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Ch2 - Pt 2

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  • Triglycerides pt1

    called fats when solid and oils when liquid

    -composed of three fatty acids bonded to a glycerol molecule by dehydration synthesis

    -saturated fatty acids -linked via single colvalent bond, resulting in a molecule with the max # of H atoms

    • (linear molecules)

    • ex. animal fats, butter

  • Triglycerides pt2

    -unsaturated fatty acids- linked via double bonds, resulting in reduce H atoms

    • ex. plants oils, olive oil

    • transfat - modified unsaturated fat

    • omega-3 - "heart healthy"

  • Phospholipids

    make up most of the plasma in the cells membrane

    • modified trigylceride

  • Head and tail region of phospholipids

    head - Hydrophilic (likes water)

    tail- Hydrophobic (hates water)

  • Steroids

    consist of four interlocking ring structures

    -Most important steroid- cholesterol

  • Most important steroid

    cholesterol

    (made by the liver, important for cell plasma membrane, making vitamin D)

  • Proteins

    comprise 20-30% of cell mass

    • important for the structure of the cell, chemical (enzymes), contraction (muscles)

    • contain C, H, O, N and sometimes S and P

  • Polymers of amino acid monomers held together by

    Peptide bonds

  • Types of proteins and their functions PT 1

    • Structural- mechanical support (collogen)

    • Enzyme- catalysis. essential for virtually every biochemical reaction in the body

    • Transport- moving substances (in blood or across plasma membrane)

  • Types of proteins and their functions PT2

    • Contractile- movement (actin and myosin)

    • Communication- transmitting signals between cells (insulin)

    • Defensive- protect against diseases (antibodies)

  • Amino acids are attached by

    Peptide bonds

  • How many different amino acids are there?

    20

  • Two categories of protein shapes

    -Fibrous (structural) - stradnlike, water-insoluble, and stable, 3-D structures

    • ex. keratin, elastin, collagen

    -Globular (functional)- compact, spherical, water-soluble and sensitive to enviornmental changes, 3-D

    • ex. antibodies, hormones, molecular chaperones and enzymes

  • Characteristics of enzymes

    Most functional enzymes are referred to as holoenzymes

    • apoenzyme (protein portion)

    • cofactor (metal ion) or coenzyme (organic molecule, often a vitamin)

    • names usually end in -ase and oftern named for the reaction they catalyse

      • ex. hydrolases, oxidases

  • 3 steps in enzyme action:

    1. substrate binds to enzyme's active site, temporarily forming enzyme-substrate complex

    2. Complex undergoes rearrangement of substrate, resulting in final product

    3. Product is released from enzyme

  • Nucleic acids

    made of C, H, O, and P

    -largetst molecules in the body

    -DNA

    -made up of monomers called nucleotides

    • composed of nitrogen base, pentose sugar and a phosphate group

  • Two major classes of nucleic acids

    1. DNA

    2. RNA

  • DNA

    -holds the genetic blueprint

    -double stranded

    • twisted in a double helix

    -located in the nucleus

    -nucleotides contain a deoxyribose sugar, phosphate group and 1 of 4 nitrogen bases

    • Purines and Pyrimidines

    -follows complimentary base pairing

    • A always pairs with T

    • G always pairs with C

  • Purines

    -adenine (A)

    -guanine (G)

    bigger molecules

  • Pyrimidines

    -cytosine (C)

    -thymine (T)

    smaller molecules

  • RNA

    links DNA to protein synthesis

    -single stranded linear molecule, outside the nucleus

    -contains ribose sugar (not deoxyribose)

    -Thymine is replaced with Uracil

  • Three variations of RNA carry out the DNA orders for protein synthesis

    -Messenger RNA (mRNA)

    -Transfer RNA (tRNA)

    -Ribosomal RNA (rRNA)

  • ATP (adenosine triphosophate)

    chemical energy released when glucose is broken down

    -directly powers chemical reactions in cells

    • offers immediate, usable energy needed by body cells

    POWER FOR THE CELL

  • Structure of ATP

    adenine-containing RNA nucleotide with two additional phosphate groups

  • Adenine + Ribose

    is Adenosine

  • The loss of a phosphate group in ATP creates

    ADP (adenine diphosphate)

  • AMP (adenine monophosphate)

    -carrying messages from one place to the other in the cell

  • The loss of a second phosphate group converts

    ADP to AMP (adenine monophosphate)