1 / 22

Chapter 2- Chemistry of Life Review

Chapter 2- Chemistry of Life Review. January 3rd. 2.1 Atoms, Ions, and Molecules. Atoms – smallest unit of matter Subatomic particles include: Protons (+) & Neutrons (o) in the nucleus Electrons (-) in the electron cloud Element – pure substance consisting of the same type of atom

tadhg
Download Presentation

Chapter 2- Chemistry of Life Review

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 2- Chemistry of Life Review January 3rd

  2. 2.1 Atoms, Ions, and Molecules • Atoms – smallest unit of matter • Subatomic particles include: • Protons (+) & Neutrons (o) in the nucleus • Electrons (-) in the electron cloud • Element – pure substance consisting of the same type of atom • Isotope– Element with a different number of neutrons

  3. Radioactive Isotopes– nuclei are unstable and break down at a constant rate over time. • Compounds – two or more elements combined in definite proportions • Chemical Bonds • Ionic Bonds– transfer of electrons between a metal and nonmetal • Creates an ion • Covalent Bond– sharing of electrons between two nonmetals • Creates a molecule

  4. Hydrogen Bonds • B/c of their partial + and – charges, polar water molecules can attract each other. • Hydrogen Bondsare not as strong as covalent or ionic bonds, but it can form multiple H bonds at a time.

  5. Cohesion – attraction b/w molecules of the same substance. • Causes water droplets to bead on smooth surfaces & allows insects to walk on ponds. • Adhesion– attraction b/w molecules of different substances. • Meniscuses form because of adhesion

  6. Capillary Action • Ability of a liquid to flow against gravity where liquid spontaneously rise in a narrow space such as between the hairs of a paint-brush, in a thin tube, in porous material such as paper. • can cause liquids to flow against the force of gravity

  7. Water as a Solvent • Molecules and ions cannot take place in chemical processes inside cells unless they dissolve in water. • Sugars and oxygen cannot be transported from one part of an organism to another unless dissolved in blood, plant sap, or other water based fluids.

  8. Acids and Bases • pH scale– indicates the concentration of H+ ions in a solution. • Ranges from 0 to 14, where 7 is neutral • pH < 7 is acidic • pH > 7 is basic • Acids– form H+ ions in a solution • Bases– form OH- ions in a solution

  9. Buffers • The pH of fluids within most cells in humans are kept b/w 6.5 and 7.5. • If the pH gets higher or lower it will effect the chemical reactions that take place within the cells. • pH control is important in maintaining homeostasis(equilibrium) • Buffers help control pH in the body. • Buffers are weak acids or bases that react with strong acids or bases to prevent sharp, sudden changes in pH.

  10. Role of Carbons • Why Carbon? • C has 4 valence e- & can join to form strong covalent bonds. • C can bond with other C atoms & form chains unlimited in length.

  11. Macromolecules – “giant molecules” made from thousands or even hundred of thousands smaller molecules. • Carbohydrates • Lipids • Proteins • Nucleic Acids

  12. 1. Carbohydrates- compounds made up of C, H and O atoms; used as a main source of energy • Monysaccharides- Glucose,Galactose(component of milk), Fructose(found in fruits) • Polysaccharides-Starch(chain of glucose molecules),Glycogen(animal starch, released from liver), Cellulose(plant starch)

  13. 2. Lipids- • - made from C and H atoms. • - not soluble; fats, oils, waxes • - lipids form when a glycerol molecule combines with fatty acids • Fatty acids are chains of C and H atoms • Functions: • stores energy • used in biological membranes & waterproof coverings.

  14. 3. Proteins- macromolecules that contain C, H and O • are most diverse macromolecule • contain monomers called amino acids • Amino acids are held together by peptide bonds to form the protein

  15. 4. Nucleic Acids • - are macromolecules containing H, O, N, C and P • - nucleic acids store & transmit hereditary or genetic information • - assembled from monomers called nucleotides • Nucleotides consist of 3 parts: • 5-carbon sugar • Phosphate group • Nitrogenous base

  16. 2 Main Groups of Nucleic Acids • Ribonucleic Acid (RNA) – contains the sugar “Ribose” • b. Deoxyribonucleic Acid (DNA) – contains “Deoxyribose”

  17. ATP • ATP is a chemical compound that cells would use to store energy or to release energy. • Activation Energy – Energy that is needed to start or “activate” a chemical reaction.

  18. 2 types of reactions in living things: • Exergonic Reactions - Reactions that RELEASE energy. • Often occurs spontaneously • Endergonic Reactions – Reactions that ABSORB energy • Will not occur w/out a source of energy • Reactants- substances changed • Products- substances made

  19. Enzymes • Enzymes– Proteins that act as biological catalyst. • Catalysts speed up chemical reactions • They work by lowering the activation energy. • They are very specific. • Enzyme names usually end in –ase. • Temperature and pH affect the enzyme activity

  20. The Enzyme-Substrate Complex http://highered.mcgraw-hill.com/sites/dl/free/0072495855/291136/enzymes.swf

More Related