BIO 311C Study Guide - Fall 2018, Comprehensive Midterm Notes - Adenosine Triphosphate, Protein, Glucose
BIO 311C
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Biological molecules
Building blocks
• Polymer – long molecules composed of many similar building blocks
• Monomer – building blocks of polymers
• Fours life’s organic molecules – carbohydrates, proteins, nucleic acids
• Lipids – large molecules, not true polymer
• Dehydration reaction – synthesis of a polymer by releasing a water molecule
• Hydrolysis – breaking of polymer by adding a water molecule which breaks down to H
and OH and one attaches to one monomer, while the other attaches to the other monomer
Carbohydrates
• Sugars and polymers of sugars
• Monosaccharides = simple sugars (glucose, fructose, galactose)
o Contain CH2O
o Differ by placement of carbonyl group
• Disaccharides (2 sugars) – maltose, sucrose, lactose
o Dehydration reaction forms glycosidic linkage between monomers
• Carbohydrates macromolecules are polysaccharides (starch, glycogen, cellulose)
composed of many sugar building blocks
o Starch – used for energy storage in plant cells; stored in chloroplasts
o Glycogen – used for energy storage in animal cells (liver and muscles)
o Chitin – makes up exoskeleton of arthropods; provides structural support for cell
walls of fungi
Lipids
• Fats
o Glycerol and 3 fatty acids connected by ester linkages
o Saturated – all single bonds
o Unsaturated – 1 or more double bonds; results in bent shape of the fatty acid
▪ Usually liquid at room temperature because the bending prevents
formation of solid
o Hydrogenation – converts unsaturated fats to saturated fats by adding hydrogen
▪ Cis double bond – oleic acid – bent shape (hydrogens on the same side)
▪ Trans double bond – elaidic acid – straight (hydrogens opposite from each
other)
o Cholesterol
▪ Low-density lipoprotein (LDL) – carries cholesterol to cells for use in cell
membranes
▪ High-density lipoproteins (HDL) – collects excess cholesterol from blood
vessels and returns it to liver
▪ High LDL to HDL ration increases risk of developing arterial plaque,
which can lead to heart disease and heart attacks
▪ Consuming trans fats increases LDL to HDL ratio
• FDA says trans fats are bad for you
• Phospholipids
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o Phosphate group, glycerol and fatty acids
o One fatty acid is bent
o The head is hydrophilic, while the tail is hydrophobic
o Forms the phospholipid bilayer
• Steroids
o Most function as signaling hormones
o Cholesterol – regulating fluidity in animal cell membranes
Proteins
• Made up of amino acids; amine group – NH3+, carboxyl group – CO2-, C and H in the
middle and R group
• Peptide bond – covalent bond between C of carboxyl groups and N of amine group
o Releases H2O in dehydration reaction
• Structures of protein
o Primary – specific sequence of amino acids covalently bonded together to make a
polypeptide
o Secondary
▪ a helix formed by hydrogen bonding
▪ B pleated sheet formed by H-bonding
o Tertiary – folding of the polypeptide chain by weak bonds between R groups
o Quaternary – several polypeptide chains connected together
• Denaturation – a protein loses its 3-dimensional structure and becomes non-functional
when exposed to chemical conditions that disrupt non-covalent bonds
o Heat
o Strong acids
o Strong bases
o High salt concentration
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Document Summary
Proteins: made up of amino acids; amine group nh3. Spontaneous generation doesn"t exist all life comes from previous generation and there is a common ancestor of all life. Biosphere -> ecosystem ->communities -> populations -> organisms -> organs and organ systems -> tissues -> cells -> organelles -> molecules. Emergent properties properties which a complex system has, but which the individual members don"t have. Ex: water surface tension, which hydrogen and oxygen don"t exhibit by themselves. Electronegativity: the closer the two atoms in their electronegativities, the more equal their sharing of. Ionic bond transfer of electrons to form ions. Covalent bond sharing of a pair of electrons: link atoms to form molecules. Biologists think covalent bonds are stronger because water can break ionic bonds easily. + - present in amino acids, proteins and nucleic acids: sulfhydryl sh most reactive, present in proteins, phosphate po4, methyl ch3 present in lipids, proteins and nucleic acids.
