Unit 1: Homeostasis & the Cell

1. Unit 1: Homeostasis & the Cell

2. Homeostasis The body’s ability to maintain a stable internal (inside) environment, while the external (outside) environment is changing. Inside Body Temperature: 98.6° F Outside Temperature: 25° F Outside Temperature: 95° F

3. Levels of Organization • Cells • Tissues • Organs • Organ Systems

4. The modern system of classification has 8 levels: Domain Kingdom Phylum Class Order Family Genus Species

5. Helpful way to remember the 8 levels • Dumb kids playing catch on freeways get squashed • Or…make up your own… • D K P C O F G S

7. Cell Membrane The cell membrane is flexibleand allows a unicellular organism to move

8. Functions of Plasma Membrane • Protective barrier • Regulate transport in & out of cell (selectively permeable) • Allow cell recognition • Provide anchoring sites for filaments of cytoskeleton

9. Structure of the Cell Membrane

10. Phospholipids Make up the cell membrane Contains 2 fatty acid chains that are nonpolar Head is polar & contains a Phosphate group

11. Cell Membrane Polar heads are hydrophilic“water loving” Nonpolar tails are hydrophobic“water fearing” Makes membrane “Selective” in what crosses

12. Types of Transport Across Cell Membranes

13. Simple Diffusion • Requires NO energy • Molecules move from area of HIGH to LOW concentration

14. DIFFUSION Diffusion is a PASSIVE process which means no energy is used to make the molecules move.

15. Osmosis Diffusion across a membrane • Diffusion of water across a membrane • Moves from HIGH Concentration to a LOW concentration Semipermeable membrane

16. Cell in Isotonic Solution 10% NaCL90% H2O ENVIRONMENT CELL NO NET MOVEMENT 10% NaCL 90% H2O What is the direction of water movement? equilibrium The cell is at _______________.

17. Cell in Hypotonic Solution 10% NaCL90% H2O CELL 20% NaCL 80% H2O What is the direction of water movement?

18. Cell in Hypertonic Solution 15% NaCL85% H2O ENVIRONMENT CELL 5% NaCL 95% H2O What is the direction of water movement?

19. Passive Transport • Simple Diffusion • Doesn’t require energy • Moves high to low concentration • Example: Oxygen diffusing in or carbon dioxide diffusing out.

20. Passive Transport • Facilitated diffusion • Doesn’t require energy • Uses transport proteins to move high to low concentration • Examples: Glucose or amino acids moving from blood into a cell.

21. Active Transport • Requires energy or ATP • Moves materials from LOW to HIGH concentration • AGAINST concentration gradient

22. Moving the “Big Stuff” Exocytosis- moving things out. Molecules are moved out of the cell by vesicles that fuse with the plasma membrane. This is how many hormones are secreted and how nerve cells communicate with one another.

23. Moving the “Big Stuff” Large molecules move materials into the cell by one of three forms of endocytosis.

24. Unit 2: Biochemistry

25. Molecules and Compounds • Ionic Bonding • Non-metal and metal • Electrons are transferred from one atom to another (high ΔEN) • Goal is to have a complete valence shell • Covalent Bonding • Two non-metals • Electrons are shared between two atoms

26. Molecules and Compounds • Polar vs. Nonpolar Covalent Bonds • Electrons are shared, but they may not be shared equally • Polar molecules are hydrophilic (water loving) • Non-polar are hydrophobic (water fearing) • Amphipathic • Polar and non-polar ends

27. Properties of Water Covalent bonding Polar covalent bond – unequal sharing of electrons A great example of a molecule with polar covalent bonds is water. Why is water considered polar? What is a partial positive and partial negative charge?

28. Properties of Water Covalent bonding vs. Hydrogen bonding Hydrogen Bond Covalent Bond

29. Properties of Water Cohesion, Adhesion and Surface Tension cohesion = water attracted to other water molecules because of polar properties adhesion = water attracted to other materials surface tension = water is pulled together creating the smallest surface area possible

30. Properties of Water In order to raise the temperature of water, the average molecular speed has to increase. It takes much more energy to raise the temperature of water compared to other solvents because hydrogen bonds hold the water molecules together! Water has a high heat capacity. “The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.” High Heat Capacity

31. Types of Biological Molecules 1. Many biological molecules are polymers • polymers are long chains or branching chains based on repeating subunits (monomers) • example: proteins (the polymer) are made from amino acids (the monomers) • example: nucleic acids (the polymer) are made from nucleotides (the monomers

32. Types of Biological Molecules 2. The four major classes of biologically important organic molecules are: carbohydrates lipids proteins or polypeptides (and related compounds) nucleic acids (and related compounds)

33. Carbohydrates Carbohydrates include sugars, starches, and cellulose carbohydrates contain only the elements carbon, hydrogen, and oxygen

34. Carbohydrates • glycogen is the main storage carbohydrate of animals • similar to starch, but very highly branched and more water-soluble • is NOT stored in an organelle; mostly found in liver and muscle cells

35. Lipids IV. lipids are fats and fat-like substances • lipids are a heterogeneous group of compounds defined by solubility, not structure • roles of lipids include serving as membrane structural components, as signaling molecules, and as energy storage molecules • major classes of lipids that you need to know are triacylglycerols (fats), phospholipids, and steroids

36. Proteins V. proteins are macromolecules that are polymers formed from amino acids monomers • proteins have great structural diversity and perform many roles • roles include enzyme catalysis, defense, transport, structure/support, motion, regulation; protein structure determines protein function • proteins are polymers made of amino acid monomers linked together by peptide bonds

37. Protein Denaturation • denaturation is unfolding of a protein, disrupting of structure • changes in temperature, pH, or exposure to various chemicals can cause denaturation • denatured proteins typically cannot perform their normal biological function • denaturation is generally irreversible

38. Nucleic Acids VI. nucleic acids transmit hereditary information by determining what proteins a cell makes • two classes of nucleic acids found in cells: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) • DNA carries the genetic information cells use to make proteins • RNA functions in protein synthesis according to mechanisms

39. DNA vs. RNA • DNA typically contains the purines adenine (A) and guanine (G), and the pyrimidines cytosine (C) and thymine (T) • RNA typically contains the purines adenine (A) and guanine (G), and the pyrimidines cytosine (C) and uracil (U)

40. Lipids • Two general categories of fatty acids: • Unsaturated fatty acids • Liquid at room temp. • Oils, plant fats (generally) • Saturated fatty acids • Solid at room temp. • Butter, animal fats (generally)

41. What Are Enzymes? • Most enzymes are Proteins (tertiary and quaternary structures) • Act as Catalyst to accelerate a reaction • Not permanently changed in the process

42. Unit 3: Digestion & Nutrition

43. Unit 4: Circulatory System

44. Cardiovascular System • Pathway of blood through the heart • Deoxygenated Blood • superior vena cava, inferior vena cava, right atrium, right ventrical, pulmonary artery • Blood received oxygen from lungs • Oxygenated Blood • Pulmonary vein, left atrium, left ventrical, aorta

46. Cardiovascular System • Pulmonary arteries • Carry blood away from the heart to the lungs • Carry deoxygenated blood • Pulmonary Veins • Carry oxygenated blood from heart to the lungs

47. Cardiovascular System • Heart Beat • Systole • Contraction of heart muscles • Diastole • Relaxation of heart muscles • Heart beat • Number of times heart beats per minute

48. Cardiovascular System • Blood Pressure • Pressure your blood exerts against your blood vessel walls as your heart pumps • Systolic • Pressure peak of heart beat • Higher number • Diastolic • Pressure when heart is resting • Lower number • Both in mm Hg

49. Organs of the Respiratory System Main organs of the upper and lower respiratory system

50. Glottis – triangular slit that opens during breathing/talking, and closes during swallowing Epiglottis – flaplike structure that stands upright, allows air to enter larynx, during swallowing it presses downward and prevents food from entering air passages