Potpourri Flashcards
What are the leading causes of death from most deaths to least deaths?
1) Heart disease: 596,577
2) Cancer: 576,691
3) Chronic lower respiratory diseases: 142,943
4) Stroke (cerebrovascular diseases): 128,932
5) Accidents (unintentional injuries): 126,438
6) Alzheimer’s disease: 84,974
7) Diabetes: 73,831
8) Influenza and Pneumonia: 53,826
9) Nephritis, nephrotic syndrome, and nephrosis: 45,591
10) Intentional self-harm (suicide): 39,518
List what comprises the human body from most abundant to least abundant
Water (60%)»_space; Protein > Fat/Lipids»_space; Inorganic Salts > Carbohydrates > Nucleic Acids
List ions that are most abundant extracellularly
1) Calcium (10,000:1)
2) Chloride (30:1)
3) Sodium ion (15:1)
4) Bicarbonate (3:1)
List ions that are most abundant intracellularly
1) Organic Salts/Phosphate ions (50:1)
2) Potassium ion (30:1)
3) Magnesium ion (20:1)
4) Hydrogen phosphate buffer (5:1)
What are three classes of membrane proteins?
1) Integral (Transmembrane)
2) Peripheral
3) Lipid-anchored
What is the glycocalyx and what are its functions?
It is a cell coat that functions to: 1) protect the cell (net negative charge repels proteins)
2) contains receptors for binding ligands
3) facilitates cell-cell recognition
How do you isolate the plasma membrane of an erythrocyte?
Place it in a hypotonic solution. It will causes the heme to be removed from the RBC (increases concentration of surrounding solution) and causes water to enter the RBC (reduces concentration of RBC)
What are two secretory pathways?
Exocytosis and Endocytosis
What are types of endocytosis?
1) Fluid phase endocytosis (pinocytosis)
2) Receptor-mediated endocytosis
3) Phagocytosis
What are three types of metaphase chromosome classifications?
1) Metacentric - centromere in middle with roughly equal length arms
2) Submetacentric - arm lengths are unequal
3) Acrocentric - p arm (short arm) is so short that it is hard to observe (still exists, however)
What occurs during Prophase of mitosis?
1) Chromosomes condense
2) Spindle assembles
What occurs during Metaphase of mitosis?
1) Chromosomes are aligned at the equator of the spindle
2) Paired kinetochore microtubules on each chromosome attach to opposite poles of the spindle
What occurs during Anaphase of mitosis?
1) Paired chromatids synchronously separate to form two daughter chromosomea
2) Each chromatid is pulled slowly toward the spindle pole it faces
3) Kinetochore microtubules get shorter and the spindle poles also move apart
What occurs during Telophase of mitosis?
1) Chromosomes arrive at the spindle pole
2) Nuclear envelope reforms
3) Contractile ring forms (cleavage furrow)
4) Mitosis ends
What occurs during cytokinesis?
1) Cytoplasm divides
2) Cell division is complete
What holds chromatids together during metaphase?
During metaphase, securin blocks separase. This prevents separase from cleaving the cohesins that hold chromatids together
How do chromatids separate during anaphase?
During anaphase, anaphase promoting complex (APC) is activated. APC is an ubiquitin ligase that causes securin proteolysis. This releases separase and cleaves cohesins
Nondisjunction leads to ______
Aneuploidy
What are the phases of meiotic prophase 1?
1) Leptotene
2) Zygotene
3) Pachytene
4) Diplotene + diakinesis
What happens at the end of prophase 1?
1) Sister chromatids are linked at a chiasma
2) Recombination/crossing over occurs (requires hybridization between homologous maternal and paternal chromosomes)
What are two trisomies that occur from nondisjunction in meiosis?
1) Trisomy 21 - Downs Syndrome
2) Trisomy 18 - Edwards Syndrome
Mitosis occurs in ____ cells. Meiosis occurs in _____ cells.
Somatic; Germline
How many divisions occur in mitosis and meiosis and what are the results?
Mitosis - One cell division yields identical daughter cells (2N)
Meiosis - Two cell divisions yield 4 haploid gametes (1N). Genotype of gametes is NOT identical
What happens to the chromosome number after mitosis and after meiosis?
Mitosis - Constant chromosome number (2N = 46 in humans)
Meiosis - Chromosome # is halved
When does S phase occur in mitosis and meiosis?
Mitosis - before mitosis
Meiosis - before Meiosis I only; not between Meiosis 1 and 2
How often does recombination occur between homologous chromosomes in mitosis and in meiosis?
Mitosis - Pairing of homologous chromosomes and recombination is rare
Meiosis - 1-2 recombinations per homologous chromosome
When do centromeres divide in mitosis and meiosis?
Mitosis - centromeres divide at anaphase
Meiosis - Centromeres only divide at anaphase II (Not anaphase I)
How much energy do the energy carriers carry in relation to each other?
Creatine Phosphate > ATP > ADP > Pyro-phosphate > AMP
Incomplete penetrance is very common for what type of traits?
Autosomal dominant
By which inheritance pattern are structural protein deficiencies usually transmitted?
Autosomal dominant
What are two types of loss-of-function mutations and what do they do?
1) Recessive - enzymes (you can usually lose half of a particular enzyme and still have virtually complete function - especially if the enzyme does not catalyze the rate-determining step)
2) Dominant - structural proteins (e.g. collagen; membrane components and receptors - can’t lose a large amount of these)
The first step in identifying a candidate gene is linking the gene to known markers. Which of Mendel’s principles is implicitly violated by this approach?
Independent Assortment (Second Law)
How can one test for gene linkage?
Conduct a dihybrid cross. If there is no gene linkage, then there should be four genotypes in equal proportions. Check %recombinance for gene linkage as well
What is Cytochrome P450 used for?
Cytochrome P450 encodes the CYP genes CYP2D6, CYP2C9, & CYP2C19
What are the 5 major polymorphisms?
SNP, RFLP, VNTR, SSR, & CNV
Which type of polymorphism is demonstrated in the repetitive structure of telomeric DNA?
SSR (TTAGGG)
What are nucleotides used to indicate splice sites?
GU-AG
What are four characteristics of mitochondrial inheritance?
1) maternal inheritance
2) heteroplasmy
3) mosaicism
4) low penetrance
Is mitochondrial replication dependent on the cell cycle?
No, it is independent.
How is can DNA structure be described from its most basic form to most complex?
DNA double helix –> Nucleosomes –> Solenoids (winding of 5 nucleosomes) –> Nucleofilament –> Chromosome
What is the eukaryotic equivalent of SSB (single strand binding protein)?
RPA (Replication protein A) - Stabilize single-stranded DNA
What is the eukaryotic equivalent of DnaA?
ORC (Origin replication complex) - bind to initiation site
What is the eukaryotic equivalent of DnaB?
MCM (Mini chromosomal maintenance proteins) - Unwind DNA ahead of replication complex
What is the eukaryotic equivalent of DnaG (primase)?
DNA Pol alpha primase - RNA Primer synthesis
What is the eukaryotic equivalent of DNA Pol III and DNA Pol I respectively?
DNA Pol epsilon & DNA Pol alpha/delta - DNA synthesis
What is the eukaryotic equivalent of DNA Pol I for Primer Removal?
removal by enzymes (Such as RNase H)
What is the eukaryotic equivalent of DNA Ligase?
DNA Ligase - Okazaki fragment joining
What is the eukaryotic equivalent of tus (terminus utilization substance)?
Nothing - termination of replication
Compare the number of replication forks in prokaryotes and eukaryotes and indicate why they are so
Prokaryotes - 2 replication forks for one replication bubble. DNA is much shorter and only requires one to be efficiently transcribed
Eukaryotes - Multiple replication forks and bubbles needed to efficiently transcribe long DNA
How many RNA polymerases do prokaryotes and eukaryotes have respectively?
Prokaryotes - 1
Eukaryotes - 3
What is the order of formation of the transcription factor initiation complex in transcription?
TBP (TFIID), TFIIB, TFIIF, TFIIE, TFIIH
