Exam 2 Flashcards

Question

Spontaneous DNA damage

Answer 1

- Depurination - Deamination If unrepaired when DNA is replicated, these changes lead to either a deletion or a base pair substitution in the daughter strand

Answer 2

Loss of a purine base via hydrolysis of the N-glycosyl linkage

Answer 3

The amino group of a purine or pyrimidine base is hydrolyzed such that adenine is converted to hypoxanthine, guanine is converted to xanthine, and cytosine is converted to uracil, which forms an unnatural deoxyuride - A -> I - G -> X - C -> U

Answer 4

Ie. UV radiation, produces covalent linkage between two adjacent pyrimidines known as pyrimidine dimers (T-T or C-T) - pyrimidine cyclobutane dimers - 6-4 covalent linkage of pyrimidines

Answer 5

Ie X-rays, reactive oxygen species produced cause direct strand breaks, DNA-protein cross-links, and 40-60 chemically distinct base damages

Answer 6

- pyrimidine cyclobutane dimers - 6-4 covalent linkage of 2 pyrimidines Caused by nonionzing radiation

Answer 7

Agents insert between stacked bases of the DNA double helix, causing some unwinding of the helix and separation of base pairs - they are mutagenic and interfere with replication, repair processes, and transcription, and can also interfere with topoisomerase and cause strand breaks (Ie. Ethidium bromide, thalidomide, doxorubicin, daunomycin)

Answer 8

Can cause damage to DNA

Answer 9

Pyrimidine dimers O6-methylguanine Enzymes: DNA photolyase and methylguanine transferase

Answer 10

Single base mismatches, nondistorting alterations Enzymes: DNA glycolases, AP endonuclease, AP lyase, DNA polymerase, DNA ligase

Answer 11

Chemical adducts that distort DNA (pyrimidine dimers, BPDE-guanine adducts, cisplatin adducts) Enzymes: NER protein complex, DNA polymerase, DNA ligase

Answer 12

Associated disorder of nucleotide excision repair Inherited disease where Skin is extremely sensitive to sunlight, causing pt to be prone to melanoma and squamous cell carcinoma UV light causes cyclobutane thymine dimers to form in DNA which is easily repaired by NER, but those with defects in XP proteins in the NER complex exhibit the disease

Answer 13

Mismatched base in daughter strand Enzyme: MER complex, helicase/endonuclease, DNA polymerase, DNA ligase

Answer 14

Associated disorder of Mismatch excision repair Inherited disease with mutation of one of the alleles of genes in the MER complex results in increased susceptibility to HNC cancer Mutation in both alleles would render the MER system nonfunctional and allow tumor development

Answer 15

Double-strand breaks, interstrand cross-linking

Answer 16

double-strand breaks, interstrand cross-linking - damaged ends filled in and joined; some base pairs may be missing. Multiple proteins and enzymes including DNA ligase

Answer 17

Double-strand breaks, interstrand cross-linking - Exonucleases, DNA polymerase, MER system, Damaged duplex repair using information on undamaged homologous duplex

Answer 18

Associated disorder of recombination repair: homologous recombination BRCA 1 and 2 are tumor supressor genes. Mutations cause a fivefold increase in a woman's chance of having breast and/or ovarian cancer before reaching menopause. Men with mutations also have an increased chance of developing breast cancer. Mutations in these genes also lead to increased risk of developing other cancers

Answer 19

Stalled RNA polymerase during transcription (not replication)

Answer 20

Associated disorder of Transcription-coupled repair Rare autosomal recessive, congenital disorder involving mutant genes of ERCC6 and ERCC8 which code for proteins involved in TCR of DNA. If DNA is not repaired, cell dysfunction and cell death may occur. S/S: developmental and neurological delay, photosensitivity, premature aging (progeria) Death usually occurs in the first 2 decades of life

Answer 21

Unrepaired thymine dimers or apurini AP sites DNA polymerases

Answer 22

Single stranded polymer of ribonuceotides, each consisting of base, pentose sugar and phosphate, that link via 3'-5' phosphodiester bonds * more unstable than DNA * uses Uracil instead of thymine * can fold int 3-D structures

Answer 23

15% of total cellular RNA Metabolically stable Carry amino acids to ribosomes for incorporation into growing polypeptide chains

Answer 24

Structural and functional (catalytic) component of ribosomes Stable and long-lived 80%

Answer 25

Direct carrier of genetic information from genes to ribosomes for protein synthesis Short-lived 1-5%

Answer 26

Direct the splicing of pre-mRNA to from mRNA

Answer 27

Regulate eukaryotic gene expression by degrading select mRNA

Answer 28

Regulate gene expression by blocking translation of selective mRNA

Answer 29

Located in nucleolus Catalyzes the synthesis of a single large precursor rRNA (Makes ribosomal RNA)

Answer 30

Located in the nucleoplasm Catalyzes the synthesis of precursor mRNA, also synthesizes some snRNA and miRNA (Makes messenger RNA)

Answer 31

Located in nucleoplasm Synthesis of tRNA and snRNA

Answer 32

Non-template strand, indentical to the sequence of RNA that will be produced

Answer 33

+1 position of the gene that usually has an A or G. Site where the Basal transcription factors and the RNA polymerase bind

Answer 34

Poly A Tail (5' - AATAAA - 3') that is clipped off during RNA processing

Answer 35

Linear sequence of DNA from start to stop site

Answer 36

Sequence upstream of start site where basal transcription facts (initiation factors) bind and recruit the RNA polymerase

Answer 37

Short sequences present upstream, downstream, or in the transcription unit, and sites for binding of additional transcription factors that influence rate of transcription

Answer 38

1. Assembly of pre-initiation complex 2. Elongation 3. Termination - RNA polymerase binds to promoter on DNA - DNA double helix unwinds - One strand acts as a template for RNA synthesis and nucleotide sequence is determined by complementary base pairing that link by phosphodiester bonds - RNA polymerase catalyzes the reaction - RNA sequence is elongated in the 5' to 3' direction and released from the DNA as a single strand - RNA sequence is complementary to template and identical to coding strand

Answer 39

TRIID is recognized by TBP binds to TATA box, TFIIB, TFIIF, RNA pol II, TFIIE, and TFIIH are recruited and join

Answer 40

TFIIH unwinds the DNA double helix and exposes the DNA template strand

Answer 41

RNA pol II can function in absence of a primer and catalyzes formation of a dinucleotide using DNA as a template, capping enzyme adds 7-methyl guanosine cap on the 5' end

Answer 42

Protects against degradation and helps to bind mRNA to ribosome during translation, binds on 5' end of mRNA with a 5'-5' diphosphate linkage

Answer 43

Add acetyl group to histones, reduces positive charge and loosens interaction with DNA

Answer 44

Add back the acetyl grp and reverse action of HAT

Answer 45

Begins after formation of nascent RNA, RNA pol breaks interaction with promotor when the tail of RNA pol II is phosphorylated by TFIIH Elongation generates superhelical tension that is eased by DNA gyrase

Answer 46

Eases superhelical tension caused by elongation

Answer 47

Transcription ends when RNA pol encounters termination signals on the DNA template, RNA transcript forms a self complementary hairpin followed by a poly U tail

Answer 48

- modification of the 5' end of mRNA with the capping by 7-methyl guanosine - removal of introns or non-coding sequences by splicing - modification of the 3' end of mRNA by polyadenation (poly A tail)

Answer 49

Trans-acting proteins that regulate the transcription of genes across chromosomes. They have DNA-binding domains that enable them to bind to specific DNA sequences in the promoter or regulatory regions of genes. Transcription factors can either promote or repress the transcription of target genes. They bind as homo or heterodimers and recruit other proteins. Modulation of the activity of transcription factors usually involves phophorylation.

Answer 50

Contain a conserved 60 residue DNA biding motif or homeodomain

Answer 51

Have short regions containing Cys and His residues that interact with Zn ions that produce multiple loops or Zn fingers that insert into major grooves of DNA

Answer 52

Contain DNA binding sequence where every 7th residue is Leu which promotes dimerization and coiling of these sequences

Answer 53

Similar to zipper proteins except alpha helical regions separated by non-helical loop space

Answer 54

Inappropriate inactivation/activation of genes that control cell growth by deregulation of transcription factors may lead to cancer - mutated genes for TF's represent a significant fraction of oncogenes - mis-regulation may occur by aberrant increase in expression or by mutations in the coding sequence that alters activity of TF

Answer 55

Fragile X mental retardation (FMR1) - FMR1 gene encodes for a protein with neurological function - DNA sequence has excessive (>200) copies of CGG (compared to nl of 30) which makes it susceptible to methylation of cytosine - FMR1 gene becomes silent even though triplet expansion is upstream of protein coding sequence - as methylation repeat region extends into the promoter region, transcription is turned off

Answer 56

Amino to carboxyl (5' to 3')

Answer 57

Converts the nucleotide sequence of a gene into the amino acid sequence of a protein using mRNA as an intermediary

Answer 58

Group of 3 consecutive nucleotides in the RNA

Answer 59

There are 3 - UAA - UAG - UGA

Answer 60

AUG (methionine)

Answer 61

Silent Missense Nonsense Frameshift

Answer 62

Does not change the amino acid

Answer 63

Changes the amino acid in the protein with either no effect on protein function of a protein with vastly different function

Answer 64

Codon changes into a stop codon causing premature termination, protein either degraded or formed as a truncated version

Answer 65

One or more nucleotides are deleted or inserted into ORF, if out of frame causes change in the codon sequence and consequently alteration in the amino acid sequence Ie. Duchenne muscular dystrophy, beta thalassemia

Answer 66

A large ribosome subunit and small ribosome subunit assemble into an active ribosomal complex by the presence of mRNA. This complex has 3 important sites 1. Acceptor (A) site 2. Peptidyl (P) site 3. Empty (E) site

Answer 67

Location where the mRNA codon is exposed and set to receive all aminoacyl-tRNAs except initiating methionine tRNA

Answer 68

Location where the aminoacyl-tRNA is attached to the growing polypeptide chain (Methionine initiator binds here to start things)

Answer 69

Location that the empty tRNA occupies just prior to exiting the ribosome

Answer 70

Activated forms of amino acids that are esterified to the 3'-OH group of the 3' terminal adenine in the acceptor stem of their cognate tRNA Catalyzed by enzymes called aminoacyl tRNA synthetases * when an amino acid is bound, the tRNA is said to be charged

Answer 71

A two step process 1. Aminoacyl tRNA synthetase catalyzes the activation of amino acid by transferring AMP to COOH end 2. Transfers the amino acid for amino acid-AMP to cognate tRNA

Answer 72

Catalyze the activation process of tRNA charging

Answer 73

- tRNA binding - peptide bond formation - large subunit translocation - small subunit translocation

Answer 74

1. Initiation 2. Elongation 3. Termination

Answer 75

Pre initiator complex is assembled, then large subunit is added to form initiation complex, initiator tRNA bound to GTP attaches to P site of small subunit, the initiator tRNA-methionine complex loads onto the small su on the P-site, other initiation factors are added, the large su is added, and translation begins with the initiation codon AUG (methionine)

Answer 76

Activated amino acid attached to initiating methionine via a peptide bond, GTP-bound aminoacyl tRNA is loaded to the A site via GTP hydrolysis (anticodon and codon of A site base pair), peptide bond is catalyzed by petidyl transferase

Answer 77

Factors EF1 and EF 2 (EF-Tu and EF-G in bacteria) Proofread, making translation more efficient and accurate

Answer 78

Peptide chain is released from ribosomal complex which then dissociates into its components, Termination is triggered by stop codons (UAA, UAG, UGA) which are recognized by release factors from the tRNA, Release factors bind to A site and cleave the ester bond between the C terminus of the polypeptide and the tRNA, The catalyzation of a H2O molecule instead of an amino acid then adds COOH to the end of the polypeptide

Answer 79

Binds to the 30S ribosomal subunit in prokaryotes to disrupt the initiation of translation

Answer 80

Binds to the 60s subunit of eukaryotes to disrupt elongation

Answer 81

Binds to the 50S subunit in prokaryotes to disrupt translocation of the ribosomes

Answer 82

Bind to the 30S subunit in prokaryotes to disrupt elongation

Answer 83

Housed in the large subunits

Answer 84

Facilitate bind of the small ribosomal subunit to the initiator tRNA and base pairing between the anitcodon and codon

Answer 85

Provides the energy for assembly of the initiation complex

Answer 86

Additional initiation factors required for the assembly of the final 80S initiation complex in eukaryotes

Answer 87

Clusters of 10-100 ribosomes attached simultaneously to a single mRNA molecule, each synthesizing a polypeptide chain and making protein synthesis more efficient

Answer 88

Sites of protein synthesis depends on destination of protein 2 major pathways 1. Cytoplasmic pathway 2. Secretory pathway

Answer 89

For proteins destined for cytosol, mitochondria, nucleus, and peroxisomes - protein synthesis begins and ends on free ribosomes in cytoplasm - absence of presence of translocation signals play role in final targeting ** no translocation signals

Answer 90

For proteins destined for ER, lysosomes, plasma membranes, or for secretin - translation begins on free ribosomes but terminates on ribosomes sent to ER - proteins have ER targeting signal sequences present in the first amino acid residues of the polypeptide

Answer 91

Cytoplasmic pathway Proteins are passed across the mitochondrial membranes via translocator complexes TIM and TOM, unfolded proteins are protected by chaperones, specifically heat shock proteins 70

Answer 92

Transporter inner membrane Helps bring proteins into mitochondria

Answer 93

Transporter outer membrane Helps proteins pass across mitochondrial membrane

Answer 94

Chaperone that protects unfolded proteins passing through the mitochondrial membranes

Answer 95

Cytoplasmic pathway Utilized to imported large proteins into nuclear pores

Answer 96

Cytoplasmic Pathway No signal

Answer 97

Cytoplasmic pathway N-terminal hydrophobic alpha helix signal peptide

Answer 98

Cytoplasmic pathway KKKRK signal sequence

Answer 99

Cytoplasmic pathway C-terminal SKL signal sequence

Answer 100

Secretory pathway C-terminal KDEL retention signal And N-terminal hydrophobic alpha helix ER signal peptide

Answer 101

Secretory pathway Mannose-6-phosphate signal group And N-terminal hydrophobic alpha helix ER signal peptide

Answer 102

Secretory pathway Tryptophan-rich domain signal region, absence of retention motifs And N-terminal hydrophobic alpha helix ER signal peptide

Answer 103

Secretory pathway N-terminal apolar region (stop-transfer sequence) And N-terminal hydrophobic alpha helix ER signal peptide

Answer 104

KDEL K- Lysine D- Aspartic acid E- Glutamic acid L - Leucine

Answer 105

Each protein has an ER-targeting signal peptide that has: 1-2 basic amino acids near N terminus And an extremely hydrophobic sequence on C terminus of base residues Translation occurs on the ER

Answer 106

- Signal recognition particle (SRP) binds to the ER-targeting signal and the ribosome during translation, SRP wraps itself around ribosome-mRNA-peptide complex, halting translation which is resumed when the protein is directed into the ER lumen Enzymes on luminal side cleave signal to release protein, which undergoes PTM's Additional signal sequences guide each protein to its final destination

Answer 107

Protein folding Proteolytic cleavage Covalent modifications

Answer 108

Small proteins can fold into native confirmations spontaneously , large proteins require chaperones and chaperonins ex HSP60 that utilizes ATP to fold proteins

Answer 109

- converts inactive forms to active enzymes | - converts nascent precursor proteins to mature ones

Answer 110

- Glycosylation - phosphorylation - disulfide bond formation

Answer 111

Extracellular proteins (glycoproteins) that are either O-glycosidic of N-glycosidic linked

Answer 112

Formed with the hydroxyl groups of Ser or Thr residues

Answer 113

Always formed with asparagine, precursor sugar transferred from phospho Dolichol

Answer 114

Formation of an ester bond between phosphate and OH of an amino acid via activity of serine/threonine and tyrosine kinase Phosphate removed by phosphatases - regulates enzyme activity, protein function, cell growth, proliferation, differentiation, oncogenesis

Answer 115

Inter and intra-molecular disulfide bonds stabilize proteins, forming between thiol (SH) and two cysteine resides Formation and reorganization occurs in the ER lumen and is facilitated by protein disulfide isomerases

Answer 116

Produced as preproinsulin in B cells of pancreas Signal peptide cut off in ER lumen to form proinsulin Folds to form 2 intramolecular disulfide bridges Moves past golgi and accumulates in B granules Cleaved twice to release the 33 reside C peptide Forms mature insulin with A and B peptide joined by 2 disulfide linkages Stored in granules as a Zinc bound hexamer that is ready to be secreted

Answer 117

Used as a test for assessing function of beta cells

Answer 118

- Collagen is most abundant structure and hetermotrimeric - Lysines in procollagen hydroxylated to form 5'hydroxyl lysins that are further modified by glycosylation by addition of glucose and galactose - Prolines hydroxylated to from 4 and 3-hydroxyproline These modifications are necessary for correct crosslinking and assembly

Answer 119

Ehlers Danlos syndrome | Nevo syndrome

Answer 120

Essential for functioning of lysyl and prolyl hydroxylases

Answer 121

Specific place on a chromosome occupied by a gene

Answer 122

- temporarily holds 2 daughter DNA double helices together after DNA replication - attachment site for microtubules

Answer 123

Repeated nucleotide sequences at the end of a chromosome which are essential for chromosome stability

Answer 124

Entire set of stained chromosomes from a single cell

Answer 125

Chromosomes 1-22

Answer 126

Pair 23, male and female

Answer 127

Identical sisters present after DNA replication

Answer 128

Centromere is positioned in the center

Answer 129

Centromere is located near the telomere

Answer 130

Allows determination of number, size and gross structure of metaphase chromosome, used to identify several chromosomal abnormalities associated with genetic disorders, does not provide information at molecular level

Answer 131

Individual's genetic makeup

Answer 132

Physical manifestation of gentoype that is actually observed

Answer 133

First diagnosed person in pedigree

Answer 134

Only 1 allele needed for expression Affected offspring has one affected parent Unaffected individuals do not transmit trait Gender does not affect transmission Trait is expected in every generation Ie. Postaxial polydactyly

Answer 135

Trait is expected in every generation

Answer 136

Autosomal dominant inheritance, extra fingers

Answer 137

2 copies of a gene is needed to influence phenotype * Tyrosine-negative albinism

Answer 138

Autosomal recessive inheritance

Answer 139

Unaffected males do not transmit the trait (no carriers) Female carriers transmit affected allele 50% of the time All daughters of affected males are carriers Ex. Duchenne muscular dystrophy

Answer 140

X-linked recessive

Answer 141

No carriers Males transmit the trait to only females, 100% of whom are affected Females transmit trait to 50% of offspring ex. Hypophosphatemia

Answer 142

X-linked dominant - low levels of phosphorus in blood - abnormal metabolism of Vitamin D (can cause rickets)

Answer 143

Frequency a gene manifests itself

Answer 144

Range of phenotypes that vary between individuals with a specific genotype

Answer 145

Single disorder, trait, or pattern of traits caused by mutations in genes at different chromosomal loci Ex. Ostogenesis imperfecta

Answer 146

Locus Heterogeneity - brittle bone disease - mutations in collagen genes

Answer 147

Variable expressivity Develop tumor-like growths called neurofibromas, and develop cafe-au-lat-spots

Answer 148

Autosomal dominant inheritance

Answer 149

Alteration in gene that is present for the first time in one family member as a result of a mutation in a germ cell of one of the parents or in the fertilized egg itself

Answer 150

One gene influences two or more seemingly unrelated phenotypic traits

Answer 151

Time for acquisition of nutrients growth, and chromosome duplication

Answer 152

Separates the pairs of homologues with each daughter nucleus receiving one

Answer 153

Separates the chromatids and parcels one chromatid into each of two more daughter nuclei, produces four haploid daughter nuclei

Answer 154

Homologous chromosomes pair up and exchange DNA, crossing over occurs

Answer 155

Exchanged sections of DNA produced during crossing over

Answer 156

Genes on one homologue are combined with an allele from the other homologue , an the combination may be totally new

Answer 157

Paired homologous chromosomes line up at the equator of the cell, microtubules attach to kinetochore regions

Answer 158

Homologous chromosomes separate

Answer 159

Two haploid clusters of duplicated chromosomes form at each pole

Answer 160

Separates sister chromatids into four daughter nuclei

Answer 161

Condition in which cells from an individual who has developed from a single fertilized egg have different genotypes - all females have roughly equivalent populations of two genetically different cell types and are therefore a type of mosaic - ex. Down syndrome (trisomy 21), Klinefelter syndrome, Turner syndrome

Answer 162

(X-inactivation) one of the copies of X chromosome present in female mammal is inactivated because it is silenced by heterochromatin

Answer 163

Certain genes are expressed only from the mother or father, determined by methylation patterns on chromosomes - imprinted genes = methylation = down regulated - two chromosomes from same parent that have parent-specific imprinting = no gene product

Answer 164

Involve large segments of DNA, often encompassing millions of base pairs 4 types: - Inversion - Deletion - Duplication - Translocation

Answer 165

A segment of chromosomal DNA is present in its reverse orientation

Answer 166

Segment is lost

Answer 167

Homologs fail to separate properly - very common during egg development and increase with advancing maternal age - leading cause of spontaneous abortion and mental retardation in humans

Answer 168

Cells with abnormal chromosome number ie. Trisomy 21/ Down syndrome (90% of additional chromosomes in patients are maternal in origin)

Answer 169

Cells with normal number of chromosomes

Answer 170

Deletion on paternal chromosome 15 - uncontrolled eating and obesity - uniparental disomy

Answer 171

Deletion on maternal chromosome 15

Answer 172

Occurs when a person receives 2 copies of a chromosome from one parent and no copy from another parent - often asymptomatic, but can cause delayed development, mental retardation Ex. Prader Willi syndrome

Answer 173

Mosaicism Some cells are normal 46XY Other cells are an extra X chromosome 47XXY

Answer 174

Down Syndrome - mental retardation - abundant neck skin - Flat facial profile - congenital heart defect - umbilical hernia - hypotonia - gap between first and second toe - intestinal stenosis

Answer 175

Edwards Syndrome - Prominent occiput - mental retardation - Low set ears - short neck - overlapping fingers - congenital heart defect - renal malformations - limited hip abduction - rocker-bottom feet

Answer 176

Patau syndrome - Microcephaly - mental retardation - polydactylty - cleft lip and palate - cardiac defects - umbilical hernia - renal defects - rocker-bottom feet - microophthalmia

Answer 177

Punnet square Frequency of aa should be q-squared

Answer 178

Blood related couple (marriage of first cousins) indicated by double horizontal lines, more likely to produce offspring affected by rare autosomal diseases

Answer 179

Traits in which variation is thought to be caused by the combined effects of multiple genes Follows a normal bell-shaped distribution in populations

Answer 180

Environmental factors cause variation in the trait Follows a bell shaped distribution in populations

Answer 181

For multifactorial disease, this must be crossed before the disease is expressed

Answer 182

Muscular hypertrophy between stomach and duodenum, leading to vomiting and obstruction 5x more common in males children of women affected with pyloric stenosis are more likely to be born with the condition

Answer 183

Affected by gene frequencies and environmental factors that differ among populations

Answer 184

Recurrence risk is higher

Answer 185

Recurrence risk is higher

Answer 186

Recurrence risk is higher

Answer 187

Recurrence risk for the disease usually decreases rapidly

Answer 188

Caused by the simultaneous influence of multiple genetic and environmental factors

Answer 189

Random evolutionary process that produces larger changes in gene frequencies in smaller populations

Answer 190

Population that have started from a small group that mix with few newcomers, preferring to mate within the population * genetic drift

Answer 191

G1, S, and G2

Answer 192

Gap 1 RNA and protein synthesis occur in response to exogenous growth factors (mitogens) to create the proteins that are needed to replicate DNA in the next phase

Answer 193

Synthesis DNA is replicated, and RNA and proteins are synthesized

Answer 194

Gap 2 RNA and protein synthesis continues and the integrity (correctness, stability) of the DNA is checked as the cell prepares to split/divide into two

Answer 195

Mitosis Nuclear and cytoplasmic division occurs to create two identical daughter cells, phase is further divided into prophase, metaphase, anaphase, telophase, and cytokinesis

Answer 196

Resting stage Cells have excited the cell cycle and are not growing or dividing, however they synthesize just enough RNA and protein for general housekeeping of for specialized functions - quiescent state

Answer 197

1. permanent 2. Stable (quiescent) 3. Labile

Answer 198

Remain in the G0 phase and cannot be regenerated Ie. Cardiac muscle cells, neurons, and red blood cells

Answer 199

Retain the ability to exit G0 and enter G1 when stimulated by growth factors, allowing regeneration of damaged tissues Ie. Hepatocytes, epithelial cells of kidney tubules

Answer 200

Never enter G0 and are constantly dividing to replace cell populations that are continuously lost Ie. Gut epithelium, skin, hair follicles, and bone marrow

Answer 201

When growth factors are limiting, cell cycle is usually arrested in G1 at a point approximately 2 hours before the initiation of S phase Everything downstream is growth factor independent - when cells pass the restriction point, they become growth factor independent and transit through the remaining phases

Answer 202

Correct any DNA damage (chemical modification) before continuing

Answer 203

Verify completeness of complete genomic duplication

Answer 204

Ensures chromosomes are attached to mitotic spindle

Answer 205

``` G1: 2N S: Between 2N and 4N G2: 4 N M: 4N Cytokinesis: 2N ```

Answer 206

Somatic cells which are diploid contain 46 chromosomes Germline cells which are haploid contain 23 unpaired chromosomes

Answer 207

Regulatory subunit Proteins that regulate Cdks Without cyclin, Cdk is inactive

Answer 208

Catalytic subunit Inactive without Cdk

Answer 209

Helps the passage of cells through the restriction of point in late G1 phase - Cyclin D-CDK4 - Cyclin D- CDK6

Answer 210

Helps the cells at the end of G1 phase to commit to DNA replication and enter S phase - Cyclin E- CDK2

Answer 211

Necessary for the initiation of DNA synthesis - Cyclin A-CDK2

Answer 212

Necessary for the nuclear division during mitosis CyclinA - CDK1 CyclinB- CKD1

Answer 213

- heart of the cell-cycle control system - activities of Cdks rise and fall during cell cycle - causes changes in phosphorylation of substrates that regulate cell cycle events - Cyclins: proteins that regulate Cdks - without cyclin, CDK inactive

Answer 214

Required for the full activation of Cyclin-CDK complex Phosphorylates cdk

Answer 215

Ie. p27 of the CIP/KIP family binds to the cyclin-CDK complex to inactivate the kinase activity of CDK

Answer 216

Protein that blocks active site of Cdk and is removed by binding to cyclin, phosphorylation

Answer 217

CKIs bind to G1 and S phase cyclin, CDK complexes to inactivate the kinase activity of CDK

Answer 218

Family of CKIs that bind specifically to G1 CDKS to prevent them from associating with cyclin D

Answer 219

Enzyme that Phosphorylates CDK to inhibit cyclin-CDK activity

Answer 220

Gene regulatory protein

Answer 221

Tumor-supressor protein that can arrest the cell cycle at the G1 checkpoint, substrate of G1 and G1/S cyclin CDK complexes - hypophosphorylated form binds to E2F transcription factor to prevent transcription of cyclin E and cyclin A and proteins involved in DNA replication - Hyperphosphorylation by cyclin-CDK complexes releases the E2 factors to allow transition of cells past G1 checkpoint

Answer 222

Activation of p53 by DNA damage (caused by chemical or physical agens) activates protein kinases and leads to increased transcription of p21, a CKI which causes cell cycle arrest MDM2 keeps p53 inactive

Answer 223

A mechanism used to terminate the activity of cyclin-CDK complexes via degradation of the transiently expressed cyclin proteins. Cyclins are targeted by polyubiquitination catalyzed by ubiquitin ligases. Ubiquitin ligases can also target CKIs, thus releasing the inhibition of S phase cyclin-CDK complexes

Answer 224

Tumors develop due to unchecked division of precursor cells in the immature retina, hereditary: affects both eyes, RB gene is mutated or lost in every cell, if both copies are damaged the cells lose control at the G1 checkpoint Nonhereditary: affects one eye, cells contain different somatic mutations of the two copies of the RB gene

Answer 225

Phosphatase that can remove the phosphate group introduced by WEE1 to reactive the cyclin-CDK complex

Answer 226

metabolic Activated benzopyrene and Aflatoxin (carcinogens) cause mutations in genes such as p53 by G->T transversions

Answer 227

Human skin fibroblasts stop dividing after 30 to 50 population doublings even with abundant growth factors present due to shortening of telomeres with each cell division DNA damage leads to p53 mediated cell arrest at the G1 checkpoint

Answer 228

Extrinsic Pathway | Intrinsic Pathway

Answer 229

Member of ubiquitin ligase family of enzymes ** Degradation and cell turnover Targets S-cyclins and M-cyclins, adding polyubiquitin to M-cyclin in M-Cdk complex Activated by binding to Cdc20

Answer 230

Death receptor pathway, triggered by external binding and activation of an external death ligand to it receptor on the plasma membrane

Answer 231

Fas binds to Fas death receptor - ligand form homotrimers as well - adapter proteins are recruited: FADD adapter & procaspase-8 with death effector domain Activates downstream executioner caspases (caspase-3)

Answer 232

Caspase 8 must be formed to carry out apoptosis by activating caspase 3,6,7

Answer 233

Initiate apoptosis - Caspase 8 - Caspase 0

Answer 234

destroy actual targets Executes apoptosis and includes caspase 3

Answer 235

Cell cycle/apoptosis

Answer 236

Mitochondrial dependent - in response to injury, DNA damage, and lack of oxygen, nutrients, or extracellular survival signals - BAX/BCL regulators Cytochrome C is released from mitochondria, binds to Apaf1 Apaf1 forms apoptosome which activates caspase-9 Caspase-9 activates caspase-3 (executioner)

Answer 237

Forms apoptosome

Answer 238

Protein that becomes activate, forms aggregation in mitochondrial outer membrane and induces release of cytochrome C - the apoptosome is then formed by binding to Apaf1

Answer 239

Located on cytosolic surface of out mitochondrial membrane - prevent apoptosis by binding to pro-apoptotic proteins (BAX/BH123) and preventing aggregation into active form

Answer 240

Released from mitochondria, binds to procaspase activating adaptor protein (Apaf1) which actives caspase-9, which activates caspase-3

Answer 241

A group of cells/tissues change their fates in response to signals

Answer 242

Capacity to respond to inductive signal

Answer 243

- proteins with domains that bind to promoter or enhancer regions & domains that interact with RNA polymerase II - regulate amount of mRNA that gene produces * Homeobox - homeodomain containing genes/ Hox genes * T-box gene family * Helix-loop-helix (structure) * Zinc finger proteins (structure)

Answer 244

DNA sequence that encodes the homeodomain - involved in the regulation patterns of anatomical development (morphogenesis)

Answer 245

Homeo-box containing gene, classified by structure Long, repetitive elements of promoter elements that regulate anatomical development and then turn off Expressed and activated in the 3' to 5' direction Majorly regulated by retinoic acid TF

Answer 246

60 amino acid helix-turn-helix DNA binding domain

Answer 247

Vitamin A - regulates Hox genes

Answer 248

Play critical role in the formation of tissues and organs during embryonic development, maintains normal function in cells after birth Plays role in development of nervous system and sense organs Contain paired domain of 128 amino acids which bind to DNA - can turn on large amounts of proteins at one time TF

Answer 249

Involved in formation of virtually all body segments Large family of homeodomain proteins Absence can result in headless embryos TF

Answer 250

Growing of appendages, jaw, and inner ear Early embryogenesis TF

Answer 251

Prenatal - inhibits cell differentiation Postnatal - maintain proliferative capacity of tissues Also involved in epithelial-mesenchymal interactions in face & limbs TF

Answer 252

Important in mesodermal germ layer development Determines forelimb and hindlimb TF

Answer 253

Transcription factors that are named on appearance Regulate myogenesis

Answer 254

Regulates expression in genes involved in cell growth, proliferation, differentiation, and longevity * positive selection associated with human specific phenotype TF

Answer 255

Bind to minor groove in DNA & belong to a super-family of genes characterized by a homologous sequence called the HMG-box Regulate myogenesis * SoxA = SRY, sex determining region of Y chromosome TF

Answer 256

SRY, sex determining region of Y chromosome

Answer 257

Set of proteins that binds to ligand receptor complex and acts as a signal Binds to PTCH on surface of target cell, which is bound to SMO, a transmembrane protein *NOT a transcription factor

Answer 258

Proteins that bind to cell surface receptors Signal Ligands NOT TF

Answer 259

- RAS - HER2 - EGF receptor - N-MYC - c-MYC - ABL Working normally is fine, when mutated causes problems

Answer 260

Proto-oncogene Point mutation/deletion * point mutation changes glycine to valine at codon 12

Answer 261

- RAS - HER2 - EGF receptor

Answer 262

- HER2 | - N-MYC

Answer 263

c-MYC | ABL

Answer 264

Polymerase chain reaction (cell-free cloning) Used for diagnosing infections and genetic testing

Answer 265

B-cells are converted to secrete them

Answer 266

Antigen binding domain formed by heavy and light chains coming together

Answer 267

Specific site of the antigenic molecule the Fab region recognizes

Answer 268

Production of color indicates the amount of an antibody to a specific antigen

Answer 269

Production of color indicates the quantity of antigen

Answer 270

Can be used to detect altered genes or foreign DNA

Answer 271

Starting points for transcription - small (~20 nucleotides_ - complimentary to some portion of singe stranded DNA

Answer 272

ELISA Measures the levels of specific antigen or antibody concentrations in biological samples using a corresponding immobilized antibody or antigen

Answer 273

2-12 weeks * Use ELISA AND confirmatory PRNT

Answer 274

ELISA + confirmatory PRNT

Answer 275

FGF (fibroblast growth factor) Hedgehog proteins Transforming growth factor B (TGF-B) Superfamily WNT proteins

Answer 276

Transforming growth factor Involved in embryogenesis and postnatal life

Answer 277

Variation Broad spectrum of roles, closely associated with the ECM

Answer 278

Monitors checkpoints of cell cycle - tumors

Answer 279

Regulates G1 phase of cell cycle Observed in retinoblastoma

Answer 280

Regulates cell proliferation Colon cancer

Answer 281

Cell proliferation, migration, and apoptosis Colon cancer

Answer 282

DNA repair and apoptosis Breast cancer

Answer 283

Encodes GTPase-activating protein (GAP) which normally turns off activated RAS protein Neurofibromatosis

Answer 284

Transcription factor regulating Cdc25 protein tyrosine phosphatase (Growth regulation hormone)

Answer 285

Regulation of S/M phase transition Growth regulation gene

Answer 286

Cell survival

Answer 287

Change in activity or function of enzymes or proteins in a cell

Answer 288

Change in amounts of proteins by change in expression of genes

Answer 289

Released from fat Signals hypothalamus that you are full

Answer 290

- long distance Signal ->bloodstream-> distant target cells * freely diffusible signals * stable (Hormones)

Answer 291

Acts locally - affects cells nearby (not as freely diffusible) - short lived signal * ie. Neurotransmitters

Answer 292

- Cells respond to signals that they themselves release or release to cells of the same type - cells secretes signal that feeds back and binds to a receptor on its own surface * ie. Growth factors and cancer cells

Answer 293

Ie. Immune cells, Ag-presenting cells to T cells

Answer 294

Heart muscle cells : relax Skeletal muscle cells: contract Salivary gland cell: secretion of saliva

Answer 295

Cascade of events involving 1. signals (ligands) 2. Receptors 3. Effectors

Answer 296

- typically secreted by exocytosis - signals stay near or far Are either lipophilic or hydrophilic

Answer 297

Bind specifically to signal molecules with high affinity (signals are produced in low levels) - intracellular - cell surface receptor

Answer 298

Targets of receptors inside cells: alter activity of many different proteins and generate 2nd messengers like cAMP and Ca2+

Answer 299

Lipid-loving Steroid hormones Thyroid hormones Retinoids: Retinoic acid - found in the cytoplasm and nucleus - family of DNA-binding transcription factors

Answer 300

Water-loving, growth factors Amino acid derived From lipid metabolism Polypeptides - found on the surface of plasma membranes - includes transmembrane proteins such as G protein-coupled receptors and receptor tyrosine kinases

Answer 301

Steroid receptor in cytosol that can alter gene expression in the nucleus

Answer 302

External domain binds ligand, transmembrane domain anchors receptor, cytoplasmic domain initiates signal by change in conformation

Answer 303

Require cell-surface receptors

Answer 304

Can diffuse across the cytoplasmic membrane and bind to intracellular receptors

Answer 305

1. Gated ion channels common in nervous tissue 2. GPCRs use 7-pass transmembrane proteins 3. Enzyme-coupled receptor class including receptor tyrosine kinases (RTKs)

Answer 306

Composed of: - Extracellular domain - transmembrane domain - cytoplasmic domain GCPR -> Trimeric G protein -> effector enzyme -> 2nd messenger -> Targets of 2nd messenger -> biological response

Answer 307

Binds to ligand

Answer 308

Anchors receptor

Answer 309

Associates with G-proteins

Answer 310

Guanine nucleotide-binding proteins that consist of 3 subunits designated alpha, beta, and gamma Changes conformation if bound by a ligand

Answer 311

Phosphates

Answer 312

Guanine nucleotide exchange factor Phosphorylates GDP to GTP

Answer 313

GTPase activating protein Increases the intrinsic GTPase activity

Answer 314

1. Ligand binds to receptor 2. Conformational change occurs in receptors 3. Receptor binds to G protein 4. Receptor then acts as a GEF 5. Confirmation of a G alpha protein is changed to kick out GDP and GTP binds to it 6. G alpha now becomes active and can bind to effector molecule and activate effector molecule 7. Effector molecule in this case is adenylyl cyclase which catalyzes formation of cAMP

Answer 315

Catalyzes the formation of cAMP

Answer 316

Activates cAMP-dependent protein kinase (PKA) -4 subunits

Answer 317

2 catalytic subunits & 2 regulatory subunits

Answer 318

2 cAMP molecules bind to regulatory subunits of the PKA tetramer, releasing the active C subunits Active PKA can now phosphorylate other proteins

Answer 319

Derived from Vitamin A Excess results in broad spectrum of abnormalities *Acts through Hox genes

Answer 320

Catalyzes formation of DAG and IP3

Answer 321

Active form

Answer 322

Modifies G protein by keeping the G alpha in the GTP active form indefinitely This causes increase in cAMP PKA phosphorylates the CFTR cl- channel This leads to secretion of water

Answer 323

Ability to turn off or reject the signal * hormone levels drop (decreased AC, decreased cAMP

Answer 324

Removes signaling molecule (cAMP or cGMP) E.g. Viagra, keeps vasodilation high

Answer 325

G protein receptor kinases, phosphorylate the receptor

Answer 326

Will bind to the 3rd intracellular loop and prevents Ga from interacting with the third loop * requires GRK to phosphorylate the receptor first

Answer 327

IP3 and DAG by cleaving PIP2

Answer 328

Receptor tyrosine kinases Ligand binds and causes conformational change that opens up "docking sites" for phosphorylation Mediate growth factor signals

Answer 329

Proteins released by cells to promote growth of other cells

Answer 330

Bind to phosphotyrosine | T: Tyrosine and Two

Answer 331

Has SH2 and SH3 domains in SOS (REF)

Answer 332

Binds to prolines

Answer 333

Monomeric G protein, binds Raf

Answer 334

Son of sevenless, ras GEF

Answer 335

MAP kinase,

Answer 336

Raf (MAP kinase, kinase, kinase) -> Mek (MAP kinase, kinase) -> Erk (MAP kinase)

Answer 337

Kinases that phosphorylate each other

Answer 338

TGF-beta activates TGF beta receptors, Smads get phosphorylated and go to the nucleus

Answer 339

Adenylyl cyclases - inhibition of cAMP production, ion channels, phosphodiesterases, phospholipase

Answer 340

PLC-B DAG Ca2+ PKC

Answer 341

Adenylyl cyclases Increase in cAMP concentration

Answer 342

- Relaxation of bronchial and intestinal smooth muscle - Contraction of heart muscle - Increased breakdown of triacylglycerols in adipose tissue - Increased breakdown of glycogen in liver and muscle - Increased Glycolysis in muscle

Answer 343

- Bronchoconstriction and sx of allergic reaction

Answer 344

- constriction of smooth muscle

Answer 345

- increased heart rate

Answer 346

- Bronchoconstriction and stimulation of salivary glands

Answer 347

- Tyrosine kinases - JAK-STAT receptors - Serine/Threonine kinases * all create docking sites for other proteins

Answer 348

Bone or tendon, lots of extracellular matrix with sparse cell distribution

Answer 349

Cytoskeleton of cells linked cell to cell by that are anchored to the basal lamina

Answer 350

Cell-cell adhesion and cell-matrix adhesion, and are connected to cytoskeletal filaments inside the cell - Actin filament attachment sites - Intermediate filament attachment sites * integrins * cadherins

Answer 351

Seal gaps between epithelial cells so as to make the epithelial sheet into an impermeable barrier

Answer 352

Create passageways for small molecules and ions to pass from cell to cell

Answer 353

Allow signals to be relayed from cell to cell across their plasma membranes at cell-to-cell contact

Answer 354

Mediating cell-cell connection Bind to partner with Low affinity Mediate Ca2+ dependent

Answer 355

Mediating attachment of cells to matrix Alpha and beta subunits Always form a dimer

Answer 356

1. Cadherin 2. Intergrins 3. Selectins 4. Immunoglobulin-superfamily

Answer 357

Like cells bind to each other

Answer 358

Different cells come together

Answer 359

Main mediatiors of CA2+ dependent adherens junctions * E-cadherin

Answer 360

Desmocollins and demogleins that form desosome junctions

Answer 361

Link between cadherin and cytoskeleton

Answer 362

Model the shape of the cystoskeleton - often form continuous adhesion belt and contractile bundle of actin filaments ** cadherin is crucial component

Answer 363

Connects intermediate filaments in one cell to those in the next cell

Answer 364

Desmoglein and desmocollin Mechanical strength

Answer 365

Common cause of sudden cardiac death in the young due to improper insertion of desmocollin into the membrane

Answer 366

- form a seal between cells - form a fence between membrane domains - recruit cytoskeleton as well as signaling molecules * claudin * occludin

Answer 367

* claudin * occuldin - like claudins bind and like occludins bind

Answer 368

Par (partitioning defective), crumbs, and scribble - control polarization processes and maintain polarity

Answer 369

spanned by channel-forming proteins * connexins Couple cells both electrically and metabolically *** SMALL molecules like ions, nothing bigger than a glucose can go through

Answer 370

Causes channels to close immediately, isolating cell damage and preventing spread to other cells

Answer 371

Cells that secrete matrix macromolecules

Answer 372

Separates cells and epithelia from underlying or surrounding connective tissue and forms the mechanical connection between them Made up of : 1. Fibrous protein (ususally glycoproteins) 2. Glycosaminoglycan (GAG) polysaccharide chain

Answer 373

Lies between two cell sheets and functions as a selective filter

Answer 374

* laminin * collagen * fibronectin

Answer 375

Provides components to crawl * this is mediated by talin * focal adhesion knase.

Answer 376

Central signaling molecule downstream from integrins which activates erk and JNK to regulate cell survival, proliferation, and differentiation

Answer 377

Make up the matrix 1. Glycosaminoglycans (GAGs) 2. Fibrous proteins

Answer 378

Usually covalently linked to protein in the from of proteoglycans 1. Chondroitin sulfate 2. Dematin sulfate 3. Heparan sulfate 4. Keratan sulfate * strongly hydrophilic * form gels, providing mechanical support to tissue

Answer 379

Collagen and fibronectin, which have both structural and adhesive functions

Answer 380

Form highly hydrated, gel-like ground substance in which the fibrous proteins are embedded - bind to signal molecules and can enhance or inhibit their signaling activity * contain a special link tetrasaccharide attached to serine side chain on core protein Consist of long polysaccharides (GAGs) connected to protein core * polar, very hydrated (squishy tissue)

Answer 381

Old people drink for bones

Answer 382

Long polysaccharide/core complex linked to extensive hyaluronic acid chain

Answer 383

Repeating disaccharide ( glucaronic acid and N-acetylglucosamine), contains a lot of water, extremely long chain component of proteoglycan

Answer 384

Network forming

Answer 385

Bone, most abundant

Answer 386

Long, stiff, left handed triple-stranded helical structure (3 helical alpha chain) * filament * protofilament - rich in proline (kinks) and glycine (small, allows rope to pack tightly)

Answer 387

(lysyl/prolyl hydroxylases) Hydroxylation occurs in the ER * hydroxylation of proline is necessary for collagen production and connective tissue remodeling

Answer 388

Site of collagen etc. synthesis

Answer 389

Scurvy: loss of cofactor (ascorbate) Ehlers-Danlos VI: defective enzyme

Answer 390

Loss of cofactor ascorbate * prolyl/lysyl hydroxylases

Answer 391

Defective enzyme of prolyl/lysyl hydroxylase

Answer 392

Cross links protein via lysyl oxidase, can stretch and relax due to hydrophobic units Hydrophobic units line up and get rid of water

Answer 393

Mutation of fibrillin that goes into elastic fibers

Answer 394

Fatty subcutaneous layer

Answer 395

second layer, rich in collagen, provides toughness

Answer 396

- out covering of skin - water barrier - epithelial cells - continuously repaired and renewed

Answer 397

Secrete ECM and provide mechanical support

Answer 398

Attach to desmosomes

Answer 399

Grows upword from dermal papilla Have stem cells present in a bulge to aid in reconstruction

Answer 400

Nose: neural epithelium, renew approximately every 30 days

Answer 401

-light, taste, olfaction

Answer 402

Can bind to a single class of odorant molecules Activated olfactory receptor activates G-protein -> AC -> cAMP -> ion channels open -> influx of Na and Ca -> action potential

Answer 403

Determine the shape of the cells surface Necessary for whole-cell locomotion, secretion, endocytosis * compact and globular (G-actin vs. F-actin)

Answer 404

Determine positions of membrane-enclused organelles and direct the intracellular transport, centrioles & mitotic spindle, cilia & flagella * from tubulin, have polarity

Answer 405

Mechanical strength, strong filament, resist mechanical stress

Answer 406

Nucleation of actin filaments occurs near plasma membrane, so actin filaments mostly accumulate at cell periphery Actin filaments determine the shape and movement of the cell surface Nucleation of actin filaments by ARP complex creates polarity

Answer 407

Responsible for nucleation of microtubule growth

Answer 408

Most diverse group of intermediate filaments, anchor at sites of cell-cell contacts, desmosomes. Cell-matrix contacts (hemodesmosomes)

Answer 409

Formation of blood units, occurs in: Yolk sac : weeks 3-8 (splanchnic mesoderm) Liver: week 6-30 (2nd trimester) Spleen: Weeks 9-28 (2nd trimester) Bone marrow: 28 weeks - adult Adult: lymph, bones of axial skeleton (skull, vertebrae, ribs, sternum, clavicle, pelvis, long bones)

Answer 410

Red and yellow Compartments: Hematopoietic cell compartment Marrow stromal compartment

Answer 411

Highly vascular | Stem cells

Answer 412

White cells

Answer 413

Production of growth factors Barrier: separates hematopoietic compartment from central longitudinal vein Removal of dead cells and debris (macrophage) Energy source: adipose tissue

Answer 414

Erythroblast compartment, removes dead cells and debris

Answer 415

Endothelial cells, separate blood cells from vein

Answer 416

All starts off as red

Answer 417

Based on the presence of apidocytes (fat cells)

Answer 418

In balance between red and yellow

Answer 419

Reticular connective tissue Adipocytes and macrophages

Answer 420

Between cords | Allow cells into circulatory system

Answer 421

Capable of self-renewal | Pleuripotent

Answer 422

Red blood cells

Answer 423

Monocyte and neutrophil

Answer 424

B lymphocyte, T lymphocyte

Answer 425

BFU, CFU-mega, CFU-GM, eosinophil, basophil

Answer 426

Colony-stimulating factors Erythropoietin, thrombopoietin Cytokines

Answer 427

Produced by fetal tissues and bone marrow Weak stimulator of hematopoiesis Makes stem cells responsive to other cytokines

Answer 428

Acts on pluripotent stem cells

Answer 429

Influenced replication and growth potential of hematopoietic progenitors

Answer 430

Acts on pluripotent stem cells to develop the lymphoid stem cells

Answer 431

T-cell growth factor

Answer 432

B-cell growth factor

Answer 433

Stimulates formation of all leukocytes | Less potent than G-CSF for increasing neutrophils

Answer 434

Stimulates increase in neutrophils

Answer 435

Stimulates increase in monocytes and macrophages

Answer 436

Stimulate RBC formation | Produced in kidney

Answer 437

Produced in the liver Stimulated increase in megakaryocytes and platelets

Answer 438

Deliver Ox from lungs to tissues Picks up CO2 from tissues and unloads it on the lungs

Answer 439

Secrete vasoconstrictors Stick together to form temporary platelet plug

Answer 440

Large central nucleus Ribosomes make hemoglobine Mitotic

Answer 441

Smaller nucleus Patchy chromatin Basophilic cytoplasm Mitotic

Answer 442

``` Smaller nucleus Condensed chromatin Light blue staining clumps of polyribosomes Light pink staining hemoglobin Mitotic ```

Answer 443

Dense, eccentric nucleus Pink cytoplasm No mitosis

Answer 444

1% of circulating RBCs | No nucleus

Answer 445

Mature cell, no nucleus

Answer 446

Produced in kidney in response to hypoxia

Answer 447

Megakaryoblast -> megakaryocyte -> platelets

Answer 448

Large oval nucleus Basophilic cystoplasm Becomes megakaryocyte

Answer 449

Mutilobed nucleus Endomitos Forms platelets

Answer 450

Nuclear division occur without cell division

Answer 451

Regulates megakaryocyte and platelet development Produced in live, kidney, and bone marrow

Answer 452

- heteromchromatin content increases - no specific granules from - no nuclear lobulation - cell sizes decreases * lymphocytes and monocutes

Answer 453

- chromatin condenses - cytoplasmic granules - nucleus become lobulated - cell size decreases ** neutrophils, basophils, eosinophils

Answer 454

Phagocytize bacteria Release antimicrobial chemicals

Answer 455

Phagocytize antigen-antibody complexes, allergens, and inflammatory chemicals Antiparasitic and bactericidal activity

Answer 456

Secrete histamine and heparin Inflammatory reactions during immune responses and allergies

Answer 457

Myeloblast -> promyelocyte -> myelocyte -> metamyelocyte -> band -> polymorphonuclear neutrophil

Answer 458

No cystoplasmic granules Mitotic large round euchromatic nucleus

Answer 459

Large flattened nucleus More condensed chromatin Azurophilic granules present Mitotic

Answer 460

Indented nucleus Specific granules accumulate Smaller than promyelocyte Mitotic

Answer 461

Meta "beyond" Deeply indented nucleus Densely packed specific granules NO mitosis

Answer 462

Horseshoe shape nucleus Chromatin condensed and lobulated Higher numbers indicate infection

Answer 463

Mature cell

Answer 464

Monoblast -> Promonocyte -> Monocyte -> macrophage

Answer 465

Large round euchromatic nucleus No cytoplasmic granules Mitotic Indentical to myeloblast

Answer 466

Large slightly intended nucleus Divide several times before becoming monocytes

Answer 467

Mature cell

Answer 468

Emigrated blood monocytes that differentiate in tissues Found at sites of infection

Answer 469

T and B cells

Answer 470

Secrete antibodies Mature in bone marrow

Answer 471

Destroy cancer cells, virus infected cells, foreign cells Mature in thymus

Answer 472

Nucleus 1-2 nucleoli No cytoplasmic granules

Answer 473

Primitive cell that can either self-renew or give rise to more specialized cell types

Answer 474

Ability of cell to give rise to all cells of an organism *** Zygote

Answer 475

Ability of a cell to give rise to all cells of the embryo and subsequently adult tissues *** embryonic stem cells

Answer 476

Ability of a cell to give rise to different cell types of a given lineage *** adult stem cells

Answer 477

Can divide as stem cells giving rise to one daughter cell that remains a stem cell and a set of cells that have a set number of transit amplifying division - define size of large final structures - controlled by short range signals - each organ/tissue has fixed number of founder cells

Answer 478

Divide frequently Programmed to divide for a limited number of times Part of strategy for growth control Derived from founder cells Daughter cell

Answer 479

Creates 2 cells, one with stem cell characteristics and another with factors that give it the ability to differentiate

Answer 480

Creates 2 identical cells but environment may influence/alter 1 cell

Answer 481

Gets new synthesized strand Original DNA strand is preserved in stem cell

Answer 482

From blastocyst stage of embryo Can proliferate indefinitely in culture with unrestricted developmental potential Develops into different cell types with characteristics appropriate for that site

Answer 483

Mixture of differentiated cells

Answer 484

Oct 3/4 Sox2 Myc Klf4

Answer 485

Found in cord blood, bone marrow, and peripheral blood

Answer 486

Found in wharton's jelly, bone marrow, adipose tissue, and tooth pulp

Answer 487

Have memory of developmental history and seems committed to its fate, which limits its clinical use

Answer 488

Make up connexins of gap junction

Answer 489

Consists of 2 noncovalently associated subunits Alpha and beta Beta: binds to complex of proteins that form a linkage to the cytoskeleton Alpha: active integrin

Answer 490

Glycoprotein Mutation can cause Marfan's syndrome

Answer 491

Attach to basal lamina Only dividing cells in epidermis

Answer 492

Attach to basal cell layer Contain desmosomes that attach tufts of keratin filaments

Answer 493

Attach to prickle cells - seal together to form waterproof barrier - form boundary between inner metabolically active strata and outer dead epidermis cells

Answer 494

Outermost layer - flattened dead cells, densely pack with keratin but no organelles

Answer 495

Cells continue to divide even after exit from basal layer

Answer 496

Loss of sebaceous glands

Answer 497

Extra hair follicles develop, giving rise to tumors

Answer 498

Leads to failure of hair follicle development

Answer 499

Size of stem cell population

Answer 500

Plays key role in repair of skin wounds promoting formation of collagen rich scar tissue

Answer 501

Organize the centrosome matrix, ensuring its duplication during each cell cycle Attach to mitotic spindles Arranged at a right angle to each other

Answer 502

Promotes actin polymerization at the cell periphery -> formation of lamellipodia extensions

Answer 503

Caused by Rac activation

Answer 504

Triggers actin polymerization and bundling to from filopodia

Answer 505

Triggered by cdc42 activation

Answer 506

Promotes the bundling of actin filaments into stress fibers

Answer 507

- CSF: G-CSF, GM-CSG, M-CSF - Erythropoietin & Thrombopoietin - Interleukines: IL-3, IL-2, IL-6

Answer 508

Immune rejection is not an issue because the patients are using their own cells *early stem cell

Answer 509

Oct3/4, Sox2, Myc, Klf4

Answer 510

These transcription factors are essential for establishment and maintenance of pluripotent stem cells in the embryo

Answer 511

Homeodomain

Answer 512

Zinc finger protein

Answer 513

Homeodomain

Answer 514

Cell proliferation (acts directly on cyclin expression) Proto-oncogenes

Answer 515

Helix-loop-helix transcription factors

Answer 516

Zinc finger protein

Answer 517

Works with B-catenin (downstream of Wnt signaling)

Answer 518

Homeodomain * control differentiation during development of head and limbs

Answer 519

Growth factors that bind membrane receptors - control transcription factor activation of differentiation genes

Answer 520

Cells and plasma (fluid component) can be separated by centrifugation

Answer 521

Percentage of erythrocyte volume: RBC's constitute about 45% of blood volume

Answer 522

- non-nucleated - biconcave - no organelles - consist of plasma membrane, cytoskeleton, hemoglobin, and glycolytic enzymes

Answer 523

RBC's rely on spectrin for flexibility to fit through capillaries and to maintain a certain shape to house glycolytic enzymes and hemoglobin

Answer 524

Alteration of RBC shape due to cytoskeleton defect (defective self association of spectrin subunits, defective binding of spectrin to ankyrin, protein 4.1 defects, abnormal glycophorin) * oval shaped RBCs - autosomal dominant

Answer 525

Alteration in shape of RBC due to cytoskeleton defect (deficiency in spectrin) * anemia, jaundice, splenomegaly - autosomal dominant

Answer 526

Hemoglobin abnormality caused by point mutation where glutamic acid is replaced by valine on hemoglobin chain, hemoglobin aggregates and is ineffective at binding oxygen * cells are sickle shaped - chronic hemolytic anemia, obstruction of post-capillary venules

Answer 527

Hemoglobin abnormality caused by defective synthesis of alpha or beta chains of hemoglobin tetramer * anemia

Answer 528

Hemolytic disease of the newborn: mother is Rh- and child is Rh+, creating antibodies that can "attack the mother"

Answer 529

1. Neutrophils 2. Eosinophils 3. Basophils - multi-lobed nucleus - contains primary and secondary cytoplasmic granules

Answer 530

1. Lymphocytes 2. Monocytes - contain only primary granules

Answer 531

60-70% of circulating leukocytes | - act to eliminate opsonized bacteria or limit the extent of an inflammatory reaction in connective tissue

Answer 532

2-4% of circulating leukocytes (can also enter connective tissue) - first defense against parasites * trigger bronchial asthma

Answer 533

1% of circulating leukocytes (can also enter connective tissue) - play roles in bronchial asthma and allergic skin reactions

Answer 534

20-40% of circulating leukocytes 1. B lymphocytes 2. T lymphocytes

Answer 535

- Made in bone marrow - Antigen stimulated B cells differentiate into antibody secreting plasma cells - Mature in bone marrow

Answer 536

- Made in bone marrow - Participate in cell mediated immunity - Mature in thymus

Answer 537

2-8% of circulating lymphocytes * circulate in blood for 12-100 hours then enter connective tissue - involved in bacterial phagocytosis, antigen presentation, and clean-up of dead cell debris - in bone, monocytes differentiate into osteoclasts

Answer 538

Defect in beta subunit of integrin * leukocytes cannot leave blood vessels and enter tissues - clinically, inflammatory cell infiltrates are devoid of neutrophils

Answer 539

Fucosyl containing ligands for selectin are absent * leukocytes cannot leave blood vessels and enter tissues

Answer 540

- Mast cells degranulate and release chemical mediators, causing neutrophils and eosinophils to enter the connective tissue of the respiratory mucosa - eosinophils release additional factors to enhance bronchoconstriction which damage the cell lining and disturb mucociliary function

Answer 541

- Carbohydrate ligands on surface of neutrophil bind to selectin molecule expressed on endothelial cell - Integrin LFA-1 on surface of neutrophil binds to ICAM-1 on surface of endothelial cell

Answer 542

Plays an important role in wound healing, immune surveillance, tumor metastasis and tissue morphogenesis

Answer 543

1. Megakaryocytes develop cytoplasmic projections that become proplatelets 2. Proplatelets fragment into platelets

Answer 544

Promote blood clotting and help to precent blood loss from damaged vessels

Answer 545

Reduction in number of platelets in blood, leading to increased susceptibility to bleeding * caused by: - decrease in platelet production - increase in platelet destruction - aggregation of platelets in the microvasculature

Answer 546

Inability of platelets to attach to subendothelial vascular surfaces * caused by deficiency in glycoprotein 1b-factor iX (von willebrand's factor)

Answer 547

von Willebrand's factor - important in aggregation of normal platelets when they are exposed to injured subendothelial tissues

Answer 548

Autosomal dominant Characterized by macrothrombocytopenia

Answer 549

Reduced number of platelets in the blood, but remaining platelets in the blood have an increase in size/volume

Answer 550

Associated with macrothrombocytopenia * Defect in myosin heavy chain IIA - causes defective formation of platelets during formation of proplatelets

Answer 551

120 days, RBCs are constantly removed from circulation and replaced

Answer 552

Transport metabolic gases * O2 from lungs to the tissue * CO2 from tissue to lungs

Answer 553

Hemocytoblast, proerythroblast, early erythroblast, late erythroblast, nomoblast, reticulocyte (can enter bloodstream), erythrocyte

Answer 554

65% made before extrusion of nucleus 35% made in reticulocyte

Answer 555

Necessary for DNA synthesis Deficiency would impact RBC's and cause megaloblastic anemia

Answer 556

Oxygen transporter Tetramer of 2 alpha chains and 2 beta chains (4 subunits) One heme per subunit 8- alpha helical segments that provide stability

Answer 557

- has iron atom (Fe2+/ferrous) - hydrophobic - carries O2 - one per subunit (4 per molecule) * one molecule can carry 4 O2

Answer 558

2 alpha and 2 gamma subunit

Answer 559

2 alpha, 2 beta

Answer 560

Alpha 2 | Delta 2

Answer 561

Defect on beta gene of HbS at 6th position substituting valine for glutamic acid -> polymerization of hemoglobin and sickle cell shape Induction of expression of HbF can utilize gamma gene to help carry out the function of the defective beta gene

Answer 562

Only 2 Oxy and deoxy

Answer 563

Myoglobin (monomer) : hyperbolic curve Hb (tetramer) : sigmoid shape

Answer 564

All hemes act together - all bind Or -all unload

Answer 565

Shifts Oxygen dissociation curve (ODC) to the right * more is produced at high altitude

Answer 566

Fetal Hb has higher affinity for O2 than mother's Hb * HBF does not bind well to 2,3-BPG

Answer 567

Fetal Hb has higher affinity for O2 than mother's Hb * HBF does not bind well to 2,3-BPG

Answer 568

Dietary iron in Ferric form (Fe3+) is reduced to Fe2+ by Dcytb to enter the enterocyte After being expelled from the enterocyte it is transformed back into Fe3+

Answer 569

Carries iron to tissues where it is needed including bone marrow in a non-toxic form *** On average, 30% of transferrin is bound to iron (transferrin saturation)

Answer 570

Iron deficiency

Answer 571

Fe overload

Answer 572

High TBIC Organ dysfunction due to iron overload

Answer 573

Deficiency in B12 and folate - large erythrocytes - nl Hb content in relation to size

Answer 574

Cobalamin Has Cobalt, protoporphyrin like ring, nucleotide, sugar, nitrogen ring * Accepts methyl from folate, releasing THF (FH4)

Answer 575

Pteridine PABA Glutamate

Answer 576

Becomes one-carbon donor for synthesis of nucleotides (methylene)

Answer 577

Deficiency in B12 will lead to deficiency in Folic Acid because N5-methyl-THF needs B12 to demethylate it in order to enter the folic acid cycle

Answer 578

Primary circulating form of THF in bloodstream " folate Trap"

Answer 579

Made by parietal cells of stomach, carries B12 to ileum where receptors bring it into body

Answer 580

Degrade R-binder proteins in duodenum to release B12

Answer 581

Made by gastric mucosa celss, bind to dietary B12 in stomach

Answer 582

Circulates through the blood carrying cobalamin

Answer 583

Lack of intrinsic factor causing Vitamin B12 deficiency * Pernicious means death - gastric mucosa is destroyed - decrease in IF * Use Schilling test

Answer 584

Give oral Co-labeled B12 & inject B12 Collect urine in 24 hours Cobalamin B12 not absorbed : pernicious anemia & part 2 B12 and radioactivity absorbed/seen in urine: B12 deficient diet is answer

Answer 585

B12 deficient diet

Answer 586

Pernicious anemia Give oral dose Co-B12 + IF Collect urine in 24 hours If radioactive B12 present: pernicious anemia due to lack of IF

Answer 587

No production of ATP in blood cells

Answer 588

Should be 30%

Answer 589

Yellowing of skin/eyes Excess bilirubin in blood stream (hyperbilirubinemia) *imbalance between production and excretion of bilirubin Can be pre-hepatic, intra-hepatic, or post-heaptic

Answer 590

3 phases 1: Mitochondria 2. Cytosol 2. Mitochondria

Answer 591

Glycine + Succinyl CoA -> ALA via ALA synthase

Answer 592

Condensation of 2 delta-ALA -> porphrobilogen 4 porphobilinogens -> coproporphyrinogen III

Answer 593

Coproporphyrinogen III install side-chain vinyl groups in protoporphyrinogen IX, which make ring system of protoporphyrin IX, Fe2+ is installed by ferrochelatase making heme

Answer 594

Caused by Defects in one or more stages of heme synthesis Inherited metabolic disorders * hepatic -> neuological sx Erythropoietic -> skin phosensitivity

Answer 595

Needs pyridoxal phosphate - inhibited by heme and hemin - mRNA contains an iron response element

Answer 596

Neurologic symptoms

Answer 597

Skin, photosensitivity

Answer 598

defect in PBG deaminase - hepatic Excess ALA and PBG Abdominal pain

Answer 599

Uroporphyrinogen III synthase defect, causes build up of Uroporphyrinogen I which is oxideized to uroporphyrin I (Bad) -Erythropoietic Photosensitivity, Excess uroporphyrin I

Answer 600

Defect in uroporphyrinogen decarboxylase - hepatoerythropoietic **MOST common in US Excess uroporpyrinogen III

Answer 601

Defect in protoporphyrinogen IX oxidase - hepatic Photosensitivity, neurologic sx

Answer 602

Variegate prophyria

Answer 603

Degrades hemoglobin Globin broken down into amino acids Heme removed for degradation

Answer 604

Enzyme that removes bridge between pyrrole rings of heme * requires oxygen * releases Co2 * iron oxidized from ferrous to ferric - synthesizes Biliverdin (green)

Answer 605

Bilirubin released from spleen into bloodstream - binds to albumin because it is insoluble, and is then transported to liver In hepatic microsomes, Bilirubin is conjucated with glucuronic acid to make direct BR which is soluble

Answer 606

Enzymes in liver that conjugate free bilirubin with UDP-glucuronic acid make bilirubin-monoglucuronide and diuronide

Answer 607

Yellow pigment in urine

Answer 608

Gives feces its brown color

Answer 609

Increased production of unconjugated BR Causes: - excess hemolysis - internal hemorrhage - capacity of liver uptake/excretion of BR is exceded - Glucose-6-PO4- dehydrogenase deficiency - Neonatal incompatibility of maternal-fetal blood Findings: *** ELEVATED blood levels or unconjugated or indirect BR Direct BR is absent in urine Urobilinogen present in urine Nl AST and ALT Nl blood levels of conjugated BR

Answer 610

General liver dysfunction - impaired hepatic uptake, conjugation, or secretion of conjugated BR * Liver cirrhosis * hepatitis * Criggler-Najjar syndrome (conjugation defect) * Gilbert syndrome (conjugation defect) Findings: Increase in unconjugated and conjugated BR Increase in ALT and AST Nl urobilinogen levels in urine Conjugated BR detected in urine

Answer 611

Problems with BR excretion (decreased bile flow) - Obstruction - Cholelithiasis - Liver disease - lesions - drugs Findings: ``` ELEVATED blood levels of conjugated BR Small increase in unconjugated form Nl AST and ALT Elevated bile salt levels Conjugated BR in urine (dark color) No urobilinogen in urine No stercobilin in feces (pale) Elevated alkaline phosphatase ```

Answer 612

akak Pysiological jaundice 1. Breakdown of fetal hemoglogin 2. Immature hepatic metabolic pathways 3. Deficiency of UDP-GT enzyme * accumulation of excess BR in blood leads to jaundice

Answer 613

Used to treat jaundice, BR changes conformation to more soluble isomer when exposed to fluorescent light

Answer 614

Type I: complete abscence of the gene - deficiency of UDP-GT which conjugates BR * severe hyperbilirubinemia * encephalopathy in babies due to accumulation of BR in brain

Answer 615

Encephalopathy associated with BR accumulation in brain and Crigler-Najjar syndrome

Answer 616

Benign form - mutation in UDP-GT gene, enzyme has less activity

Answer 617

Reduced activity (25%) of UDP-GT

Answer 618

Liver inflammation leading to liver dysfunction - increased levels of unconjugated and conjugated BR in blood * jaundice * dark urine

Answer 619

Reddish brown

Answer 620

1. Deliver requirements for cell metabolism 2. Remove waste products 3. Homeostasis 4. Immune response

Answer 621

Consists of: - electrolytes - proteins - small organics - lipids

Answer 622

- WBC's - RBC's - Platelets * all arise from pluripotent stem cell

Answer 623

Oxygen | Nutrients

Answer 624

Carbon dioxide | Metabolites

Answer 625

Hormones | Thermoregulation

Answer 626

Bluish/dark coloring of lips and skin Result of hemoglobin in blood that doesn't have enough oxygen associated with it

Answer 627

% of blood that is cells

Answer 628

Process of producing red blood cells - occurs in bone marrow

Answer 629

Deliver oxygen to tissue * Our bodies use the amt. of 02 getting to our tissues to determine how many RBC's we need - this is sensed mostly in the kidney, but also in the liver

Answer 630

* most made in liver - albumin - globulin - enzymes

Answer 631

- complement - kinin - clotting - fibronolytic

Answer 632

The kidney

Answer 633

- HIF accumulates (hypoxia inducible factor) - HIF triggers erythropoietin in the kidney - RBC production occurs (Erythropoiesis)

Answer 634

Hypoxia inducible factor - increases erythropoietin - increases transferrin

Answer 635

Connects to JAK/STAT pathway - act on stem cell to increase differentiation into proerythroblasts and maturation rate * prevents apoptosis of erythroid stem cells

Answer 636

Change oxygen binding

Answer 637

- adequate general nutrition - iron availability - Vitamin B12 - Folic acid

Answer 638

Iron deficiency, RBC's are smaller than normal

Answer 639

Total amount of oxygen that can be carried in our blood assuming every available heme has an oxygen bound to it 1.34ml O2/ g hb x g hb/L blood

Answer 640

Amount of oxygen that is actually being carried in our blood | Oxygen capacity x % saturation

Answer 641

1.34 mL of oxygen

Answer 642

% of available hemes with oxygen bound

Answer 643

Obtained via anaerobic glycolysis - Prevents oxidation of Hemoglobin - Maintains ferrous form of iron - ion transport - Membrane flexibility

Answer 644

Rupture of cell

Answer 645

Presence of large amounts of iron in the Ferric (Fe3+) state in heme

Answer 646

In spleen by macrophages Hb is broken down - iron receycled - heme broken down to bilirubin

Answer 647

Decreased # of RBC's - decreased Hb content * folate/B12 deficiency * iron deficiency * bone marrow damage * kidney damage + decreased oxygen capacity and content + decreased oxygen delivery to tissue + increased work load on heart + viscosity of blood is reduced Oxygen saturation is unchanged

Answer 648

Excess RBC's More oxygen carrying capacity + increased viscosity of blood + increased cardiac effort + increased oxygen content and capacity Oxygen saturation is unchanged

Answer 649

Nl bone marrow Kidneys respond to low oxygen levels due to - altitude (physiological polycythemia) - lung/heart disease

Answer 650

Bone marrow is making RBC's when there is no need to (abnormal) * can be related to thrombopoietin receptor mutation Erythropoietin levels are low

Answer 651

Valine replaces glutamic acid on the surface of the beta chain in hemoglobin on chromosome 11

Answer 652

New pulmonary infiltrate on CXR Respiratory distress

Answer 653

Streptococcus pneumonia

Answer 654

Vaso-occlusion in the spleen secondary to sickle cells - spleen is rapidly enlarged and reticulocyte increases