Cell Biology

Front 1

What are the three cell types with regard to cell cycle

Back 1

Permanent, Stable, Labile

Front 2

Cell cycle: Permanent cells

Back 2

Remain in G0. If they regenerate, they regenerate from stem cells.

Front 3

Cell cycle: Stable cells

Back 3

Enter G1 from G0 when stimulated

Front 4

Cell cycle: Labile cells

Back 4

Never go to G0, divide rapidly with a short G1

Front 5

Permanent cells: cell types

Back 5

-Neurons
-Skeletal and cardiac muscle
-RBCs (regenerate from stem cells)

Front 6

Stable cells: cell types

Back 6

-Hepatocytes
-Lymphocytes

Front 7

Labile cells: cell types

Back 7

-Bone marrow
-Gut epithelium
-Skin
-Hair follicles
(think about chemotherapy side effects)

Front 8

Rough Endoplasmic Reticulum: Functions

Back 8

-Synthesis of secretory (exported) proteins
-N-linked oligosaccharide addition to many proteins

Front 9

Rough Endoplasmic Reticulum,rich cells:

Back 9

-Mucus-secreting goblet cells of small intestine
-Antibody-secreting plasma cells
(ie lost of secretory protein)

Front 10

Neurons: name of Rough Endoplasmic Reticulum and its function

Back 10

Nissl bodies sytnhesize enzymes (eg ChAT) and peptide neurotransmitters.

Front 11

Smooth Endoplasmic Reticulum: Functions

Back 11

-Steroid synthesis
-Detoxification of drugs and poisons

Front 12

Smooth Endoplasmic Reticulum rich cells

Back 12

-Liver hepatocytes
-Steroid hormone-producing cells of the adrenal cortex

Front 13

6 functions of Golgi apparatus?

Back 13

1. Distribution center
--Input: Proteins and lipids from endoplasmic reticulum
--Output: Plasma membrane, lysosomes, secretory vesicles
2. Modifies N-oligosaccharides on asparagine
3. Adds O-oligosaccharides to serine and threonine residues (on protein)
4. Addition of mannose-6-phosphate to proteins designated for lysosome
5. Proteoglycan assembly from core proteins
6. Sulfation of sugars in proteoglycans and of selected tyrosine on proteins

Front 14

I-cell disease: Problem

Back 14

In Golgi apparatus, failure to add mannose-6-phosphate to intralysosomal designated proteins leads to their improper export

Front 15

I-cell disease: Presentation

Back 15

-coarse facial features
-clouded corneas
-restricted joint movement
-high plasma levels of lysosomal enzymes
-fatal in childhood

Front 16

3 types of vesicular trafficking proteins

Back 16

COPI, COPII, and Clathrin

Front 17

COPI: Function

Back 17

Retrograde Intracellular transport: cis-Golgi to RER

Front 18

COPII: Function

Back 18

Anterograde Intracellular transport: RER to cis-Golgi

Front 19

Clathrin: Function

Back 19

Extracellular/lysosomal transport:
-lysosome: trans-Golgi to lysosome
-trans-Golgi to plasma membrane to endosomes (for receptor mediated endocytosis)

Front 20

Microtubules: Diameter

Back 20

Diameter 24 nm

Front 21

Microtubules: Structure

Back 21

13 dimers of alpha/beta tubulin per circumference (each dimer bound to GTP), repeated in helical configuration

Front 22

Microtubules: Location?

Back 22

-Flagella
-Cilia
-Mitotic spindles

Front 23

Microtubules: Functions?

Back 23

- It gives rigidity and structure to cell
-It permits movement within cell
-It is involved in slow neuronal axoplasmic transport

Front 24

Microtubules: Speed of growth and collapse

Back 24

Grows slowly and collapses quickly

Front 25

Microtubules: Affected by which drugs?

Back 25

-Mebendazole/thiabendazole (antihelminthic)
-Taxol (anti-breast cancer)
-Griseofulvin (anti-fungal)
-Vincristine/Vinblastine (anti-cancer)
-Colchicine (anti-gout)

Front 26

Microtubule polymerization defects: Found in what syndrome

Back 26

Chediak-Higashi syndrome

Front 27

Chediak-Higashi syndrome
Cause and effect?

Back 27

Microtubule polymerization defect resulting in decreased phagocytosis

Front 28

Cilia: Structure

Back 28

-9+2 arrangement of microtubule doublets
-The 9 peripheral doublets are linked by dynein atpase

Front 29

Cilia: Mechanism

Back 29

The 9 peripheral doublets are linked by dynein atpase, which causes bending of cilium by differential sliding of doublets

Front 30

Molecular motors and direction of transport in cell?

Back 30

-Dynein: retrograde (DIES back towards nucleus)
-Kinesin: anterograde (MOVES kinetically forward)

Front 31

Kartagener's syndrome, cause?

Back 31

Dynein arm defect causing immotile cilia

Front 32

Kartagener's syndrome: Presentation

Back 32

-Male infertility (immotile sperm)
-Female infertility (immotile fallopian cilia)
-Bronchiectasis and recurrent sinusitis (bacteria and particles not pushed out)
-Situs inversus

Front 33

What syndrome is situs inversus associated with?

Back 33

Kartagener's

Front 34

Plasma membrane: composition

Back 34

-Cholesterol (~50%)
-Phospholipids (~50%)
-Sphingolipids
-Glycolipids
-Proteins

Front 35

Plasma membrane: melting temperature association

Back 35

High cholesterol or long saturated fatty acid content means increased melting temperature

Front 36

Nucleus, Function?

Back 36

-DNA replication and transcription into RNA

Front 37

Nucleus, components?

Back 37

- Enzymes for replication and repair of newly synthesized DNA
-Enzymes for transcription and processing of RNA precursors
-Nuclear envelope
-Nuclear lamina
-Nucleolus
-Chromatin

Front 38

Nuclear envelope,structure?

Back 38

Double membrane (inner and outer membrane)
Pore of 90 nm in diameter

Front 39

What is the outer nuclear membrane continuous with?

Back 39

ER

Front 40

Nuclear lamina,structure

Back 40

- Lamins and proteins

Front 41

Function of lamins

Back 41

-Attach chromatin to inner memb of nuclear envelope
- Participate in breakdown and reformation of nuclear envelope during cell cycle

Front 42

What permits reformation of nuclear envelope during cell cycle

Back 42

Lamins

Front 43

What permits nuclear disassembly into small vesicles and when?

Back 43

-Phosphorilation of the lamina by Lamin kinase
-Prophase of mitosis

Front 44

Nucleolus, function?

Back 44

-Synthesis of rRNA
-Ribosome assembly

Front 45

Nucleolus, Structure?

Back 45

-Granular zone:contains ribosomal precursor particles
-Fibrillar zone:contains ribonuclear protein fibrils
-Fibrillar center:containsDNA not being transcribed.

Front 46

Chromatin:structure?

Back 46

-DNA
-Histone proteins
-non-histone proteins

Front 47

Chromatin:DNA structure and function?

Back 47

-Double stranded helical molecule
-3 conformations: B,Z and A
-Carries genetic info of cell

Front 48

Chromatin:Histone proteins structure and function?

Back 48

-(+)charged proteins eith lysine and arginine residues.
-Forms 2 structures:Nucleosomes (10 nm)and solenoid fibers (30 nm)

Front 49

Chromatin:
Histone proteins:
-Nucleosome function

Back 49

Nucleosomes are the basic repeating units of the chromatin fiber, having a 10 nm diameter.

Front 50

Chromatin:nonhistone proteins structure and function?

Back 50

-Acidic or neutral proteins.
-Enzymes involved in nuclear functions: replication and transcription,DNA repair and regulation of chromatin function

Front 51

Chromatin, forms?

Back 51

-Heterochromatin
-Euchromatin

Front 52

Chromatin,heterochromatin:
structure & characteristic, % of chromatin,association with barr body?

Back 52

-Highly condensed (30 nm of solenoid fibers)and transcriptionally inactive.
-10 % of total chromatin
-Almost entire inactive x chromo or barr body in somatic cells in women is condensed into heterochromatin

Front 53

Chromatin, euchromatin:s tructure & characteristic, % of chromatin % transcribed?

Back 53

-Extended form of DNA and transcriptionally active.
-90 % of total chromatin
-Only 10% transcribed in the 10 nm fiber of nucleosomes

Front 54

Cytoplasm: components?

Back 54

-Ribosomes
-RER
-SER
-Golgi
-Lysosomes
-Peroxisomes
-Mitochondria
-Cytoskeleton

Front 55

Cytoplasm,
Ribosomes:
structure

Back 55

-rRNA and proteins
-2 units: Large (60S) and small (40S)

Front 56

Cytoplasm,
Ribosomes:
Site of synthesis.

Back 56

-Synthesized in nucleus and transported to cytoplasm through pores:
-Large units in nucleolus , small subunits in nucleus.

Front 57

Cytoplasm,
Ribosomes:
Polysomes:definition,movement of ribosomes and binding with subunits.

Back 57

-Ribosomes that are formed of mRNA being translated by several ribosomes at the same time.
-5'---3'with small units binding first.

Front 58

Cytoplasm,
Ribosomes:
Forms, functions

Back 58

-Free ribosomes: site of synthesis for proteins--> nucleus,peroxisomes and mitochondria
-Membrane-associated polysomes: site of synthesis of secretory proteins,memb proteins and lysosomal enzymes.

Front 59

Cytoplasm,
RER:
-Structure

Back 59

stacks of large sacs called cisternae studded with ribosomes on the cytoplasmic side.

Front 60

Cytoplasm,
SER:
-Structure

Back 60

-Sacs,vesicles and tubules continuous with RER, without ribosomes.
-Enzymes involved in biosynthesis of Phospholip,sterols and TG.

Front 61

Cytoplasm:
SER,functions:

Back 61

-Detoxification reax
-Glycogen degradation and gluconeogenesis
-Reax in lipid metabolism
-Sequestration and Release of Calcium ions

Front 62

Cytoplasm:
SER,Detox reax:

Back 62

-Reax that make compounds water soluble so they can be excreted
-Hydroxylation reax: with hydroxylases complexes containing cytochrome P450,a flavaprotein, and a nonheme iron protein.
-Conjugation reax: transfer of polar groups from the active carrier to the toxic water-insoluble molecule.

Front 63

Cytoplasm:
SER,glycogen degradation and gluconeogenesis:
definition and function?

Back 63

Removal of P from glu-6-P by the enzyme glu 6 phosphatase,integral memb protein of the SER.
-Control of the formation of free glucose from glycogen and via gluconeogenesis.

Front 64

Cytoplasm:
SER,Lipid metabolism:

Back 64

Lipolysis begins in SER with release of FA from TG.
Assembly of lipoprotein particles

Front 65

Cytoplasm:
SER,name in striated muscle and sequestration of ions.

Back 65

-SER=SR or sarcoplasmic reticulum
-Ca ions.

Front 66

Cytoplasm:
GOLGI,structure?

Back 66

- disc-shaped smooth cisternae assembled and associated with membrane-bound vesicles
- 2 faces: cis or forming face associated with RER
Trans or maturing face or TGN oriented towards cytoplasm

Front 67

Golgi-related disease:
Hyperproinsulinemia:
Characteristics and clinical manifestations?

Back 67

- Elevated levels of proinsulin in the serum due to failure of peptidase to cleave proinsulin and C-peptide in the Golgi aparatus.
-Clx :is equal to those seen in pts with noninsulin dependent diabetes.

Front 68

Cytoplasm:
Lysosomes,structure

Back 68

-Spherical membrane enclosed organellesthat contain enzymes required for intracellular digestion.
-2 forms:
Primary: with no materilas to digest particles
Secondary: formed by fusion of primary lysosomes, enzymes present and partially digested materials.

Front 69

Cytoplasm:
Lysosome,Enzymes names and characteristics?

Back 69

A.60 hydrolytic enzymes:-Nucleases: degrades DNA and RNA
-Lipases: for lipids
-Glycosidases for glycoconjugates
-Proteases and peptidases for proteins.
-Phosphatases
B. Characteristics:
-Acid hydrolases
-optimal activity at 5.0 pH
-Synthesis occurs in RER, transfer to golgi where modified and packaged into lysosomes.

Front 70

Lysosomal related disease:
I-cell disease or mucolipidosis II, cause & enzyme role?

Back 70

-Deficiency of N-acetylglucosamine-phosphorotransferase.
-Enzyme responsable of phosphorilation of mannose in glycoproteins which targets proteins to lysosomes. (in addition to N-acetylglucosaminidases)

Front 71

Lysosomal related disease:
I-cell disease, effects of enzyme deficiency?

Back 71

-Enzymes sent to the wrong destination.
-Huge inclusion bodies in cells due to accumulation of undergraded glycoconjugates in lysosomes.
-Missing enzymes found in plasma and other body fluids where they keep up with degradation activity.

Front 72

Lysosomal related disease:
I-cell disease, name and characteristics in adults?

Back 72

-Pseudo-Hurler polydistrophy:
-less severe
-Later onset
-Potential survivor rate.

Front 73

Lysosomal related disease:
I-cell disease, Tx and Prenatal Dx?

Back 73

-No tx
-Prenatal Dx available.

Front 74

Cytoplasm:
Peroxisomes,Structure and role of enzymes?

Back 74

- Small spherical membrane-bound organelles
-Enzymes that transfer H from organic substrates to molecular O2--> Hydrogen peroxide.
-Ex:Catalase: degrades H peroxide to water and O2

Front 75

Cytoplasm:
Peroxisomes, enzymess synthesis and incorporation?

Back 75

-free polysomes
-Incorporated into peroxisomes after translation

Front 76

Cytoplasm:
Peroxisomes,functions?

Back 76

- Syntheis and degradation of hydrogen peroxide
-B-oxidation of long FA chains (> 24)
(Starts inperoxisomes and continues until reaches 10 carbons --> oxidation in mitochondria)
-Phospholipid exchange
-Bile acid synthesis.

Front 77

Peroxisome related disease,
Names,physiopathology

Back 77

-Zwelleger (cerebrohepatorenal syndrome, Neonatal adrenoleukodystrophy, Infantile Refsum disease, Hyperpipecolatemia.
- Pts fail to oxidize very long chains of FA and accumulate bile acid precursors.

Front 78

Cytoplasm,
Mitochondria: structure?

Back 78

-Outer membrane.
-Inner membrane.
-Intermembrane compartment
-Matrix

Front 79

Cytoplasm,
Mitochondria: characteristics of membranes?

Back 79

-Outer membrane: smooth, highly permeable with porins,proteins and chanels.
-Inner membrane: impermeable to most small ions like Na,K,and H and small molecules like ATP,ADP and pyruvate.
Contains infoldings or cristae that contain enzymes for ETC and Oxidative phosphorylation.

Front 80

Cytoplasm,
Mitochondria: function of intermembrane compartment?

Back 80

Intermembrane compartment: enzymes that use ATP to phosphorylate other nucleotides (creatine phosphokinase,adenylate kinase)

Front 81

Cytoplasm,
Mitochondria: matrix location,components

Back 81

It's in the inner membrane and it contains:
-Dehydrogenases
-dsDNA genome
-RNA,proteins and ribosomes
-intramitochondrial granules.

Front 82

Cytoplasm,
Mitochondria: characteristics and functions of dehydrogenases.

Back 82

They oxidize substrates of the cell (pyruvate,AA,FA)--> reduced NADH and reduced FADH2 for use by ETC and energy generation

Front 83

Cytoplasm,
Mitochondria: characteristics and functions of dsDNA.

Back 83

-Encodes a few of the mitochondrial proteins
-Inherited from mother
-leads to maternal transmision of diseases of energy metabolism.

Front 84

Cytoplasm,
Mitochondria: Site of synthesis of mitochondrial proteins.

Back 84

- Most mitochondrial proteins are synthesized in the cytoplasm and transferred into mitochondria.

Front 85

Cytoplasm,
Mitochondria: components and functions of intramitochondrial granules.

Back 85

-Calcium and magnesium
-Storage site for calcium.

Front 86

Cytoplasm,
Cytoskeleton:components?

Back 86

-Microtubules
-Intermediate filaments
-Microfilaments

Front 87

Cytoplasm,
Cytoskeleton:
Microtubules main component

Back 87

tubulin

Front 88

Cytoplasm,
Cytoskeleton:
Tubulin structure, characteristics and blockers.

Back 88

- protein dimer composed of alpha and beta tubulin
-Polymerization of tubulin form microtubules in center and they're surrounded by tau proteins and microtubule-associated proteins.
-Ca2+ block or reverse polymerization.

Front 89

Cytoplasm,
Cytoskeleton:
Microtubules associated disease.

Back 89

Chediak-Higashi syndrome

Front 90

Chediak-higashi syndrome:characteristics,defects.

Back 90

-Characterized by a defect in microtubule polymerization.
-Defects in cytoplasmic granules:
a)delayed fusion phagosomes with lysosomes in wbc--> preventing phagocytosis of bacterias;
b)Increased fusion of melanosomes in melanocytes--> albinism;
c) Granular defects in NK cells and platelets.

Front 91

Cytoplasm,
Cytoskeleton:
Microtubules associated drug.

Back 91

Actin-binding drugs: CYTOCHALASIN B

Front 92

Actin-binding drugs: CYTOCHALASIN B, pharmacodynamis and pharmacokinetics

Back 92

-Interfere with polymerization-depolymerization cycle of microfilaments.
-Inhibits endocytosis, phagocytosis,cytokinesis and cytoplasmic and amoeboid movements.

Front 93

Cytoplasm,
cytoskeleton:
Intermediate filaments structure,functions and location of proteins.

Back 93

- Intermediate in thicknessbetween microtubules and microfilaments (10nm)
-Structural roles:
a)cytokeratin: in epithelial tissue
b)Desmin:smooth muscle,Z disks and skeletal and cardiac muscle.
c)Vimentin: cells of mesenchymal origin (endothelial cells, fibroblasts,chondroblasts,
vascular smooth muscle)
d)Neurofilaments: in neurons
e)Glial acidic proteins GFA found in astrocytes.

Front 94

Cytoplasm,
Cytoskeleton:
Microfilaments's structure and type of movements?

Back 94

- Composed of F-actin and G-actin
- Two types of movement:
1.Local movement (e.g., endocytosis, phagocytosis, cytokinesis, and, amoeboid movement)--inhibited by cytochalasin B
2.Sliding filament movement--actin in almost every cell.

Front 95

Cytoplasm,
Cytoskeleton:What is the drug that acts on microfilaments?

Back 95

Actin-binding drugs:
Cytochalasin B which interferes with polymerization-depolymer cycle of microfilaments thus inhibiting local movements.

Front 96

What are the components of Cell surface?

Back 96

1. Basement Membrane
2. Lateral Surface specializations:
a. Tight Junction (Zonula Occludens)
b. Zonula Adherens
c. Desmosomes (Macula adherens)
3. Gap Junctions (Anexus)
4. Apical (Free) Surface Specializations
a.Microvilli
b.Cilia

Front 97

Cell surface,
Basement membrane appearance and composition?

Back 97

- Sheet-like structure underlying all epithelia
- Composed of:
a.Basal lamina--composed of type IV collagen, proteoglycans (heparin sulfate), glycoproteins (laminin)
b.Reticular lamina--composed of delicate reticular fibers.

Front 98

Cell surface,
Names of Lateral Surface Specializations?

Back 98

a. Tight Junction (Zonula Occludens)
b. Zonula Adherens
c. Desmosomes (Macula adherens)

Front 99

Cell surface,
Names of Lateral Surface Specializations:
Tight Junction's location,constitution,functionand appearance on micrograph?

Back 99

- Located near luminal surface of epithelium (will see cilia)
- Formed by fusion of opposed cell membranes
- Constitutes the anatomic component of many barriers in the body: blood-testes barrier.
- Shows sealing strands on freeze-fracture micrograph

Front 100

Cell surface,
Names of Lateral Surface Specializations:
Zonula Adherens's location and function?

Back 100

- Lies basal to zonula occludens
- Band-like junction that serves in attachment of adjacent epithelial cells.

Front 101

Names of Lateral Surface Specializations:
Desmosomes's constitution, postion,function and main characteristic?

Back 101

- Formed by juxtaposition of two disc shaped plaques contained within the cytoplasm of each adjacent cell.
- Intermediate filaments (tonofilaments) radiate away from the plaque
- Desmosomes--most common, hold cells together and is important in epithelial stress.
- Only intracellular junction with electron density on each side of membrane.

Front 102

What is the Only intracellular junction with electron density on each side of membrane?

Back 102

Desmosomes

Front 103

Names of Lateral Surface Specializations:What is a demidesmosomes and where is it found?

Back 103

Hemidesmosome: found in basal membrane and underlines basal lamina. It anchors cells to underline basal membrane.

Front 104

Cell surface,
Gap Junctions (Anexus):
What is it, function, subunits, function of conenexons, tissues in which they are well-developed?

Back 104

- Area of communication between adjacent cells
- Allows passage of very small particles and ions
- Hexagonal lattice of tubular protein subunits called connexons
- Connexons create hydrophilic channels connecting the cytoplasm of adjacent cells and permit the direct passage of ions and small molecules between cells to conduct electrical impulses A.k.a. "communicating junctions".
- Well-developed in tissues where cells are electrically coupled (e.g., cardiac and smooth muscle)

Front 105

What are " communicating junctions"?

Back 105

Connexons

Front 106

Cell surface,
Gap Junctions (Anexus):
The difference between gap junctions and tight junctions?

Back 106

=Gap junctions are longer and never at luminal surface compared to tight junctions

Front 107

Cell surface,
Name of apical (Free) Surface Specializations?

Back 107

-Microvilli
-Cilia

Front 108

Cell surface,
Name of apical (Free) Surface Specializations:
Microvilli definition,structure and function?

Back 108

- Apical cell surface evaginations
- Thick glycocalyx coat
- Contain actin microfilaments
- Increase surface area of cells for absorption.
- Anchored in apical cell cytoplasm to terminal web which is anchored to zonula adherens of cell membrane

Front 109

Cell surface,
Apical (Free) Surface Specializations:
Microvilli, what is a stereocilia?

Back 109

Stereocilia is elongated microvili located in small intestine, epididymis, ductus deferens and hair cells of inner ear for auditory sensation.

Front 110

Cell surface,
Apical (Free) Surface Specializations:
Cilia's definition, position,structure,location and function?

Back 110

- Apical cell surface projections of the cell membrane that contain microtubules (internal array of microtubule pairs)
- Inserted on centriole-like basal bodies present below the membrane surface
- Contain two central microtubules surrounded by a circle of nine peripheral microtubule doublets
9 + 2 arrangements of microtubules (9 doublets of microtubules)
- Dynein is an ATP ase that links (nexin links) peripheral 9 doublets and causes bending of cilium.
-Located in lower respiratory epithelium like traquea, never in esophagus.
- Functions:
a.motility: Cilia move back and forth to propel fluid and particles in one direction. Important in clearing mucus from the respiratory tract.
b.Retrograde axon transport by dynein

Front 111

Cell surface,
Apical (Free) Surface Specializations:
Cilia: action of Dynein is an ATP ase?

Back 111

Dynein is an ATP ase that links (nexin links) peripheral 9 doublets and causes bending of cilium by differential sliding of doublets in retrograde.
- Movement results from interaction of dynein arms with B subtubules
- Pair of dynein arms attached to each A subtubule arms bind to ATP adjacent doublets slide

Front 112

Cell surface,
Apical (Free) Surface Specializations:
Cilia: what are flagellas?

Back 112

Flagella are longer than cilia but with the same microstructure. It is found sperm.

Front 113

What is Kartagener's Syndrome?

Back 113

Immobile cilia syndrome:
Immotile cilia and flagella due to dynein arm defect. Results in male and female infertility (sperm immotile), bronchioectasis and recurrent sinusitis (bacteria and particles not pushed out); associated with situs inversus.