CSET: Cell Biology and Physiology

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CSET: Cell Biology and Physiology
2012-12-27 23:56:38

Biology CSET
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  1. Compare prokaryotic cells, eukaryotic cells, and viruses in terms of complexity, general structure, differentiation, and their requirements for growth and replication
    • eukaryotic cells:
    • has a true nucleus and membrane-bound organelles
    • generally quite bigger
    • divide by mitosis

    • prokaryotic cells:
    • no true nucleus or other membrane-bound organelles
    • smaller
    • simpler in structure
    • reproduce by binary fission
    • greater nutritional diversity

    • viruses:
    • smallest
    • protein shell called capsid encloses the viral genome
    • some have viral envelopes
    • can only reproduce within a host cell
  2. Describe the stages of the cell cycle
    • interphase - longest stage, cell grows and copies its chromosomes:
    •         G1 phase - first gap, cell grows
    •         S phase - synthesis, continues to grow as it copies its chromosomes
    •         G2 phase - second gap, grows more as it completes preparations for cell division

    mitotic (M) phase - mitosis and cytokinesis, cell divides
  3. Diagram and describe the stages of the mitotic process

    prophase: chromatin condense and become visible, nucleoli disappear, mitotic spindle begins to form

    prometaphase: nuclear envelope fragments, microtubules extend from each centrosome toward the middle of the cell

    metaphase: longest stage, chromosomes lined up in the middle, spindle of microtubules is complete

    anaphase: shortest, two sister chromatids of each pair separate and begin moving toward opposite ends as their kinetochore microtubules shorten

    telophase: two daughter nuclei begin to form, nuclear envelopes begin forming from fragments of parent cell's envelope, chromosomes become less condenses
  4. Diagram the structure of the cell membrane and relate the structure to its function

    • tails of hydrocarbons change to adjust fluidity of membrane
    • membrane proteins have different structures according to their functions
    • the fluid mosaic model allows selective permeability
    • the hydrophobic core impedes the direct passage of ions and polar molecules
    • membranes are permeable to specific ions and polar molecules through transport proteins
  5. Explain methods of transport across the membrane
    diffusion: a substance will diffuse from where it is more concentrated to where it is less concentrated

    passive transport: diffusion of a substance across a membrane without an energy investment

    facilitated diffusion: passive transport aided by transport proteins, specific

    active transport: uses energy to move solutes against their gradients

    endocytosis: the cell takes in macromolecules and particulate matter by forming new vesicles from the plasma membrane

    exocytosis: the cell secretes macromolecules by the fusion of vesicles with the plasma membrane
  6. Explain the role of semipermeable membranes in cellular communication
    signal molecules bind to specific sites on receptor proteins embedded in the cell's plasma membrane
  7. Explain the role of the endoplasmic reticulum and Golgi apparatus in the secretion of proteins
    • ER secretes proteins produced by the ribosomes
    • Golgi takes transport vesicles containing secretory proteins and modifies, stores and sends them to their destinations
  8. Explain the role of chloroplasts in obtaining and storing usable energy
    • site where photosynthesis occurs
    • light energy is converted into chemical energy
  9. Explain the role of mitochondria in cellular respiration
    site of cellular respiration - process that generates ATP by extracting energy fro sugars, fats and other fuels with the help of oxygen
  10. Explain the role of enzymes in chemical reactions and describe an experiment to tests the catalytic role of enzymes and factors that affect enzyme activity (eg levels of protein organization, temperature, ionic conditions, concentration of enzyme and substrate, pH)
    enzymes speed up metabolic reactions by lowering the activation energy barrier by enabling the reactant molecules to absorb enough energy to reach the transition state even at moderate temperatures
  11. Explain anabolic and catabolic pathways involved in the metabolism of macromolecules (eg polysaccharides, nucleic acids, proteins, lipids)
    anabolic - dehydration removes a water molecule, forming a new bond

    catabolic - hydrolysis adds a water molecule, breaking a bond
  12. Relate the complementary activity of major body systems (eg circulatory, digestive, respiratory, excretory) to provide cells with oxygen and nutrients and remove waste products
    • the digestive system takes in food and absorbs nutrients, which it passes to the circulatory system to travel to the rest of the body
    • the respiratory system take in O2 and takes out CO2 which travels through the circulatory system
    • the excretory system removes waste from the circulatory system
  13. Explain and analyze the role of the nervous system in mediating communication between different parts of the body and the body's interactions with the environment
    • the nervous system forms a communication and coordination network throughout the body
    • the brain contains neurons that carry electrical signals from one part of the body to another
    • each neuron communicates with other neurons to form networks
  14. Explain the homeostatic role of the major organs (eg kidneys, heart, brain)
    kidneys - regulates the amount of water and solutes in body-fluids

    heart - pumps blood throughout the body to bring cells oxygen and remove CO2

    brain - hypothalamus in the brain is the homeostatic control center, controls pituitary gland and regulates body temperature, blood pressure, hunger, thirst, sex drive, fight or flight response
  15. Explain the function of feedback loops in the nervous and endocrine systems to regulate conditions in the body and predict the effects of disturbances of these systems
    • feedback loops maintain homeostasis of normal levels of a product or normal levels of activity of production of a product
    • disturbances of these systems can cause an over display or under display of the action of the hormone
  16. Explain the role of hormones (eg digestive, reproductive, osmoregulatory) in providing internal feedback mechanisms for homeostasis at the cellular level in whole organisms
    hormones are produced through the endocrine system that cause an action somewhere in the body and these hormones are regulated by the nervous system or other hormones or level present in the blood
  17. Describe the role of the musculo-skeletal system in providing structure, support and locomotion to the human organism
    • the skeletal system provides anchoring, support and protection
    • the muscular system is made up of skeletal muscles that are attached to the skeleton and produce body movement by interacting with the skeleton
  18. Explain the humoral response to infection
    the humoral response is the secretion of antibodies into the blood and lymph by effector B cells
  19. Compare cell mediated and humoral responses to infection
    humoral - involves antibodies secreted by effector B cells into the blood and lymph

    cell mediated - effector T cells respond directly to antigens that have already entered body cells, carried out directly by effector cells rather than antigens
  20. Explain how vaccination works and distinguish among variables affecting success rate
    • the immune system is confronted with a vaccine composed of a harmless variant of a disease-causing microbe or one of its parts
    • the vaccine stimulates the immune system to mount defenses against these antigens and these defenses will also be effective against the actual pathogen because it has the same antigens
  21. Predict the consequences of a compromised immune system (eg AIDS)
    people with a compromised immune system are susceptible to infections that would not ordinarily cause a problem