Biological Sciences II

  1. What are the functions of skin?
    • 1. Physical barrier against pathogens
    • 2. Regulation of body temp (1) Sweating (2) Regulation of body temp by dilation of blood vessels in skin.
    • 3. Excretion of excess water and salts
  2. Why does the mitochondrial genome come from the mother?
    Following penetration, the sperm-derived mitochondria disintegrate within the egg; so they cannot be replicated when divisions begin.

    Sperm have large numbers of mitochondria for locomotion.

    Genes coding for mitochondria are found in mitochondrial DNA - not on XX chromosome.
  3. If two proteins have the same number of amino acids, but they differ from each other by one amino acid, the genes must differ by:

    A. one amino acid
    B. three codons
    C. at least one nucleotide
    D. at least three nucleotides
    At least one nucleotide.

    A codon, which codes for a single amino acid in the final protein, consists of 3 nucleotides.

    At least one nucleotide must be changed to code for a different amino acid. Changing 3 nucleotides can also lead to a change in a single amino acid, as long as they're in the same codon.
  4. How many nucleotides contribute to one amino acid?
    3 nucleotides
  5. For gel electrophoresis, pretend that the top is negative and the bottom is made positive. Where would large molecules migrate towards?
    Large molecules would migrate towards the negative end.
  6. How do enantiomers differ in physical or chemical properties? How would a reactant distinguish between them?
    They don't.

    A reactant would distinguish between them by having stereospecific properties.
  7. For K+ or Na+, when does repolarization take place? depolarization? hyperpolarization?

    What is the order?
    Repolarization takes place when potassium channels are opened.

    Hyperpolarization is due primarily to flux of K+ ions out of axon.

    Depolarization takes place when voltage gated sodium channels allow sodium flow into axon

    • 1. Depolarization
    • 2. Hyperpolarization
    • 3. Repolarization?
  8. How to determine when something is sp2 vs sp3?
    If there's DELOCALIZATION of lone pairs in a unhybridized p orbital, then it's SP2. Otherwise, it's sp3. 
  9. What's more acidic: phenol or alcohol?
    PHENOL, due to resonance stabilized delocalization
  10. Where can the carbonyl stretch occur in IR?
  11. Where is bile produced? Where is bile stored? Where is urea produced?
    Bile & urea are produced in the liver. Bile is stored in the gallbladder for fat emulsification. 
  12. How does sarcomere shortening occur?
    • (1) Regulated by nerve cell impulse which results in:
    • (2) Release of Ca2+ ions from specialized ER: sarcoplasmic reticulum found in all muscle cells
    • (3) Presence of Ca2+ to troponin on myosin allows conformational change in sarcomere so that tropomyosin that covers the binding site of myosin on the actin filaments is displaced. 
    • (4) This allows myosin to bind to ACTIN
  13. What hormones are released by the posterior pituitary gland?
    ADH & Oxytocin
  14. Draw basic structure of an enamine, imine, imide, and amide
    Image Upload 1

    Image Upload 2
  15. What happens when a B-hydroxyketone is heated?
    It will undergo dehydration to form an a-B unsaturated carbonyl. 
  16. Draw the basic mechanism for nucleophilic acyl substitution
    Image Upload 3
  17. What would not occur in response to lowered blood insulin levels? 

    B. Increased utilization of glucose as fuel.

    This is because insulin levels are reduced at times of low blood glucose to conserve glucose for the brain. 
  18. What should you assume if someone given a certain hormone doesn't respond, even not as much as the wild-type?
  19. What does the enthalpy of formation indicate? A high enthalpy of formation would indicate...
    Enthalpy of formation is an indication of its instability. A high enthalpy of formation would indicate HIGH INSTABILITY. 

    This would be from torsional strain, for example. 
  20. What is the difference between a virus's lytic and lysogenic cycle?
    Lytic: causes host cell to burst rapidly from quickly manufactured "baby" viruses

    Lysogenic: Viral DNA integrates for a period of time wtihin the host cell's DNA, become "active" only after some environmental cue. 
  21. What are two examples of things that contribute to gas exchange in alveoli?
    1. Low partial pressure of O2 in pulmonary capillaries compared to inhaled air

    2. Presence of surfactant - lowers surface tension of the alveioli and facilitates gas exchange. 
  22. What are the 5 causes of microevolution?
    • 1. Genetic drift
    • 2. Mutations
    • 3. Gene flow
    • 4. Nonrandom mating
    • 5. Natural selection
  23. What is balancing rxns based on?
    The law of conservation of matter - it states that matter can neither be created nor destroyed.
  24. How does the size of a prokaryotic cell compare to the size of eukaryotic cell?
    Eukaryotic cells are 10x larger
  25. What are 4 methods to study cells? Which ones can be used for living cells?
    (1) Light microscopy - live cells; but dyes might kill them

    (2) Electron microscopy - uses beam of e-s instead of light, kills live specimens

    (3) Cell fractionation: cells whose cell membranes have been ruptured can be centrifuged to separate organelles by size/density

    (4)Freeze fracture - used to study cell membranes/organelles; frozen specimen; splits lipid bilayer to look at stuff. 
  26. Differences b/t prokaryotes & eukaryotes: 

    (1) Plasmids?
    (2) RNA processing
    (3) Location of transcription & translation
    • Plasmids: Yes; No.
    • RNA processing: Simple, no splicing; splicing 5'cap, poly A tail
    • Location of transcription & translation: simultaneously in cytosol; separately - transcription in nucleus & translation in cytosol.
  27. Differences b/t prokaryotes & eukaryotes: 

    (1) Cell division
    (2) Presence/Absence of cell wall
    (3) Cytoskeleton
    (1) Cell division: cell division & asexual reproduction via binary fission; cell division via mitosis & meisois - sexual reproduction.

    (2) Cell Wall: most have cell wall; plants and fungi have cell wall, not animals

    (3) Cytoskeleton: no; yes
  28. Differences b/t prokaryotes & eukaryotes: 

    (1) Flagella
    (2) Site of ATP synthesis
    (3) Site of respiration
    • (1) Flagella: differ
    • (2) Plasma membrane; mitochondria
    • (3) Cell membrane; large multicellular organisms require respiratory systems. 
  29. How can cells regulate the fluidity of its membrane? (2)
    By adjusting the number of unsaturated hydrocarbon tails (increasing these increases fluidity).

    Animal cells can also regulate by adjusting the amount of cholesterol in the membrane. 
  30. Define cytoplasm vs cytosol.
    Cytoplasm: Everything in plasma membrane except nucleus

    Cytosol: fluid component of the cytoplasm (aq). containing proteins, nutrients, etc. 
  31. Does the nucleolus have a membrane?
  32. Name the different parts of mitochondria's structure and their  relative pH level.

    • (1) Mitochondrial matrix - low H+ concentration
    • (2) Inner membrane - has electron carriers of ETC
    • (3) Intermembrane space - High H+ concentration

    Cristae - convolutions of the inner membrane. 
  33. What is the endosymbiotic hypothesis?
    Mitochondria are believed to have developed from early prokaryotic cells that began a symbiotic relationship with eukaryote ancestors (host cell provides nutrients and protection; mitchondria provides energy).

    Mitochondria has their own circular DNA and ribosomes and are capable of making proteins. Genome/ribosomes of mitochondria are more similar to pros than eus. 
  34. Is it possible for someone to have different mitochondrial DNA from their mother?
    No - the zygote receives all of its organelles from its mother, so all mitochondrial DNA is identical to mother's. 
  35. What are proteins destined from cytoplasm synthesized by? What about proteins destined for membrane/out of cell?

    How do pro ribosomes compare to eu ribosomes?
    • (1) free ribosomes
    • (2) RER ribosomes

    Pro ribosomes are smaller. 
  36. What is the difference between the Smooth ER and the RER?

    What is the interior of the ER called?
    Smooth ER has no ribosomes on surface, lipid synthesis, and detox

    Rough ER - has ribosomes on surface, protein synthesis. 

    Rough ER proteins: after synthesis --> lumen--> Parts of RER membrane bud off to form vesicles --> Golgi apparatus
  37. Do prokaryotes have lysosomes? What do lysosomes break down?

    Lysosomes break down proteins, carbohydrates, and nucleic acids. 
  38. What are lysosomes essential for in unicellular particles (1) and multicellular particles (2)?
    • (1) - food digestion
    • (2) - degradation of foreign material & damaged cells
  39. What are peroxisomes?

    3 Functions?
    Peroxisomes contain oxidative enzymes that catalyze reactions that produce hydrogen peroxide, break down fats, and used in liver to detox. 
  40. What would you expect to have more ribosomes: pancreatic cell or muscle cell?
    Pancreatic cell has more ribosomes because it has to make a ton of peptide hormones and enzymes. So if that's true, make sure you keep that in mind!!
  41. What is the cytoskeleton? What are 3 of its functions? What are 3 of its components? 
    Network of specialized protein that provide structure to the cell, cell movement, and movement of organelles within cell. 

    Microtubules, microfilaments, intermediate filaments
  42. What are the 3 components of the cytoskeleton? Describe each one:
    • 1. Microfilaments: 2 intertwined strainds of actin
    • 2. Intermediate filaments: structural support of cell
    • 3. Microtubules - hollow rods containing tubulin do all 3 of cytoskeleton's functions (maintenance of cell shape, cell movement, and movement of organelles within cell). 
  43. Where are centrioles found? Function?
    Found only in animal cells.  They are microtubule organizing centers that anchor microtubules during mitosis. 
  44. How do the motions of cilia vs flagella differ?

    Where is cilia found?
    Cilia - whiplike; flagella - wave-like

    Cilia lines respiratory tract to get dead cells, particulate matter, mucous, etc towards mouth for expulsion. 
  45. What neurotransmitter acts on cardiac muscle? 
    Ach (Acetylcholine) 
  46. Define immunoglobin
    Any protein in the serum/cell of immune system that acts as an antibody.
  47. When do organs appear in pregnancy?
    First trimester
  48. Will all drugs that affect humans affect monkeys the same way?
    Although we're pretty similar, there's never an absolute that every drug that works on human genome will work on the monkey genome. 
  49. Define the following:
    Genetic drift
    Gene flow
    Hybrid breakdown
    Genetic drift: chance variation in gene frequencies seen in one generation to the next. 

    Gene flow: movement of genes in and out of population, i.e. by migration

    Hybrid breakdown: produced by an interspecies mating two generations ago are fertile or inviable even though their hybrid parents were not.
  50. Define:

    Independent assortment - 
    Genetic linkage - 
    Recombination frequency - tendency of genes to recombine during meiosis; it's a function of physical distance b/t genes on the length of a chromosome. 
    Independent assortment: Allele pairs are separated randomly and independently during meiosis. 

    Genetic Linkage: Genes located closely enough on same chromosome that they're unlikely to get separated during a crossover event during meiosis. 

    Recombination frequency - tendency of genes to recombine during meiosis; it's a function of physical distance b/t genes on the length of a chromosome.

    Linked genes have a really, really low recombination frequency.
  51. If you have a weak acid on the reactant side and a very strong base and a weak acid on the other side, what should you expect the missing reactant to be?
    A strong base. 
  52. Will heptanol be soluble in aqueous NaOH? Why?
    No. Only 5>Carbons are soluble in aq solutions
  53. If albumin, a plasma protein, is infused into arterial blood, what changes would you expect to find in the capillaries?

    A. Increased permeability to albumin
    B. Decreased permeability to albumin
    C. Increased movement of water from the capillaries to the interstitial fluid
    D. Decreased movement of water from the capillaries to the interstitial fluid. 
    Decreased movement of water from capillaries to the interstitial fluid.

    This is because albumin is an osmotically active plasma protein and is one of the primary determinants of the blood's osmotic pressure. 
  54. Is albumin permeable to capillaries?
    No, it's not. 
  55. What's another term for impulse?
    Single action potential
  56. In a neuron, what happens as stimulus intensity increases? What can't it affect?
    Stimulus intensity would increase the frequency of the action potential (impulse). 

    It doesn't affect the duration or magnitude of the action potential nor does it affect the threshold membrane potential.
Card Set
Biological Sciences II