Organization

2. Organization • Atom:Carbon • Molecule:Myoglobin (a protein) • Cells:Muscle Cell • Tissues: homogenous layer of cells. One being smooth muscle which is composed of layers of smooth muscle cells. • Organ: Different tissues working together to serve a similar function.Smooth muscle, epithelial and connective tissues…make up blood vessel (an organ) • System; blood vessels along w/ heart -Circulatory System (ORGAN SYSTEM LEVEL) • Organism: Cardiovascular System, Respiratory, Skeletal etc.

4. Atoms are electrically neutral Protons = Electrons Atomic number = number of protons Atomic mass = protons + neutrons

16. Planetary Models of Elements p+ represents protons, no represents neutrons

18. Chemically reactive—outer shell not full Chemically inert—full outer shell

21. Why Do Elements React? • Most elements react because they are highly UNSTABLE due to the fact that their outer electron shell or “valence shell” is not full. • Bonding, either by transference of electrons or sharing results in a full outer shell…and a new compound. • One column of elements ….The NOBLE gases, do not react..are inert , because their valence shells are already full.

22. Single Covalent Bond • One pair of electrons are shared

26. Anions and Cations • Anion • atom that gained electrons (net negative charge) • Cation • atom that lost an electron (net positive charge) • Ions with opposite charges are attracted to each other

30. Hydrogen Bonding in Water

31. Hydrogen Bonds • This is bond between molecules….. OR • Between different parts of one molecule • It occurs between covalently positively charged Hydrogen and negatively charged atom. • Important in many biological molecules ……like DNA!!!

32. Water • High Specific Heat- Loses and gains heats S-L-O-W-L-Y • High Surface Tension and Cohesion- Water molecules sticking together form a “film” or tension. • Universal Solvent- Dissolves polar or ionic molecules which are the most prevalent kind in living systems.

33. DNA and its H-Bonds

35. Acids, Bases and pH • An acid is proton donor (releases H+ ions) • A base is proton acceptor (accepts H+ ions) • pH = the concentration of H+ ions in solution • a pH of less than 7 is acidic solution • a pH of greater than 7 is basic solution • a pH of 7.0 is neutral pH

36. PURE Water is a neutral molecule; It has as many H+ as 0H- ions. pH = 7 • One unit in pH change = a 10 fold increase either way in H+ ion conc. • If pH goes up - then you have decrease H+ ion conc. Tenfold and you now are more basic (example.. pH 7 to pH 8 has 10x less H+)

37. 0 7 14 basic alkaline acid pH Negative logarithm of hydrogen ion concentration strongweakstrong

38. pH Scale

39. Acids and bases neutralize each other H+ from acids + [OH]- from bases H2O Buffers • prevent abrupt pH changes • act as H+ sponge

40. An Example of Homeostasis • Nearly all life chemistry occurs around pH 7…slightly over. Blood has pH between 7.3 and 7.5 and must be maintained as such! • When pH falls ACIDOSIS, TOO HIGH ALKALOSIS • BUFFERS: these are what MAINTAIN homeostasis of pH. ….we have buffer systems….Hemoglobin is a buffer.

41. Bicarbonate is an alkaline and a vital component of the pH buffering system of the body ,maintaining acid-base homeostasis. 70%-75% of CO2 in the body is converted into carbonic acid(H2CO3), which can quickly turn into bicarbonate (HCO3−). What are terms for too acidic? Too Alkaline?

45. Atoms are electrically neutral Protons = Electrons Atomic number = number of protons Atomic mass = protons + neutrons