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Chemistry of Life…continued

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Presentation on theme: "Chemistry of Life…continued"— Presentation transcript:

1 Chemistry of Life…continued

2 Mixture and Solutions When elements combine to form a compound, the elements no longer have their original properties. A mixture is a combination of substance in which the individual components retain their properties. Ex: Sand and sugar

3 A solution is mixture in which one or more substances (solute) are distributed evenly in another substance (solvent) Ex: Kool-aid *The concentration of solute is important to organisms A suspension is a mixture of water and nondissolved materials

4 Acids and Bases Chemical reactions can occur only when conditions are right; they depend on the pH of the environment pH is a measure of how acid or basic (alkaline) a solution is A scale with values ranging from 0 to 14 is used to measure pH

5 H+ OH- ACID is any substance that forms hydrogen ions (H+) in water.
Ex: HCl (H+) and (Cl-) has a pH of below 7 BASE is any substance that forms hydroxide ions (OH-) in water. Ex: NaOH (Na+) & (OH-) has a pH above 7

6 Buffers=dissolved compounds that control pH in the body;
they are weak acids or bases that can react with strong acids or bases to prevent sharp sudden changes in pH.

7 Importance of Acids and Bases to Biological Systems
Chemical reactions in organisms depend on the pH of the environment Ex: Pepsidase is an enzyme that works best in the acidic human stomach

8 Organism A__________ Organism B 4.5 10.5 0-8 6.5-14 Certain organisms require a certain pH environment for optimum (best) growth

9 Life Substances Organic compounds are derived from living things and contain Carbon, must have Carbon and Hydrogen to be organic Inorganic compounds are derived from nonliving things (ex: Water, Carbon Dioxide)

10 Carbon compounds: easily form 4 covalent bonds to create chains , rings, or branches

11 Polymerization: when a large compound (polymer) is produced from smaller compounds (monomers) as the smaller compounds are joined together. Macromolecules: large polymers

12 Hydrolysis to split, water is added
Condensation Reaction (dehydration synthesis) to make or build, water is produced Hydrolysis to split, water is added

13 3. 4 Major Organic Compounds
Carbohydrates Lipids Proteins Nucleic Acids

14 Carbohydrates Composed of C (Carbon), Hydrogen (H), Oxygen (O) in approximate ratio 1:2:1

15 GLUCOSE-Produced by plants through photosynthesis
Monosaccharide: single (simple) sugar Molecular formula for all 3: C6H12O6 GLUCOSE-Produced by plants through photosynthesis FRUCTOSE-found in fruits GALACTOSE-found in milk

16 Disaccharides formed by 2 sugars C12H22O11
Sucrose = glucose + Fructose Maltose = glucose + Glucose Lactose = glucose + Galactose

17 Polysaccharides formed by more than 2 sugars
Starch-storage for plants Glycogen-storage for animals (liver) Cellulose-cell wall of plants Chitin=cell wall of fungi

18 What makes them different from one another is the arrangement of the individual atoms (structural formulas) Isomers – compounds that differ in structure but nor in molecular composition

19 Synthesis of Dissachharides
Glucose Fructose Sucrose Water + + + + C12H22O6 + H2O C6H12O6 C6H12O6 + * Dehydration synthesis-water is squeezed out

20 Hydrolysis of Disaccharide
Sucrose Water Glucose Fructose + + + + C6H12O6 C6H12O6 C12H22O6 H2O + + * Hydrolysis-water is added

21 Lipids: Fatty Compounds
Made of C, H, O w/ a greater # in C:H atoms and a smaller # of O atoms than carbohydrates (No uniform Ratio) Ex: fats, oils, waxes (do Not dissolve in water)

22 Many common lipids are constructed of a unit of:
Glycerol (3-Carbon Alcohol) combined by dehydration synthesis 3 fatty acids-hydrocarbon chain with an Carboxyl Group -COOH

23 3 fatty acids-hydrocarbon chain with an Carboxyl Group -COOH
Hydrophilic End (water loving-carboxyl end that is polar) Hydrophobic End (water fearing-hydrocarbon end that is nonpolar)

24 Functions: forms much of cell membrane to serve as a barrier between the inside and outside of the cell – energy storage for cells Ex: waxes, triglycerides

25 Proteins: Organic Compounds made of C, H, O, N
Polymer made of amino acids (monomers); organisms have thousands of proteins

26 Amino Acids: 20 different kinds that form proteins-has 5 Groups:
Central C atom Single H atom Carboxyl Group (COOH) Amine Group (NH2) R Group (repeating CH2 + CH2 of different lengths)

27 Dipeptide: 2 amino acids bound together covalently by condensation reaction (a molecule of H2O is lost)-held together by peptide bonds b) a) c) d) e) Amino acid Amino acid Water Dipeptide

28 A long chain of amino acids held together by peptide bonds
Polypeptide: A long chain of amino acids held together by peptide bonds Ex of Proteins: Insulin (hormone), hemoglobin, and enzymes

29 2 important types of nucleic acids are DNA and RNA
Nucleic Acids: complex organic molecules that store important information in the cell 2 important types of nucleic acids are DNA and RNA DNA (deoxyribonucleic acid): stores essential info for almost all cell activities-including cell division RNA (ribonucleic acid): stores and transfers info for proteins

30 Phosphate Group Five-Carbon Sugar Nitrogen Base (ring)
Nucleotides: monomers that make up both DNA & RNA-made up of 3 main components: Phosphate Group Five-Carbon Sugar Nitrogen Base (ring)


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