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Biology Keynote


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Biology Keynote

  1. 1. Biological Molecules Project Biology 12 by Coleman Everest
  2. 2. WATER • Earth’s ability to support life is based on the presence of Water as a solvent liquid water. It makes up approximately 60% of the human -Solvent for all polar molecules and ionic compounds, dissolves more body and 60% - 70% of all life forms. than any other liquid. -Acts as a “chemical wedge”; can break apart and form new bonds; facilitates many chemical reactions in biological systems in the human • A water molecule consists of two positively charged hydrogen atoms and one negatively charged oxygen body. atom. Water molecules are held together by weak attractive Water as a temperature regulator forces called hydrogen bonds. -Water temperature changes slowly; no drastic changes. -High boiling point (100 degrees Celsius) Water as a lubricant -A vital, natural lubricant. -Humans need water to produce the bodily fluids that allow us to blink, circulate blood, swallow, and do the horizontal monster mash. McGraw-Hill Companies • H2O is a polar molecule because the electrons are unevenly distributed meaning the hydrogen ends of the molecule have a slight positive negative charge and the oxygen end has a mild negative charge. This weak attraction is enough to create hydrogen bonds, but a whole water molecule is electrically neutral.
  3. 3. Acids, Bases, & Buffers Acids, bases and buffers all have important roles in the biological systems within the human body, with particular regard to maintaining chemical balance. Acids (substances with a pH lower than 7): essential to the digestive system. Hydrochloric Acid in our stomach helps us break down food particles so that nutrients can be extracted. Bases (with a pH greater than 7): blood must maintain a pH of about 7.35-7.45, (a slight base) in order for hemoglobin to be carried. Buffers are chemical combinations present throughout the systems of the human body that keep pH levels regular. Buffers resist changes in pH (from, for example, a poorly balanced diet) because they can take up hydrogen or hydroxide ions produced through the dissociation of water molecules. (see below) The scale used to measure the acidity or alkalinity of shows how dissociated substances is pH (0-14), 0 being very acidic and 14 hydrogen and being very alkali. Water is considered neutral at about 7. hydroxide ions can bond with other chemicals to form acids or bases.
  4. 4. Carbohydrates type structure examples All carbohydrates contain hydrogen, oxygen and carbon. The Glucose (pictured) Monosaccharide Ribose 3 main types of carbohydrates are monosaccharides, (Simple sugars) Fructose disaccharides and polysaccharides. (saccharide = sugar) The CnH2nOn Deoxyribose carbohydrates in one’s diet allow cells to produce energy. Sucrose/table Disaccharides sugar(pictured) Dehydration synthesis - A simple process by which Maltose monosaccharides become di- or polysaccharides: (Double sugars) Lactose Dehydration (removal of water) occurs when two carbohydrates are brought together to form a new carbohydrate. Water is left over as a by-product of the Starch synthesis, taking a hydrogen (H) and a hydroxide (OH) Polysaccharides Cellulose (pictured) from either carbohydrate. (Complex sugars) Glycogen Hydrolysis is the reverse of this process in which water is added to a compound in order to break it down. Cellulose: Found Starch: Storage only in plants - forms form of sugar in cell walls and gives plants. Helps maintain them their rigidity. structural integrity. Glycogen: Storage Contains inra- Contains double form of sugar in intermolecular bonds. animals. Contains hydrogens bonds. An double bonds. insoluble fiber. Dehydration Synthesis
  5. 5. Proteins Proteins are organic compounds made Amino Group Side chain Main Functions of up of one or several polypeptides. Proteins Amino acids (monomers) are •Source of energy bonded together in certain ways to • Builds / repairs body tissues form different proteins. There are a (muscle, etc.) total of 20 individual amino acids, all • Makes up enzymes & with a nitrogen-based amino group. hormones Peptide bonds, which form through • Maintains healthy hair, nails, dehydration reactions, link amino acids skin Carboxylic acid group. in a protein. Structure Primary: a sequence of amino acids held together by peptide bonds. Secondary: forms as a result of weak attractive forces between adjacent amino acids. Tertiary: globular proteins that hold their shape due to disulphide bonds between folded strands. Many enzymes have this structure. Quaternary: made of several polypeptides coming together to form a larger molecule. Hemoglobin has this structure and is made up of 4 polypeptides.
  6. 6. Nucleic Acids Nucleotides (a type of monomer) form polymers called nucleic acids. ATP: a single nucleotide which acts as a “mobile energy source” for all cells in the body. Deoxyribonucleic Acid DNA RNA Ribonucleic Acid The genetic material itself involved in using genetic information Double alpha helix structure Linear (single-stranded) structure The nucleotides are made The four types of The four types of up of a 5-carbon sugar, a nitrogenous bases in DNA nitrogenous bases in RNA phosphate, and a nitrogenous fall into two categories. fall into two categories. base. Purine bases Pyrimidine bases Purine bases Pyrimidine bases • Adenine (A) • Thymine (T) • Adenine (A) • Uracil (U) • Guanine (G) • Cytosine (C) • Guanine (G) • Cytosine (C) DNA has a double helix structure, consisting of a sugar- phosphate backbone (purple), held in helix formation by complimentary base pairings (T- A, C-G) and hydrogen bonding.
  7. 7. Lipids Oils, fats, waxes, steroids and phospholipids are all classified as lipids. Fats and oils (neutral fats) provide energy storage. They consist of 3 Steroids fatty acids attached to one glycerol “Circular fats”, steroids are structured very molecule and are known as differently than other lipids. Rather than Fatty acids are made triglycerides. Oils, liquid at room having a glycerol and 3 fatty acids, steroids of long hydrocarbon temperature, store energy in plants, consist of four carbon rings with other chains ending in an acid and fats, solid at room temperature do groups of atoms (OH-, etc.) added. Some Cholesterol group. the same in animals. Fats and oils are common steroids in the human body are not water soluble, and are stored in testosterone, estrogen, and cholesterol. Testosterone body tissue. There are two types Fatty acids of fatty acid. Glycerol Unsaturated Saturated • Has some double • single bonds between Phospholipids bonds between carbons, carbons allows for more A certain kind of fat that allowing for less hydrogens to be bonded, has a phosphate hydrogen atoms. Found saturating the carbons with group substituted for in plant oils. Hydrogens hydrogen. Found only in one of the three fatty can be added, making animal fats, which are solid at acids attached to the glycerol molecule. A them saturated. room temperature. phospholipid molecule consists of a polar (hydrophilic) “head” consisting of glycerol, nitrogen phosphate groups. and and non- polar (hydrophobic) “tail”, consisting of two fatty acids.
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  9. 9. Bibliography In Class Notes General & Human Biology: index.html Open School BC Biology 12 Course Resource: biology/bi12/mod1.html Chemical Compound Outline (Part I): Kimball's Biology Pages:http: // An On-Line Biology Book: BioBookTOC.html