bio exam 2

34 flashcards · Other · by Victoria Solomon

  1. Q: Why are phospholipids considered amphipathic molecules?

    A: Phospholipids possess both a hydrophilic head and hydrophobic tails.

  2. Q: How do hydrophobic molecules cross cell membranes?

    A: Hydrophobic molecules primarily cross cell membranes through simple diffusion.

  3. Q: What is the difference between channel proteins and carrier proteins?

    Channel Proteins: Provide a direct path for specific ions and small molecules to move through the membrane quickly and passively. Carrier Proteins: Undergo conformational changes to transport larger molecules across the membrane and can be involved in both passive and active transport processes

  4. : What is diffusion?

    A: Diffusion is a physical process in which particles spread from an area of high concentration to an area of low concentration until equilibrium is reached.

  5. Distinguish among osmosis, facilitated diffusion, and active transport.

    Osmosis: Movement of water. Facilitated Diffusion: Transport of specific molecules without energy. Active Transport: Requires energy to move substances against their concentration gradient.

  6. : How does an electrogenic pump create voltage across a membrane?

    Electrogenic Pump: An ion transport protein that creates voltage by moving ions unevenly across a membrane. Example: Sodium-potassium pump (Na+/K+ ATPase). Ion Movement: Pumps 3 Na+ out and 2 K+ in, resulting in a net loss of positive charge inside the cell. Energy Source: Requires ATP for active transport.

  7. Q: What is chemiosmosis in the context of the electron transport chain?

    Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient

  8. How does the electron transport chain utilize chemiosmosis?

    Electrons are transferred through protein complexes (Complex I to IV) in the inner mitochondrial membrane. Energy from electron transfers is used to pump protons (H+) into the intermembrane space, creating a proton gradient.

  9. : What are the characteristics of asexual reproduction?

    Process: Mitosis Cell Division: Involves a single round of cell division. Products: Results in two genetically identical daughter cells. Function: Recovery and healing.

  10. Q: What is the process of sexual reproduction?

    Process: Meiosis Function: A specialized type of cell division that reduces the chromosome number by half. Products: Produces gametes (sperm and eggs) in animals.

  11. Q: When and how are chromosomes duplicated?

    Interphase (S phase): Chromosome duplication occurs. G1 Phase: Cell grows and synthesizes proteins and organelles. S Phase: DNA replication occurs, resulting in duplicated chromosomes (sister chromatids). G2 Phase: Cell prepares for mitosis.

  12. What are the key events of each phase of the cell cycle?

    Interphase: Longest part, consisting of three sub-phases: G1 Phase: Cell growth and metabolic activity. S Phase: DNA replication and centrosome duplication. G2 Phase: Further growth, DNA checkpoint, and preparation for mitosis.

  13. : What occurs during prophase in mitosis?

    Chromatin Condensation: Chromatin condenses into visible chromosomes. Nuclear Envelope Breakdown: The nuclear envelope begins to break down. Spindle Formation: The mitotic spindle begins to form from the centrosomes.

  14. What happens during metaphase in mitosis?

    Chromosome Alignment: Chromosomes align at the metaphase plate (equatorial plane). Spindle Fiber Attachment: Spindle fibers attach to the centromeres of the chromosomes.

  15. : What occurs during anaphase in mitosis?

    Sister Chromatid Separation: Sister chromatids are pulled apart towards opposite poles of the cell. Cell Elongation: The cell begins to elongate as the chromatids move

  16. What happens during telophase in mitosis?

    Chromosome Decondensation: Chromatids reach the poles and begin to decondense back into chromatin. Nuclear Envelope Reformation: The nuclear envelope re-forms around each set of chromosomes.

  17. What is cytokinesis?

    Cytoplasmic Division: The cytoplasm divides, resulting in two daughter cells. Formation of Cell Membrane: In animal cells, a cleavage furrow forms; in plant cells, a cell plate forms

  18. What are sex chromosomes and autosomes?

    Autosomes: 22 pairs of chromosomes that consist of somatic cells. Sex Chromosomes: Determine sex and consist of gametes

  19. What is the difference between diploid and haploid cells?

    Diploid (2n): Cells containing two complete sets of chromosomes (e.g., 46 in humans). Haploid (n): Cells containing one complete set of chromosomes (e.g., 23 in humans).

  20. What is the purpose of meiosis I?

    The purpose of meiosis I is the reduction of chromosome number from diploid to haploid.

  21. : What key events occur during prophase I of meiosis?

    Chromosomes condense and become visible. Homologous chromosomes pair up (synapsis), forming tetrads. Crossing over occurs, allowing for genetic recombination.

  22. Q: What happens during anaphase I of meiosis?

    A: Homologous chromosomes are pulled apart to opposite poles (sister chromatids remain together).

  23. What is the purpose of meiosis II?

    : The purpose of meiosis II is the separation of sister chromatids, similar to mitosis.

  24. : What occurs during telophase II of meiosis?

    Chromosomes de-condense, and nuclear membranes reform. Cytokinesis occurs, resulting in four genetically diverse haploid cells.

  25. Q: What is the purpose of mitosis?

    : To produce two genetically identical daughter cells for growth, repair, and asexual reproduction.

  26. What are the phases of mitosis?

    Prophase: Chromosomes condense and become visible; spindle fibers form. Metaphase: Chromosomes align at the metaphase plate. Anaphase: Sister chromatids are pulled apart to opposite poles. Telophase: Nuclear membranes reform around the two sets of chromosomes, followed by cytokinesis, which divides the cytoplasm.

  27. : What is the purpose of meiosis?

    : To produce gametes (sperm and eggs) for sexual reproduction, reducing the chromosome number by half.

  28. What are the phases of meiosis I?

    Prophase I: Homologous chromosomes pair up and undergo crossing over. Metaphase I: Tetrads align at the metaphase plate. Anaphase I: Homologous chromosomes are pulled apart. Telophase I: Two haploid cells are formed.

  29. What are the phases of meiosis II?

    Prophase II: Chromosomes condense again; spindle apparatus forms. Metaphase II: Chromosomes align individually at the metaphase plate. Anaphase II: Sister chromatids are pulled apart. Telophase II: Four haploid cells are produced after cytokinesis.

  30. Q: How do the products of mitosis and meiosis differ?

    Mitosis produces two genetically identical daughter cells. Meiosis produces four genetically diverse haploid cells.

  31. glycolysis

    2 Pyruvate 2ATP NADH

  32. Pyruvate Oxidation

    2 Co2 2NADH 2 Acetyl CoA

  33. Citric Acid cycle

    4 Co2 6NADH 2FADH 2ATP

  34. Fermentation purpose

    keeps glycolysis going, keeps ATP going , make NAD+, oxidize