SCIENCE QTR 4

• Biomolecules


  Carbohydrates, Lipids, Proteins, Nucleic Acid
• Carbohydrates


  Energy source
• Carbohydrates


  • Elements: CHO
  • Function: Energy source
  • Important group of biological molecules that includes sugars and starches
  • Contains CARBON, HYDROGEN, and OXYGEN only
  • General formula: Cn(H20)n
  • Basically carbon with water
  • When large pieces of carbohydrates break down, it turns into glucose
• Monosaccharides


  • Simplest carbohydrate and cannot be hydrolyzed (broken down due to water) to produce a smaller carbohydrate molecule
  • Simplest and cannot be further broken down
  • However, it can be added to
  • It's like the amino acid/nucleotide of protein/DNA (building block)
  • 1 chemical structure for sugar molecule
  • Elements: Carbon, Hydrogen, Oxygen
  • Contains between 3 and 7 carbon atoms
  • (CH2O): empirical formula of simple monosaccharides
  • Aldehydes or ketones
  • Aldoses contain an aldehyde (-CHO) functional group at one end. (e.g. glucose)
  • Ketoses contain a ketone (C=O) functional group usually at C#2 (e.g. fructose)
  • Can be in straight or ring structure
  • Long-chain structure - "Fischer Structure"
  • Ring Stricture = "Haworth projection"
• Hexose


  • Has 6 carbon atoms
  • Glucose, Fructose, and Galactose
  • All have the same chem. formula: C6H1206 , but they have different structures (ISOMERS)
  • Fructose is the sweetest and can be easily found on fruits and usually used for candies
  • Galactose is the least sweet
• Disaccharides


  • 1 monosaccharide + 1 monosaccharide = 1 disaccharide
  • 2 sugar molecule connected together
  • Glycosidic Acid
  • Bond/glue that connects the two monosaccharides together
  • Mawawalan ng water to unite the 2 monosaccharides due to the DEHYDRATION SYNTHESIS
  • From C6H12O6 to C12 H22O11 (combine two C6H12O6 , but remove H2O)
  • Dehydration synthesis (chemical process to combine 2 monosaccharides)
  • Another term of the process is condensation reaction
  • Adding water to disaccharides will allow the breakage of the bond
  • An enzyme removes an OH group (Hydroxyl) from Molecule A and a Hydrogen atom from Molecule B, forming H2O and a new covalent bond between the two molecules
  • Lactose, Maltose, Sucrose
  • Lactose is the enzyme that is found in stomach that digest dairy products (milk sugar)
  • Lactose breaks down dairy products via the rehydration process, which puts back the water which unbinds the monosaccharides, and thus producing LACTASE
  • Lactose Intolerance occurs when people LACK LACTOSE, therefore dairy products are not broken down
  • Sucrose is table sugar
  • Maltose is malt sugar
• Polysaccharides


  • Long chains of many monosaccharides joined together by glycosidic bonds
  • Starch, Glycogen, and Cellulose all contain glucose monosaccharides
• Starch


  • Plant storage polysaccharide
  • Energy = monosaccharide
  • Insoluble and forms starch granules inside many plant cells
  • Some plants store starch in their roots
  • Not a pure substance, but is a mixture of amylose and amylopectin
  • Amylase is the enzymes that can break down amylose and amylopectin into maltose but their dissolution is different because they have different structures
  • Amylose is straight and has less energy capability compared to Amylopectin
  • Amylopectin is branched and complex form, is the first to be dissolved as amylose can be stored. The more refined the food, the increase in amylopectin and sugar in the body
  • Starch is broken down into glucose and a disaccharide
• Glycogen


  • Similar in structure to Amylopectin
  • Made by animals as their storage, and is found mainly in muscle and liver
  • Because it is so highly branched, it can be mobilized (broken down to glucose for energy) very quickly
  • Stores more energy than starch
• Cellulose


  • Only found in plants, where it is the main component of plant cell walls
  • Alternate glucose molecules are inverted (diff to starch)
  • Not a plant storage for energy
  • Cannot be digested by most organisms due to the lack of cellulose enzyme
  • Forms straight chains
• Differences between Starch and Cellulose

  • Starch coils up to form granules
  • Cellulose creates straight chains
• Functions of Carbohydrates


  • Source of energy
  • Intermediate substance in respiration
  • Energy storage
  • Structure
  • Transport
  • Recognition
• Lipids


  • Elements: CHO
  • Function: Long term energy storage | Insulation | Protection
  • Fats or oils
  • Ex. butter, oil, cholesterol
  • Fats - solid in room temperature
  • Oils - liquid in room temperature
  • Building blocks: Fatty acids and glycerol
  • Lipase - enzyme that breaks down fats
  • Has a lot of carbon and hydrogen compared to oxygen
  • Insoluble in water but soluble in an organic solvent (e.g. ether, benzene, acetone, chloroform)
  • Excessive amount of lipids are bad for one's health
  • Connected via ester bonds
  • have NO TRUE MONOMER
• Functions of Lipids


  • Great at insulating (provides insulation of heat)
  • Great source of long term energy
  • Make up cell membrane and some hormones
  • Protection and source of energy
  • Digestion and absorption
• Saturated Fats


  • Single bonds
  • Have no double bonds between carbons in chain
  • Usually solid at room temp.
  • Stearic acid
  • Most Animal fats, butter, margarine, etc.
• Unsaturated Fats


  • Have one or more double bonds
  • Liquid at room temperature because they have lower melting points
  • Linoleic acid
  • Ex. found in vegetable oil
  • Easier to dissolve or break by body due to double bonds (unless it's trans fat) since they have bends that don't allow the blocks to be tightly stacked
  • Most common polyunsaturated fats contain the polyunsaturated fatty acids (PUFA's: oleic, linoleic, and linoleic acid.)
  • Considered "Healthier" because when stacked, due to their structure, would not clog the arteries
• Trans Fats


  • It's bad because it can lead to cancer due to its structure
  • Very sticky
• Classification of Lipids


  • Sterols/Steroids (Simple)
  • Triglycerides
  • Phospholipids
  • Waxes
  • Cholesterol
• Sterols/Steroids


  • Simple lipids have 4 fused Carbon rings
  • NO Fatty acids
  • Example: Cholesterol - most abundant steroids in animals
• Triglycerides


  • Composed of neutral lipids formed by esterification of 3 fatty acids
  • Esterification is the reaction between alcohol and carboxylic acid that results to the formation of an ester and water
• Phospholipids


  • Made with 2 fatty acids, glycerol and phosphate, and one simple organic molecule
  • Its head is hydrophilic (water-loving) and its long tail is hydrophobic
  • Major component of cell membrane
• Waxes


  • Water insoluble
  • Low melting point
  • Consist of long chain of fatty acid and a long chain of monohydroxyl group
• Cholesterol


  • Waxy, fat-like substance made in the liver and travels throughout the bloodstream
  • Body needs Cholesterol to make new cells
  • Too much of it can cause HEART DISEASES as it can build up and block the veins in the heart
• Types of Cholesterol


  • LDL (Low-Density Lipoproteins) - Called Bad cholesterol, can build up in our arteries, which causes them to narrow, leads to heart diseases and stroke
  • HDL (High-density Lipoproteins) - Good cholesterol, takes LDL away from the arteries and back to the liver, where it is broken down and processed
• Triglycerides


  • Most common type of fat
  • Store excess fat from your diet
  • Should be kept low
• Proteins


  • Elements: CHON
  • Building Block: Amino Acids
  • A line of amino acids is read and processed by an enzyme for it to function as a protein
  • Function: Enzymes, Structure, Movement
  • Held together by peptide bonds
  • Examples: Antibodies, Enzymes, Receptors (for movement), Hormones, Genes
• Nucleic Acids


  • Elements: CHONP
  • Building Block: Nucleotides
  • Composed of 5-carbon sugar (pentose)
  • Deoxyribose/DNA (double helix structure)
  • Ribose/RNA
  • Phosphate group
  • Nitrogenous Base (A, T/U, C, G)
  • Function: Genetic information, Protein Synthesis (DNA -> RNA)
• General Properties of Gas

  • NO definite shape and volume
  • Diffuse readily
  • Compress readily
  • Lowest density
• Kinetic Molecular Theory


  • The volume taken by gas molecules is assumed to be negligible relative to the volume of the container
  • Takes up the shape of the container (has no definite shape nor volume)
  • There is no force of attraction between and among gas molecules
  • Gas molecules cannot attract other molecules
  • Gas molecules are in a CONSTANT, RANDOM, and LINEAR motion. No energy is lost when they collide because it has PERFECTLY ELASTIC COLLISION
  • The average KE of gas molecules is the same for all gasses at the same T, and its value is directly proportional to Kelvin
• Fundamental Properties of Gases

  • Volume (V) = liters (L)
  • Pressure (P) = atmosphere (1 atm = 1.015 x 105 N/m2)
  • Temperature (T) = kelvin ( K = C* celsius + 273)
  • Number of atoms or molecules, m = mole ( 1 mol = 6.022 x 10 23 atoms or molecules)
• • @STP means Standard temperature and Pressure
  • Standard pressure: 1 atm
  • Standard temperature = 273 K
• Boyle's Law


  • Pressure and volume are inversely related at constant temperature
  • PV = K
  • As one goes up, the other goes down
  • FORMULA: P1 V1 = P2 V2
  • Was discovered by Robert Boyle, "Father of Modern Chemistry"
  • Marshmallow in a Bell Jar experiment: As the pressure increased, the marshmallow SHRANK. As the pressure decreased, the marshmallow ENLARGED
• Charles' Law


  • Volume of a gas varies directly with the temperature at constant pressure
  • V = KT
  • FORMULA: V1/T1 = V2/ T2
  • Was discovered by Jacques-Alexandre Charles
  • Experiment with a balloon
• Gay-Lussac's Law


  • At constant volume, pressure and absolute temperature are DIRECTLY RELATED
  • P = kT
  • FORMULA: P1/T1 = P2/ T2
  • Was discovered by Joseph-Louis Gay-Lussac