The Characteristics of Life: Cells, Metabolism, Reproduction, Homeostasis, Heredity, Responsiveness, Growth

1. 1. The Characteristics of Life • 1. Cell - smallest unit capable of life functions (basic unit of life) • 2.Metabolism - the sum of all chemical reactions, metabolism refers to a living organism's ability to consume and use energy (from food or from the sun) • 3. Reproduction - the process by which organisms make more of their own kind • 4. Homeostasis - maintaining stable internal conditions (biological balance) • 5. Heredity - the passing of traits from parents to offspring. The unit of heredity is the GENE - which codes for a trait. When a gene changes, it is called a MUTATION • 6. Responsiveness: reaction to select stimuli, physiologically and/or behaviorally • 7. Growth: conversion of materials from the environment into components of organism

2. Sweating allows the body to cool, maintaining normal body temperatures # 2 EX: • Homeostasis means “same state” and it is the process of keeping the internal body environment in a normal state. Insulin Injections allow diabetics to maintain normal glucose levels

3. #3 Scientific Method Scientific Method is presented 20 different ways in 20 different books. Don’t get hung up on it! Remember that a Hypothesis is a Prediction!

4. #4 • A useful hypothesis is a testable statement which includes a prediction.

5. #6 Scholarly Journals: best choice • Scholarly journals are often key resources for academic research. • Journal articles are "peer-reviewed," meaning their content is reviewed and approved by experts in the discipline. • Watch out, encyclopedias may have worked in middle school, but they no longer should be you best reference!

6. #7 Control Group • Control group • the group that is not changed; “normal conditions” • used for comparison

7. # 8 Experimental Variables • Independent variable • experimenter changes (“I” change) • Dependent Variable • is measured or observed • changes due to the independent variable The only way to eliminate experimenter bias

8. #9. Mr. Brodowski wanted to test how effective note cards were on helping students prepare for tests. He divided his class into two groups. He told GroupA to make note cards each day for the next ten days, and Group B did not make note cards. He found that Group A scored 10 points higher on the test than Group B. • Identify: • Independent Variable Dependent Variable • Control Group • Experimental Group

9. #9 (cont.) Bart thinks that mice exposed to microwaves will become stronger. He decided to do this as an experiment in his mother’s microwave. He placed 10 mice in the microwave for half a minute. He then compared the “waved” mice to a group of “non-waved” mice. To test his hypothesis, the mice would have to move a heavy block of wood that covered their food. Bart found that 8 “waved” mice and 8 “non-waved” mice could move the block of wood. • Identify: • Control Group ______________ • Independent Variable ___________ • Dependent Variable ______________

10. Lipids • 1.Fats • 2. Oils • 3. Waxes • 4.Cholesterals • 5. Steroids Proteins 1. Pigments – Provide skin color and protection 2. Structure – Cell structure 3. Keratin – Nail and Hair 4. Carriers – Hemoglobin 5. Enzymes #12 Carbohydrates Polysaccharide: many sugar units 1. starch = plant storage (bread, potatoes) 2. glycogen = animal storage (beef muscle) 3. cellulose = Plant structure (lettuce, corn) Nucleic Acids DNA – Deoxyribonucleic acids - DNA is our genetic code - It contains the information for our cells RNA – Ribonucleic acids - RNA reads the DNA and provides instruction

11. #13 • The monomer or building block of carbohydrates is monosaccharides • Protein’s building blocks (monomers) of amino acids • The Building Blocks (monomers) of nucleic acids are nucleutides • Lipids: Triglycerides:composed of 1 glycerol and 3 fatty acids.

12. #14 • Protein/Amino acids are composed of Carbon, Hydrogen, Oxygen and Nitrogen (CHON) • Carbohydrates/monosaccharides Composed of Carbon, Hydrogen and Oxygen (CHO) 1:2:1 C6H12O6 • Nucleic Acids (DNA, RNA) are composed of Carbon, Hydrogen, Oxygen, Nitrogen and Phosphate (CHONP)

13. BTW • KNOW THIS PICTURE A lipid by any other name is a glycerol connected to 3 fatty acids

14. And this picture • Nucleotide • Building block of Nucleic acid

15. HO H H2O HO H HO H # 15 Hydrolysis • Separates monomers by “adding water” • Used to separate macromolecules

16. HO H HO H H2O HO H #16 Dehydration Synthesis • Also called “condensation reaction” • Forms polymers by combining monomers by “removing water”. • Used to form macromolecules.

17. #17 • Ice is less dense as a solid, so ice floats • Cohesion: attraction between particles of the same substance Ex. Surface Tension • Adhesion : attraction between two different substances. • Ex. Capillary action

18. #17 cont. Salt in water will dissolve because it is polar, thus the universal solvent name • Polar water molecules act like magnets and attract each other • Water is often said to be the universal solvent, because it can dissolve many substances (think Kool-Aid)

19. #18 How do enzymes Work? Enzymes work by weakening bonds which lowers activation energy

20. #19 Enzymes • Most enzymes are Proteins • Are Reusable • End in –ase -Sucrase -Lactase -Maltase

21. # 20 Factors Affecting Enzyme Activity (denature= Stopping its function) • Temperature • pH • Cofactors & Coenzymes • Inhibitors Denatured by pH or temp change: substrate no longer fits

22. #21 Enzyme-Substrate Complex • Enzymesare substances present in the cell in small amounts which speed up or catalyze chemical reactions. Enzymes speed up the rate of chemical reactions because they lower the energy of activation, the energy that must be supplied in order for molecules to react with one another. Enzymes lower the energy of activation by forming an enzyme-substrate complex. BTW, Change the pH or temperature and this enzyme might not work (denatured)

23. #21 Enzymes (another view in case the flash didn’t work for the last one)

24. #22 CELL SHAPE • 1. Cells come in a variety of Shapes. • 2. Notice the neurons on the wall, the basic cell of our Nervous System.  This diversity of form reflects a diversity of function. • 3.  Most Cells have a Specific Shape. • 4.  THE SHAPE OF A CELL DEPENDS ON IT'S FUNCTION. • 5.  Cells of the Nervous System that carry information from your toes to your brain are long and threadlike. • 6.  Blood Cells are shaped like round disk that can squeeze through tiny blood vessels.

25. #23 The Cell Theory consist of THREE Principles: A. All living things are composed of one or more cells.     B. Cells are the basic units of structure and function in an organism.    C. Cells come only from reproduction of existing cells. (remember the Redi experiment)

26. #24 • It is harder for a large cell to pass materials in and out of the membrane, and to move materials through the cell • Bottom Line:You want a large surface area to volume ratio, which mean a small cell! Look how long it would take for stuff to get to the nucleus. NOT GOOD!! The Good The UGLY The Bad

27. #25 What are the Simplest Levels? • Atom • Molecule • Organelle • Cell • Tissue • Organ • System

28. #26 Cell Membrane • The Cell Membrane Functions like a GATE, Controlling what ENTERS and LEAVES the Cell • This "Selectively Permeable" Membrane regulates what passes into and out of the cell

29. #26 FLUID MOSAIC MODEL FLUID- because individual phospholipids and proteins can move around freely within the layer, like it’s a liquid. MOSAIC- because of the pattern produced by the scattered protein molecules when the membrane is viewed from above. Maybe TMI, but discuss.

30. #26 cont. • Hydrophilic (water-loving) polar heads of the phospholipid molecules lie on the outward-facing surfaces of the plasma membrane. • Hydrophobic (water-fearing) nonpolar tails extend to the interior of the plasma membrane. Yea, I know it is a cheesy picture. It is not like I get these from Sports Illustrated!

31. #27 Organelles (yes, there are more to know) I know it is a little kiddy, but look at that man in the overalls, ain’t he the cutest thing you ever seen!

32. #28 Prokaryotes (Bacteria) • Pro (before) Karyon (kernel) • No nuclear membrane • Lack membrane bound organelles • Simple and often small

33. #28 Eukaryotes (animal) • Eu (true) Karyon (kernel) • Membrane bound organelles • More complex and often bigger • Membrane bound nucleus

34. #31 Plant Cell • Eukaryotes for they have membrane bound organelles and a true nucleus • Have cell wall, central vacuum and chloroplast • Lack flagella, cilia, lysosomes and centrioles

35. #30 • Glycoprotein acts as flags/ recognition sites for cells. Also called marker proteins.

36. #32 Endosymbiosis • Process by which prokaryotes gave rise to the first eukaryotic cells • Cells are living together within cells • Mitochondria and Chloroplast • Lynn Margulis discovered

37. #33 Isotonic Solution Hypotonic Solution Hypertonic Solution NO NET MOVEMENT OF Both in and out equally IN OUT

38. # 34 Solubility • Materials that are soluble in lipids can pass through the cell membrane easily

39. # 35 Semipermeable Membrane Small molecules and larger hydrophobic molecules move through easily. e.g. O2, CO2, H2O

40. #35 Semipermeable Membrane Ions, hydrophilic molecules larger than water, and large molecules such as proteins do not move through the membrane on their own.

41. #36 Osmosis in Red Blood Cells Isotonic Same Hypertonic Shrinks Hypotonic Swells

42. hypotonic hypertonic isotonic hypertonic isotonic hypotonic #36 cont

43. #37 Simple Diffusion • Requires NO energy • Molecules move from area of HIGH to LOW concentration

44. #37 Osmosis Osmosis – diffusion of water through a membrane

45. Facilitated diffusion requires a carrier protein but uses NO ENERGY (With C.G.) #38

46. Active transport requires a carrier protein and ENERGY (Against C.G.) ENERGY #38 cont

47. BTW Endocytosis: large particle ENter the cell

48. More BTW Exocytosis large particles EXit the cell

49. #39 Overview of Cellular Respiration • 1. Process that releases energy by breaking down food molecules in presence of oxygen Carried out by both plants and animals!

50. #39 Cont. Aerobic versus Anaerobic respiration Aerobic Anaerobic Occurs in cytoplasm Occurs without oxygen or when oxygen is not available Produces only 2 ATP Called fermentation!! In yeast cells and human muscle cells • Occurs in Mitochondria • Requires Oxygen • Produces MOST ATP; either 36 or 38