Centrosome

A

An MTOC composed of a pair of centrioles at right angle with 50 gamma-tubulin rings acting as template for MT growth

115
Q

Centriole structure

A

Composed of nine triplets of MT

116
Q

Functions of microtubules

A
  • Cell shape
  • Organelle transport
  • Chromosome separation during mitosis/meiosis
  • Ciliary/flagellar movement
117
Q

Many functions of microtubules are due to the property of ___.

A

Dynamic instability

118
Q

Dynamic instability

A

The rapid conversion between growing and shrinking of microtubules
Beta-tubulin subunit is enzyme that catalyzes hydrolysis of GTP into GDP, destabilizing the MT
GTP means its growing, GDP means its shrinking

119
Q

Microtubule-Associated Proteins (MAPs)

A

Bind to MTs, organize MTs in bundles, stabilize MTs from disassembly, mediate interactions with other cellular components, organize cytoplasm functionally, increase rate of nucleation, act as molecular motors

120
Q

Microtubule motor proteins

A

Some MAPs use ATP to move in a single direction along the filament

121
Q

Kinesin

A

MT motor protein directed towards plus end

122
Q

Dynein

A

MT motor protein directed towards minus end

123
Q

Kinesin is directed towards the ___ end of MTs while Dynein is directed towards the ___ end.

A

plus, minus

124
Q

The cell cycle consists of ___ and ___.

A

Interphase, mitosis

125
Q

Interphase is composed of what four aspects?

A

G1 Phase, G0, S phase, and G2

126
Q

G1 Phase

A

Cell growth, cell monitors its environment and size

127
Q

G0

A

Resting state, near end of G1

128
Q

S Phase

A

Replication of DNA, duplication of centrioles

129
Q

G2 Phase

A

Safety gap, cell makes sure DNA replication is complete

130
Q

Prophase

A
  • Chromatin starts to condense
  • Disassembly of cytoplasmic MTs
  • Beginning of mitotic spindle formation
131
Q

Prometaphase

A
  • Nuclear envelope breaks down

- Chromosomes attach to spindle

132
Q

Metaphase

A

-Chromosomes align on metaphase plate

133
Q

Anaphase

A
  • Kinetochores separate

- Movement of chromatids to opposite poles

134
Q

Telophase

A
  • Separated chromatids arrive at poles
  • Kinetochore MTs disappear
  • Polar MTs elongate
  • Nuclear envelope reforms
  • Chromosomes decondense
135
Q

Cytokinesis

A

Cytoplasmic division

136
Q

The replication of the centrioles occurs during the ___.

A

S Phase of interphase

137
Q

During ___, MTs origininating from the centrosome increase.

A

Prophase

138
Q

When do cellular MTs increase their rate of disassembly?

A

Late prophase

139
Q

Structure of mitotic spindle

A

Polar MTs overlap at midline of spindle, push poles apart
Kinetochore MTs attach to kinetochore at centromere
Astral MTs radiate in all directions from centrosome to position poles in cell and help separate the poles

140
Q

What three MTs are part of the mitotic spindle?

A

Astral MTs, kinetochore MTs, and polar MTs

141
Q

How does cytokinesis take place?

A

A ring of actin and myosin filaments contracts to split cell

142
Q

For dynamic instability, ___ means the MT is growing, while ___ means the MT is shrinking.

A

GTP, GDP

143
Q

Annulate lamellae

A

Stacks of parallel lamellae (cisternae) with many pores (like nuclear envelope)
Occur in rapidly dividing cells (germ cells)

144
Q

Endoplasmic reticulum

A

Largest membraneous system in cell consisting of interconnected tubules and vesicles
Two interconnected components: rER and sER

145
Q

Smooth endoplasmic reticulum

A
  • Prominent in cells that specialize lipid metabolism (hepatocytes) and steroid synthesis (leydig)
  • Synthesizes cholesterol and fatty acids and lipids
  • Have enzymes for detox of lipid soluble drugs
  • Sequesters calcium in cytosol (SR in skeletal m)
146
Q

Which organelle is prominent in alcoholics or drug addicts?

A

sER

147
Q

Rough endoplasmic reticulum

A
  • Membrane contains ribosomes on cytoplasmic side
  • Prominent in protein secreting cells (ergastoplasm)
  • Adds post-translation modifications to newly synthesized protein destined for secretion, lysosomes, and plasma membrane (for stability)
148
Q

Which organelle is prominent in cells that specialize in lipid metabolism and steroid synthesis?

A

sER

149
Q

Which organelles is prominent in protein secreting cells?

A

rER, Golgi apparatus

150
Q

Ribosomes are directed to the rER membrane by the ___ on the growing polypeptide chain.

A

Signal peptide

151
Q

Golgi Apparatus

A

Functions in protein packaging, concentration, and sorting
Has functional polarity: convex (cis) surface receives secretory proteins from rER and concave (trans) side is where vesicles exit

152
Q

Golgi apparatus compartments

A
  1. cis face
  2. medial
  3. trans face
  4. trans Golgi network (TGN)
153
Q

Trans Golgi network (TGN)

A

Where sorting of proteins occurs (lysosomes, plasma membrane, and constitutive [continuous] or regulated secretion)

154
Q

What are the 3 types of coated vesicles?

A

Clathrin-coated, coatomer-coated, and caveolae

155
Q

Functions of clathrin-coated vesicles

A

Transport of newly synthesized proteins from TGN to lysosomes, granules for regulated secretion, and formation of vesicles in receptor-mediated endocytosis

156
Q

Morphology of clathrin-coated vesicles

A

Clathrin triskelion (3-legged structure made of 3 large and 3 small polypeptide chains), associates to form polyhedral cage network around vesicle

157
Q

Receptor-mediated endocytosis

A

Receptor coated pits containing clathrin invaginate to form clathrin-coated vesicles
Vesicles lose clathrin coat and fuse/mature into an endosome

158
Q

Coatomer-coated vesicles

A

Covered with coatomer proteins I or II that transport to/away from Golgi
COP I - retrograde transport: from Golgi to rER (donating membrane back to ER)
COP II - anterograde transport: rER to Golgi

159
Q

___ donates membrane back to the endoplasmic reticulum.

A

COP I

160
Q

___ transport material to and from the Golgi.

A

Coatomer-coated vesicles

161
Q

Caveolae

A
  • Form due to lipid composition of membranes
  • Made of caveolin
  • Function in clathrin-independent endocytosis and transcytosis
  • In walls of blood vessels and in smooth muscle, help to concentrate calcium
162
Q

Pinocytosis

A

Ingestion of fluids and solutes via small
vesicles
Includes receptor-mediated endocytosis

163
Q

Endosomes

A

Vesicles associated with endocytosis

164
Q

What are the 2 types of endocytosis?

A

Pinocytosis and phagocytosis

165
Q

Pinocytosis is a clathrin-dependent form of endocytosis. T/F

A

False, pinocytosis can be clathrin-independent (involves caveolin-coated vesicles) or clathrin-dependent (receptor-mediated endocytosis)

166
Q

Receptor-mediated endocytosis is a clathrin-dependent form of pinocytosis. T/F

A

True

167
Q

Phagocytosis

A

Ingestion of large particles in phagosomes, performed by specialized cells mostly from monocytes

168
Q

Phagosomes

A

Vesicles formed by phagocytosis, fuse with lysosomes to degrade phagocytized particles

169
Q

Phagocytosis process

A

Phagocytes have receptors (Fc receptors) that recognize the surface of the foreign substance and ingest it by zippering the membrane around it

170
Q

Lysosomes

A

Contain acid hydrolases (enzymes) with internal pH of 4.7 (maintained by proton pump), degrades endocytosed material and cellular material

171
Q

Lysosomal acid hydrolases are synthesized in the ___ and targeted to the lysosomal compartment with the addition of ___ to the lysosomal protein in the ___.

A

rER, mannose-6-phosphate (M6P), trans Golgi network (TGN)

172
Q

COP I transports from ___ to ___, while COP II transports from ___ to ___.

A

Golgi, rER

rER, Golgi

173
Q

Exocytosis

A

Fusion of vesicles with plasma membrane

174
Q

What are the two secretory pathways leading to exocytosis?

A

Constitutive pathway and regulated secretory pathway

175
Q

Constitutive secretion

A

Continuous, unregulated delivery to membrane (collagen)

176
Q

Regulated secretion

A

In specialized cells, stored near membrane, needs a signal for release, calcium dependent

177
Q

Mitochondria can be visualized with a light microscope. T/F

A

True

178
Q

Mitochondria components

A
  1. Outer membrane
    - -porins and receptors
  2. Intermembrane space
    - -like cytoplasm, has kinases and cytochrome c
  3. inner membrane
    - -cristae, ATP synthases, cardiolipin, cellular respiration enzymes, and special transport proteins
  4. Matrix space
    - -Matrix granules (bind cations), Krebs cycle enzymes, beta-oxidation enzymes, DNA, tRNA, ribosomes
179
Q

The ___ of the mitochondria has the highest protein concentration than any membrane of the cell.

A

Inner membrane

180
Q

The thin folds of inner membrane that project into the interior of the mitochondria are called ___.

A

Cristae

181
Q

Cardiolipin

A

Phospholipoprotein that makes the inner membrane impermeable to ions

182
Q

Mitochondrial production of ATP

A

Reactions of the matrix space

  • -conversion of pyruvate and fatty acids into acetyl CoA
  • -acetyl CoA enters the Krebs cycle and NADH and FADH2 are produced

Reactions on the inner membrane

  • -electrons from NADH and FADH2 are passed down the respiratory or electron transport chain causing protons (H+) to be pumped across the membrane from the matrix into the intermembrane space generating an electrochemical proton gradient across the inner membrane
  • -the gradient drives protons back through the ATP synthase complex causing ATP synthase to add a phosphate to ADP forming ATP
183
Q

Mitochondria has their own DNA, ribosomes, tRNA, and mRNA. T/F

A

True

184
Q

Mitochondria have ___ in the matrix space that bind cations and regulate / localize ion concentrations.

A

Matrix granules

185
Q

Mitochondrial apoptosis

A

Release cytochrome c from the intermembrane space into the cytoplasm which activates proteolytic enzymes in the caspase cascade

186
Q

In ___, mitochondria are used to produce heat.

A

Brown fat cells

187
Q

Peroxisomes

A
  • -Beta oxidation of fatty acids into acetyl CoA
  • -Contain oxidative enzymes that produce H2O2
  • -Catalase converts H2O2 into water and oxygen
  • -detox in liver and kidney cells (in sER)
  • -Needed for myelin formation
188
Q

What differentiates organelles and inclusions?

A

Inclusions are generally inactive

189
Q

Glycogen morphology

A

PAS stain

EM - rosettes (glycogen granules covered by enzyme layer)

190
Q

Glycogen location

A

All cells, but commonly liver and muscle

191
Q

Lipid morphology

A

Light microscope - round, clear vacuoles

If fixed with osmium tetroxide - black sphere

EM - surrounded by mitochondria

192
Q

Lipid location

A

Adipocytes abundant in liver and steroid secreting cells

193
Q

Lipofuscin

A

Left over yellow-brown pigment from lysosomes

194
Q

Lipofuscin location

A

In cells with long life span, nerve and cardiac muscle

195
Q

The age pigment refers to ___.

A

Lipofuscin

196
Q

Hemosiderin

A

Byproduct of hemoglobin

197
Q

Hemosiderin location

A

In macrophages of spleen, bone marrow, and liver where old RBCs are degraded

198
Q

Melanin

A

Inserted over top of nucleus, protects nuclei from UV radiation
Found in keratinocytes, pigment cells of retina, and some nerve cells of brain

199
Q

Crystals

A

Precipitation found in steroid producing cells

Leydig cells and Sertoli cells of testis

200
Q

The least common form of inclusion is ___.

A

Crystals

201
Q

Necrosis

A

Due to injury or disease processes, associated with inflammation and tissue deterioration
Cell swells, chromatin clump, organelles fuse, cell lyzes, macrophage phagocytizes

202
Q

Apoptosis

A

Programmed cell death
Cell volume decreases, organelles remain intact and move to blebs in membrane, cell breaks into membrane bound globules that are phagocytized

203
Q

Cell death: ___ occurs to single cells while ___ occurs to groups of neighboring cells.

A

Apoptosis, necrosis

204
Q

In apoptosis, the cell size ___ while in necrosis the cell ___.

A

Decreases, swells

205
Q

Only apoptosis has blebs in cell membrane, not necrosis. T/F

A

False, blebbing occurs in necrosis as well, but the organelles don’t localize in the blebs to break up into membrane-bound globules

206
Q

The mechanism of apoptosis utilizes caspases in both extrinsic and intrinsic pathways. T/F

A

True

207
Q

Procaspase activation and caspase cascade

A

Signal (intracellular or extracellular) activates a procaspase, which activates other procaspases leading to amplification of active caspases, which digest key proteins leading to cell death

208
Q

___ cause the caspase cascade in the extrinsic pathway of activation of apoptosis.

A

Lymphocytes

209
Q

___ causes the caspase cascade in the intrinsic pathway of activation of apoptosis.

A

Cytochrome c

210
Q

The caspase cascade is caused by cytochrome c in the ___ pathway of activation of apoptosis, while lymphocytes causes it in the ___ pathway.

A

Intrinsic, extrinsic

211
Q

Biological processes where apoptosis play an essential role

A 
Development: 
--correct # and spacing of neurons
--middle ear space
--vaginal opening
--webs of fingers/toes
--correct cell #
Adults
--mammary glands and uterus before/after pregnancy 
--uterus during menstrual cycle
--elimination of viral/transformed cells
--changes in liver after drug use
--size of organs after trauma
212
Q

Ergastroplasm

A

Area of cytoplasm that is stained basophilic in protein secreting cells for the RNA-rich ribosomes
High concentration of rER

213
Q

Zymogen granules

A

Pink stain (H&E) of secretory granules of enzymes located near lumen

214
Q

What is the function of early endosomes?

A

Sorting of ligand-receptors of endocytosis

215
Q

Early endosomes

A

A non-lysosomal compartment that maintains an acidic environment in which ligands are dissociated from receptors

Histo (10 decks)

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