Tamu Biol 111 Fletcher Final Test Questions And
Answers 100% Solved | Already Passed
explain how carbohydrates are formed from their respective subunits - ✔✔Formed from
monosaccharides, the simplest sugars that usually contain 3-7 carbons, generally have molecular
formula in the ratio CH2O, most names of sugars end in -ose
explain the structural and functional properties of carbohydrates - ✔✔-Structural properties: in
ratio CH2O, monosaccharides, disaccharides, polysaccharide
-Functional properties: storage (starch, consists entirely on glucose molecules, joined by 2 linkage types
alpha 1-4 and 1-6, major in plants, glycogen, all glucose, major in animals), structural (cellulose,
polymer of glucose, beta 1-4 linkages, plant cell wall, chitin, exoskeleton, nitrogen)
explain the benefits of carbohydrates - ✔✔provide energy to the body in the form of glucose
describe the 3 different classes of carbohydrates - ✔✔-monosaccharides: can be linear, but
mostly found as rings in aqueous solution
-disaccharides: consist of 2 monosaccharides, joined by glyosidic linkage
-polysaccharides: long chain of monosaccharides joined and identified by glyosidic linkages, may be
branched or unbranched
name important monosaccharides, disaccharides, and polysaccharides - ✔✔-
important monosaccharides: glucose, galactose, fructose
-important disaccharides: maltose (glucose+glucose, lactose(galactose+glucose),
sucrose (glucose+fructose)
-important polysaccharides: starch, glycogen, cellulose, chitin
explain how proteins are formed from their respective subunits - ✔✔formed by 1 or more
polypeptide, and a polypeptide is a polymer of amino acids linked by peptide bonds
,explain the structural and functional properties of proteins - ✔✔structural: 4 levels of structure, primary
(unique sequence of amino acids in a polypeptides), secondary (the folding/coiling of a polypeptide into
repeating configuration, alpha-helix (coil), beta pleated sheet (fold)), tertiary (overall unique 3D shape),
quaternary (2 or more polypeptides)
functional: regulatory, structural, protective, transport, enzymes, toxins, enzymes
(catabolic=breakdown, anabolic=build, catalytic=affect rate of reaction)
identify each of the 4 functional groups of an amino acid - ✔✔1) amino group (-NH2)
2) carboxyl group (-COOH)
3) central carbon atom
4) side chain (R-group)
explain the relationship between protein sequence and structure - ✔✔the sequence of amino
acids determines a proteins 3D structure, and ultimately its function
compare and contrast alpha helices and beta strands - ✔✔-alpha helices: formed by hydrogen
bond between the oxygen and carbonyl group and an amino acid 4 positions down the chain, coil
-beta strands: hydrogen bonding between atoms on the backbone of the polypeptide chain, fold
compare and contrast the concept of polarity in the context of chemical bonds and proteins -
✔✔polarity is determined by r group, when nonpolar the amino acid is rarely involved in protein binding
or active sites
explain how nucleic acids are formed from their respective subunits - ✔✔exist as polymers of known
as polynucleotides, which are made up of monomers known as nucleotides, nucleotides consist of a
sugar+base+phosphate group, nucleotides are bonded by phosphodiester bonds linked by the -OH on
the 3' end and the phosphate on the 5' end
explain the structural and functional properties of nucleic acids - ✔✔-Functional: DNA (carries
and stores genetic information), RNA (involved in protein synthesis)
-Structural: DNA (Double helix, CTAG), RNA (usually single stranded, CUAG)
,compare and contrast the concept of polarity in the context of nucleic acids and chemical bonds -
✔✔base pairs are joined due to hydorgen bonding
explain how lipids are formed from their respective subunits - ✔✔-Fats: 1 glycerol + (usually) 3
fatty acids, joined via ester linkage
-Waxes: long fatty acid chains, ester linked to long chain alcohols
-Phospholipids: have 2 fatty acids, and phosphate group rather than 3rd fatty acid
-Steroids: carbon skeleton consisting of 4 fused rings
explain the structural and functional properties of lipids - ✔✔-Structures are dominated by
nonpolar covalent bonds, including hydrocarbon regions
-Functions for long term energy stores, insulation from environment, building blocks for
some hormones, and important component for cellular membranes
compare and contrast the structure of a triglyceride with a phospholipid - ✔✔-Triglyceride: glycerol +
3 fatty acids (vary in double bond number, size, and length)
-Phospholipid: 2 fatty acids + phosphate group, hydrophilic head, hydrophobic tail
-Both: Attached at glycerol backbone
explain how the presence of double bonds or changes in the length of fatty acids affect the
physical properties of triglycerides - ✔✔-No double bonds=solid a room temperature (saturated)
-Double bonds=liquid at room temperature (unsaturated)
-1 double bond=monounsaturated
-2 or more double bonds=polyunsaturated
recall and define the terms hydrophilic and hydrophobic, relate these to and define amphipathic -
✔✔-Amphipathic is a molecule that is both hydrophilic and hydrophobic, has regions of both
sketch a cell membrane according to the fluid mosaic model - ✔✔fluid structure with a mosaic of
various proteins embedded in it
, indicate position and orientations of phospholipids, cholesterol and integral and peripheral membrane
proteins - ✔✔-Phospholipids: main fabric of membrane, arranged in a bilayer (phob=inward,
phil=outward/polar)
-Cholesterol: only in animals, in bilayer, acts as a buffer, between phospholipids, fluid when cold, not too
fluid when hot
-Integral proteins: integrated completely into bilayer, location and number determine how they
arrange within bilayer
-Peripheral: occur only on the surface of the bilayer
explain why membranes are asymmetrical - ✔✔inner surface differs from outer surface, interior is
not identical to the exterior
describe at least 3 different factors the affect membrane fluidity - ✔✔Size (smaller=easier), solubility
(soluble in lipid=easy), charge (if charged will rarely pass)
define diffusion, osmosis, amphipathic, and electrogenic - ✔✔-Diffusion: the tendency for any molecule to
spread out into the available space, substances move down concentration gradient, high to low
-Osmosis: the movement of water across a semipermeable membrane, from low to high
-Amphipathic: a molecule with areas of both hydrophilic and hydrophobic
-Electrogenic: producing a change in the electrical potential of a cell
describe the characteristics of molecules that can easily pass through a phospholipid bilayer -
✔✔small, simple, hydrophobic
explain what happens to an animal cell placed into hypotonic, isotonic, and hypertonic solutions -
✔✔-Hypotonic: cell will take in water/solution
-Isotonic: no net movement of water/solution
-Hypertonic: cell will lose water/solution
compare/contrast simple diffusion and facilitated diffusion - ✔✔-Simple=no energy
-Facilitated=uses transmembrane proteins