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BASIC CHEMISTRY Chapter 2 – Advanced Human Anatomy
Introduction Chemistry is the branch of science that considers the composition of matter and how this composition changes. Chemistry is essential for understanding anatomy and physiology because body structures and functions result from chemical changes within cells.
Structure of Matter is anything that has mass (weight) and takes up space. Matter is found in various forms: gases, liquids, and solids Elements make up all matter. Elements are composed of tiny particles called atoms. Atoms are the smallest unit of matter
Atomic Structure Nucleus is the central portion of the atom which contains neutrons (neutral) and protons (positive). Electrons: found outside the nucleus in energy shells (orbitals); negative charge.
Drawing atoms Atomic number is the number of protons in an element. The number of protons in the nucleus of an atom equal the number of electrons in its shells. Atoms are neutral Electron shells or orbitals: 1 st shell can hold a max of 2 electrons 2 nd – 6 th shells can hold a max of 8 electrons
Drawing atoms continued… Atomic mass = the number of protons plus neutrons. Therefore… atomic mass minus atomic number equals # of neutrons.
Atoms want Stability The defining characteristic of stable elements is the maximum number of electrons in its valence (outer) shell. Unstable elements achieve stability by gaining, losing, or sharing electrons in their energy levels or shells.
Bond Types Ionic bonds occur between a metal and nonmetals when they transfer electrons forming ions. Atoms that gain or lose electrons and become electrically charged Charged atoms = ions Covalent bond between two nonmetals they share electrons. Hydrogen Bonds: electromagnetic attractive interaction between polar molecules, in which hydrogen is bound to a highly electronegative atom, such as nitrogen or oxygen.
Molecules and Compounds A molecule is formed when two or more atoms combine. If atoms of different elements combine, the resulting structure can also be called a compound. Examples: Baking soda, sugar Molecular formula represents the numbers and types of atoms in a molecule. Examples… H 2 O & C 6 H 12 O 6
Chemical Reactions Synthesis when two or more atoms or reactants bond to form a new, more complex structure. Synthesis requires energy and is important to the growth of body parts. Decomposition the opposite of synthesis Single Replacement: A single free element replaces or is substituted for one of the elements in a compound Double Replacement: reaction type can be viewed as an "exchange of A + B AB AB A + B AB + C AC + B AB + CD AD + CB
Reaction Speed Catalysts affect the speed of a reaction Many reactions occur to slowly to sustain life Not consumed by the reaction. Biological catalysts? Enzymes!
Acids and Bases p. H scale ranges from 0 to 14. It indicates how the concentration of H+ in a substance Acids have p. H less than 7 More H+ than OH- Neutral p. H equal to 7 Bases have p. H greater than 7 More OH- than H+
ORGANIC AND INORGANIC COMPOUNDS Day 2 – Basic Chemistry (Chapter 2)
Organic vs. Inorganic 2 types of chemicals Organic must contain carbon and hydrogen but may contain other elements as well. (C 6 H 12 O 6) Inorganic all the other compounds that do NOT contain carbon-hydrogen bonds; (H 20)
Inorganic Compounds Water: plays an important role in dissolving solid substances, moving chemicals around the body, and absorbing and moving heat Oxygen: Releases energy from glucose and other nutrients. Most abundant compound in cells and is a solvent in which chemical reactions occur. Polar molecule This energy drives metabolism! Carbon Dioxide: inorganic substances that is a metabolic waste product, exhaled from the lungs. Salts: provide a variety of ions that metabolic processes require.
Organic Compounds Carbohydrates Lipids Proteins Nucleic acids
Carbohydrates Supply most of the energy needed by cells Composed of what 3 elements? Building blocks = sugars Carbon, Hydrogen, Oxygen Monosaccharides (simple sugars) Disaccharides are two sugars joined together Polysaccharides, such as starch, are built of many sugars. Humans synthesize the complex carbohydrate called glycogen.
Type of condensation reaction in which monomers (monosaccharides) join together into polymers while losing a water molecule This process is carried out by losing (-OH) from one of the monomers and (H) from another.
Lipids = concentrated energy molecules Building block (monomer) = fatty acid Not soluble in water Common Categories Fats Oils Waxes
energy storage very concentrated 2 x the energy as carbohydrates! cell membrane cushion Organs Nerve cells insulates body Whale blubber!
Saturated vs. Unsaturated Saturated = single carbon bond, maximum # of hydrogen bonds Unsaturated = carbon-carbon double bond Polyunsaturated = more than one carbon-carbon double bond
Fat molecule is not a polymer, just a big “fat” molecule.
Proteins have many of functions in the body---as structural materials, as energy sources, as certain hormones, as receptors on cell membranes, as antibodies, and as enzymes Building blocks of proteins are the amino acids (20) Give their identity by their R-Group Link up to form chains – these chains become proteins!
Amino Acids are composed of: Amino group Carboxyl group Hydrogen R-group
Amino Acids 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Alanine Glutamic acid Leucine Serine Arginine Glutamine Lysine Threonine Asparagine Glycine Methionine 12. Tryptophan 13. Aspartic acid 14. Histidine 15. Phenylalanine 16. Tyrosine 17. Cysteine 18. Isoleucine 19. Proline 20. Valine (NOTE: the 8 essential amino acids are in blue. These cannot be synthesized by the human body and must be obtained from food)
Protein Shapes Proteins have complex shapes held together by hydrogen bonds. (their many shapes changes their functions) Their complex shapes are known as conformations Protein shapes can be altered by p. H, temperature, radiation, or chemicals. When the H bonds break this is called denaturing
Enzymes Some chemical reactions are too slow or have activation energies way too high so we need a…. : speeds up reaction and lowers the activation energy : biological catalysts! Enzymes are PROTEINS. Found in cells
Enzyme-Substrate Complex Enzymes provide a site where reactants can be brought together to react Reactants in an enzyme reaction are called substrates Enzyme and the substrate fit together a bit like a puzzle! Active site: place where substrate and enzyme bind Once the reaction is over, products are released and the enzyme is free to start the process over again
Induced-Fit Model Hypothesis Induced-Fit model: This model proposes that the initial interaction between enzyme and substrate is relatively weak, but that these weak interactions rapidly cause shape changes in the enzyme that strengthen binding Enzyme changes shape during the reaction
Nucleic Acids Nucleic acids form genes and take part in protein synthesis. Contain the elements C, H, O, N, P The building blocks are nucleotides. Two major types: DNA (with deoxyribose) and RNA (with ribose).
DNA & RNA Deoxyribonucleic acid: DNA (deoxyribonucleic acid) stores the molecular code in genes. How many strands does it have? Ribonucleic acid: RNA (ribonucleic acid) functions in protein synthesis. How many strands does it have?
Nucleotides Building block of nucleic acids – Nucleotides consist of 3 parts: Five carbon sugar Phosphate group Nitrogenous base N base sugar phosphate