Chapter 1: The Cell

• Eukaryotes have membrane-bound organelles, a nucleus, and may form multi-cellular organisms
  • Organelles: nucleus (contains DNA), nucleolus (part of nucleus where rRNA is made), mitochondria (the powerhouse of the cell), lysosomes (hydrolytic center of the cell), rough ER (permits translation of proteins to be secreted), smooth ER (lipid synthesis and detoxification), Golgi (modifies, packages, and directs things), peroxisomes (break down long fatty acids).
• The Cytoskeleton elements
  • Microfilaments (play a role in cytokinesis), Microtubules (make cilia and flagells and are found in centrioles), and Intermediate Filaments (diverse group that is involved in cell-cell adhesion or maintenance of cytoskeleton's overall integrity)
• Epithelial Tissue: protect against pathogen invasion and desiccation. can be involved in absorption, secretion and sensation. they constitute the parenchyma (the functional parts of the organ).
• Connective Tissue: supports the body and provides a framework for the epithelial cells to carry out their functions. they are the main contributors to the stroma (support structure).
  • examples: blood, bone, cartilage, tendons, ligaments, and adipose tissue
• Archaea and Bacteria are the two domains that contain prokaryotes.
  • Archaea are usually extremophiles. single-celled organisms that are more similar to eukaryotes than to bacteria.
  • Bacteria share analogous structures with some biochemical differences. some are parasites, mutualistic symbiotes, or pathogens.
• Aerobes and Anaerobes
  • obligate aerobes: require oxygen for metabolism. obligate anaerobes: can't survive in an oxygen environment. facultative anaerobes: can do either aerobic or anaerobic metabolism (depending on environment). aerotolerant anaerobes: are unable to use oxygen for metabolism, but don't die in an oxygen rich environment
• Ways that prokaryotes do genetic recombination:
  • Transformation: foreign genetic material is put into a host genome.
  • Conjugation: a bridge is formed between two cells and genetic material is transferred (it is the bacterial form of sexual reproduction)
  • Transduction: recombination process that require a vector to carry genetic material from one bacterium to another
• Viruses are composed of genetic material, a protein coat, and sometimes a lipid-containing envelope
• Viruses can't survive or replicate outside of a host cell
• Bacteriophages are viruses that target bacteria. They contain a tail sheath that injects genetic material into the bacteria and tail fibers that allow the phage to attach to the host cell. (They look like those crazy alien things from Chicken Little)
• Prions are misfolded proteins that increase its resistance to degradation (think Alzheimer's).
• Viroid is a plant pathogen that are small circles of complementary RNA that can turn off genes (and result in cell death if it is extreme enough).
• Retroviruses are single-stranded RNA viruses that carry reverse transcriptase to make the DNA from their RNA. A common example is HIV.
• Lytic cycle is when the cell lyses and pours lots of new virions into the cell. The lysogenic cycle is when the virus integrates into the host genome and reproduces along with the cell (until it leaves and enters lytic cycle or it can stay indefinitely).

Chapter 2: Reproduction

• Order of Cell Cycle: G1, S, G2, M. (Interphase is G1, S, and G2)
  • G1: cells create organelles for energy and protein production and increase their size.
  • S: the cell replicates so that each daughter cell can get identical genetic material.
  • G2: cell checks to make sure there are enough organelles and cytoplasm for the daughters.
• p53 plays a role in the G1 to S checkpoint and the G2 to M checkpoint (Cyclin and CDK also help activate transcription factors for the next cell cycle stage)
• Mitosis: start with 2n and end with 2n.
  • Stages: PMAT (Prophase, Metaphase, Anaphase, Telophase and Cytokinesis)
  • Prophase: chromosomes condense, spindle forms.
  • Metaphase: chromosomes align
  • Anaphase: sister chromatids separate
  • Telophase: newnuclear membranes form