Bio Ch 2

  1. What makes a substance an element and give example.
    When a substance can't be brokendown into different parts

    ex. gold, iron, mercury, carbon,helium
  2. What is an atomic number?
  3. What is atomic weight?
  4. What is an atom and what is it composed of?
    • smallest units that have all the chemical properties of the element
    • composed of electrons, protons, and nuetrons
  5. What is an isotope?
    Forms of an element with different numbers of neutrons

    they are unstable and decay
  6. Capabilites of rings of electrons
    • First ring is only capable of holding 2 electrons
    • Second ring holds up to 8 electrons
  7. Most often the number of protons ______ the number of neutrons.
  8. What is a half life?
    • the amount of time for 50% of isotope to decay
    • C14 half life=5730 years
  9. What is an ion?
    forms of an element with different numbers of electrons
  10. What is a molecule?
    two or more atoms linked together
  11. What is a chemical bond and what are the 3 kinds?
    attractive forces between atoms

    3 types- covalent, ionic, hydrogen
  12. What is a covalent bond?
    • physically sharing electron
    • shared pair of electrons
  13. What is an Ionic bond?
    • 2 ions (one positive, one negative) are attracted to each other
    • Sodium ion gives an electron to Chloride and becomes +1 and Chlorine is -1 and attract to each other
  14. What is a Hyrdogen bond?
    • Hyrdogen usually loses electron and becomes positive
    • they positive and negative ends attract
  15. Properties of Water and why does ice float?
    • sticky, clingy, has surface tension, takes lots of energy to heat water
    • ice floats because the molecules have spaces in between them and leaves trapped spaces and makes it lighter than liquid water
  16. What does a solvent do and give example.
    • A solvent dissolves other molecule
    • Water is a solvent
  17. What is a free radical?
    a single floating proton (charge of +1) with no electron
  18. What happens when there is a single electron in an electron ring?
    • it is usually plucked of
    • sodium becomes sodium hydroxide
  19. What does Hydrophilic mean and examples?
    • water loving
    • ex. sugar, salt
  20. What does hydrophobic mean and examples?
    • water fearing
    • ex. olive oil, baking grease, care grease, lipids, fats
  21. How do geckos cling to surfaces?
    they form hydrogen bond on their hands and feet with the objects they walk on
  22. What 4 biological molecules do all living things contain?
    carbohydrates, proteins, lipids, nucleic acids
  23. What are Carbohydrates?
    • sugars and starches
    • potatoes corns
    • simple sugars are the bases for carbohydrates
  24. protein forms and roles
    • beans, soy, meat, animals, nuts
    • structure, cell f(x), messengers, transport, communication
  25. what are polypeptides?
    • amino acid chains
    • there are 20 kinds
  26. lipids forms and roles
    • animals, lard, olive oil, sesame oil, coconut oil
    • energy storage, steroids, membranes
  27. lipids and cells
    create a double membrane around cells
  28. roles of nucleic acid
    • carry the "code" of life
    • DNA and RNA (they are made up of chains of nucleotides)
  29. Why are carbohydrates important?
    for cell recognition, energy storage, and cell structure
  30. Examples of monosaccharides.
    • glucose, fructose
    • glucose=what cells break down for energy
  31. Example of dissacharides.
    • sucrose (table sugar)
    • they are 2 simple sugars linked
    • formed by a condensation reaction and gives off water
  32. What is ATP?
    useable energy source that fuels cells
  33. DNA and RNA are each made up of only __ nucleotides.
  34. Cell Theory
  35. Plasma Membrane
    flexible and "fluid", protective covering around cell, studded with proteins
  36. selective permeabilty
    • membrane can allos some molecules to pass, others to be kept out
    • size, concentration, and solubilty determine how molecules pass through a membrane
  37. What is facilitated diffusion?
    pass through a protein "gate or channel" in the membrane
  38. What is active transport?
    uses energy to move molecule across a membrane (can work against a concentration gradient)
  39. Phagocytosis
    they are cells that are able to take in really large molecules, bacteria, viruses, cell debris, and large proteins
  40. the process of bringing into the cell is ___ and taking out
    endocytosis, exocytosis
  41. The nucleus...
    contains DNA in a nuclear envelope, proteins in envelope allow materials to pass in and out of nucleus, DNA code is converted to RNA code, RNA leaves nucleus
  42. Ribosome
    • in the cytoplasm “read” the RNA and make
    • proteins
  43. Endoplasmic Reticulum (ER)
    • makes and modifies proteins, called “rough” due to
    • ribsomes sticking out of
    • the membranes
  44. Golgi Apparatus
    further modifies proteins, ships proteins around cell and outside cell, like FedEx of cell
  45. Smooth ER
    lipid production cholesterol, sex hormones, Vitamin D synthesis
  46. Lysosomes
    "packets" of digestive enzymes, break down and recylce cell components, foreign materials
  47. Cyctoskeleton
    protein fibers within cell give structure and support
  48. Mitochondria
    energy production, breakdown sugars (glucose) and produce ATP, have their own DNA and ribosomes, it is ONLY inherited through egg (maternally, you can trace it back for lineage), is like MLGW provides energy
  49. Plastids (chloroplasts)
    use solar energy to synthesize sugars, cholorphyll-pigment gives plants green color
  50. vacuoles
    fluid-filled sacs, give cells "firmness"
  51. Cell Walls
    give cells structure, "cells" that Hooke saw, wood, cellulose (undigestable to us)
  52. How HIV takes over a cell
    • 1- needs to insert genetic material
    • 2- convert RNA into DNA
    • 3- get cell to make copies of DNA and to convert it to RNA
    • 4 - have cell make proteins from the RNA
    • 5 - Assemble proteins and new viruses
    • 6 - leave cell to infect new cells
Card Set
Bio Ch 2
Chapter 2 Intro to Biology Notes