The Nucleus and Nucleic Acids (pp.140-145)

1. Nuclear structure
   a.  Nuclear envelope and pores
   b.  Nucleoplasm and nucleoli
   c.  Chromatin
   
2. Organization of chromatin
   a.  Nucleosome structure
   b.  Supercoiling of DNA
   c.  Nonhistone proteins
   
3. Nucleotides-monomers of DNA and RNA
   a.  Sugar-phosphate backbone
   b.  Nitrogenous bases
   
   • Pyrimidines-single ring
     • Cytosine (C)
     • Thymine (T)
     • Uracil (U)
   • Purines-double ring
     • Adenine (A)
     • Guanine (G)
4. DNA structure
   a.  Sugar-phosphate backbone
   b.  Nitrogenous base
   c.  Double helix
   d.  Complementary base pairing
   
   • Purine-pyrimidine pairs
     • A across from T
     • G across from C
   • Reasons for these pairs
     • Size of purine and pyrimidine
     • Number of hydrogen bonds
5. DNA function
   a.  Codes for structure of proteins
   b.  Genes and the genome
   
6. RNA structure and function
   a.  Smaller and single-stranded
   b.  Ribose replaces deoxyribose
   c.  Uracil replaces thymine
   d.  Interprets code in DNA
   e.  Directs protein synthesis
   

Protein Synthesis and Secretion (pp.145-152)

1. The genetic code
   a.  Four nucleotides representing 20 amino acids
   b.  DNA base triplets and RNA codons
   c.  Stop and start codons
   
2. Transcription
   
3. Posttranscriptional modification
   
4. Movement of mRNA into cytoplasm
   
5. Translation
   a.  Attachment of ribosome to mRNA
   b.  Binding to tRNA
   c.  Growth of peptide chain
   d.  Polyribosomes
   
6. Chaperones and protein structure
   
7. Posttranslational modification
   a.  Role of leader sequence
   b.  Changes occurring in ER cisterna
   c.  Formation of transport vesicles
   d.  Changes occurring in Golgi complex
   
8. Packaging and secretion
   a.  Golgi vesicles
   b.  Secretory vesicles and exocytosis
   

DNA Replication and the Cell Cycle (pp.152-158)

1. DNA replication
   a.  Unwinding from histones
   b.  Uncoiling by DNA helicase
   c.  Replication by DNA polymerase
   d.  Splicing by DNA ligase
   e.  Rewinding around new histones
   f.  Semiconservative nature of DNA replication
   
2. Errors and mutations
   a.  Error rates in bacteria
   b.  Proofreading and error correction
   c.  Effects of mutations
   
   • None if new base sequence codes for same amino acid sequence as old
   • None if amino acid substitution is in a noncritical part of a protein
   • Genetic defects if substitution is in a critical part of the protein
3. The cell cycle
   a.  G₁ phase: normal cellular functions
   b.  S phase: DNA replication
   c.  G₂ phase: preparation for mitosis
   d.  M phase: nuclear and cytoplasmic division
   e.  G₀ phase: cells that have left the cycle
   
4. Functions of mitosis
   a.  Embryonic development
   b.  Tissue growth
   c.  Replacement of old and dead cells
   d.  Repair of injury
   
5. Stages of mitosis
   a.  Prophase
   
   • Nuclear envelope disintegrates
   • Chromatin condenses into chromosomes
   • Mitotic spindle begins to form
   b.  Metaphase
   
   • Chromosomes line up on equator
   • Spindle fibers attach to centromeres
   c.  Anaphase
   
   • Centromeres divide
   • Sister chromatids move apart
   d.  Telophase
   
   • Chromosomes decondense
   • Nuclear envelopes form
   • Mitotic spindle breaks down
6. Cytokinesis: cytoplasmic division
   
7. Timing of cell division
   a.  CDC proteins present throughout cell cycle
   b.  Cyclins appear in M phase
   c.  Cyclin-dependent kinases (Cdks)
   d.  Mitosis suppressed by contact inhibition
   
8. Cancer
   a.  Tumors and oncology
   b.  Benign versus malignant tumors
   c.  Causes of cancer
   
   • Carcinogens-environmental agents
   • Mutations
   d.  Growth factors
   e.  Oncogenes
   
   • Involved in embryonic development
   • Reactivated later by carcinogens
   • Code for growth factors or receptors
   f.  Tumor suppressor (TS) genes
   
   • Possible modes of action
   • TS gene mutations and cancer
   g.  Effects of cancer
   
   • Loss of organ function
   • Compression of tissues and organs
   • Energy diversion

Chromosomes and Heredity (pp.159-163)

1. The karyotype
   a.  Twenty-three pairs of homologous chromosomes
   
   • Autosomes (22 pairs)
   • Sex chromosomes (X and Y)
   b.  Germ cells and somatic cells
   c.  Haploid and diploid cells
   d.  Maternal and paternal chromosomes
   
2. Genes and alleles
   a.  Gene loci
   b.  Alleles
   c.  Genotype and phenotype
   d.  Homozygous and heterozygous genotypes
   e.  Dominant and recessive alleles
   f.  Heterozygous carriers
   
3. Multiple alleles, codominance, and incomplete dominance
   
4. Polygenic inheritance and pleiotropy
   
5. Sex linkage
   
6. Penetrance and environmental effects
   
7. Alleles at the population level
   

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