Biology 102. Instructor: Nate Miller Phone: Office : White Oak Hall 220

Transcription

1 Biology 102 Instructor: Nate Miller Phone: Office : White Oak Hall 220

2 Name Goals Favorite Scientist Note Card Science education background. Something interesting (hobbies, favorite joke, celebrity you most resemble, etc.) Anything

3 Goals Gain a better understanding of biological systems 1. Cell structure and function 2. Cell division and inheritance 3. Evolutionary processes Understand the scientific method (scientific inquiry)

4 Extra Credit Read a chapter of a popular biology book and write a one page summary of it. Digital format 2%

5 Suggestions Genome Diversity of life The beak of the finch The advance of the fungi Darwin s dream pond The botany of desire The Immortal Life of Henrietta Lacks

6 Biology 102 Class Structure Grading: Percentage of final grade: 10 Labs, drop the lowest one = 10% Other in class Activities = 15% Online Homework = 10% 2 midterm exams = 40% Final Comprehensive exam = 25%

7 Expectations Respect towards instructor and fellow students I respect you Interaction and participation with instructor and fellow students Sincere interest and enthusiasm for learning Effort

8 Policies No Cell Phones Lap tops are OK for class use Emergency situations can have exceptions

9 Policies Grading Scheme: % A 80 89% B 70 79% C 60 69% D 59.9 % and below F

10 Biology: the study of life

11 What is Life? Definition

12 What is Life? Growth Reproduction Adaptation Metabolism Cellular

13 Cells

14 Tree of Life BACTERIA ARCHAEA EUKARYA animals fungi plants protists FIRST CELLS

15 Observation The car won't start. The scientific Question Why won't the car start? method Hypothesis The car won't start because the battery is dead. Propose a new hypothesis. Prediction IF the hypothesis is correct, THEN the car will start if the battery is replaced. Experiment or Observation The battery is replaced. If the car doesn t start: If the car starts: Conclusion The dead battery hypothesis is supported.

16 Observation: Flies swarm around meat left in the open; maggots appear on the meat. Question: Where do maggots on the meat come from? The experiments of Francesco Redi Hypothesis: Flies produce the maggots. Prediction: Experiment: IF the hypothesis is correct, THEN keeping the flies away from the meat will prevent the appearance of maggots. Obtain identical pieces of meat and two identical jars Place meat in each jar Leave the jar uncovered Experimental variable: gauze prevents the entry of flies Cover the jar with gauze Leave exposed for several days Controlled variables: time, temperature, place Leave covered for several days Flies swarm around and maggots appear Results Flies are kept from the meat; no maggots appear Control situation Experimental situation Conclusion: The experiment supports the hypothesis that flies are the source of maggots and that spontaneous generation of maggots does not occur.

17 Luck and observation A Petri dish contains solid growth medium Bacteria grow in a pattern created by streaking A substance from the mold diffuses outward and inhibits the growth of nearby bacteria A colony of the mold Penicillium

18 Chemistry Atoms Protons Neutrons Electrons

19 e electron shell p (a) Hydrogen (H) atomic nucleus

20 e p p n n e (b) Helium (He)

21 2e 4e 6e 8e 5e 2e 2e 2e 8e 8e 2e 6p 8p 15p 20p 6n 8n 16n 20n Carbon (C) Oxygen (O) Phosphorus (P) Calcium (Ca) C O P Ca

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23 1 An electron absorbs energy 2 The energy boosts the electron to a higher-energy shell 3 The electron drops back into lower-energy shell, releasing energy as light heat energy light

24 Bonds Covalent Polar Nonplolar Ionic Hydrogen

25 Hydrogen gas (H 2 ) Same charge on both nuclei _ + _ + (hydrogens: uncharged) Electrons spend equal time near each nucleus (a) Nonpolar covalent bonding in hydrogen gas (H 2 )

26 Water (oxygen: slightly negative) ( ) _ Larger positive charge 8p + 8n _ Electrons spend more time near the larger nucleus + + (hydrogens: slightly positive) (+) (+) Smaller positive charge

27 Macromolecules

28 Macromolecules Carbohydrates Lipids Proteins Nucleic acids

29 Monosaccharides fructose galactose

30 Dehydration synthesis dehydration synthesis

31 Hydrolysis hydrolysis

32 Disaccharide glucose fructose sucrose dehydration synthesis

33 Starch polysaccharide starch grains (a) Potato cells (b) A starch molecule (c) Detail of a starch molecule

34 Potato cells starch grains (a) Potato cells

35 Cellulose

36 Wood is mostly cellulose and lignin

37 Lignin

38 Chitin

39 Lipids

40 Triglyceride glycerol fatty acids triglyceride

41 A fat and an oil

42 Phospholipids variable functional group phosphate group polar head (hydrophilic) glycerol backbone fatty acid tails (hydrophobic)

43 Steroids

44 Protein

45 Amino acid structure variable group amino group carboxylic acid group hydrogen

46 Protein synthesis amino acid dehydration amino acid synthesis peptide water amino group carboxylic acid group amino group peptide bond

47 Amino acid diversity glutamic acid (glu) aspartic acid (asp) phenylalanine (phe) leucine (leu) (a) Hydrophilic functional groups (b) Hydrophobic functional groups cysteine (cys) (c) Sulfur-containing functional group

48 Sulfur-containing functional group

49 The four levels of protein structure (a) Primary structure: The sequence of amino acids linked by peptide bonds leu (b) Secondary structure: Usually maintained by hydrogen bonds, which shape this helix val heme group lys lys gly his ala hydrogen bond lys val lys pro helix (c) Tertiary structure: Folding of the helix results from hydrogen bonds with surrounding water molecules and disulfide bridges between cysteine amino acids (d) Quaternary structure: Individual polypeptides are linked to one another by hydrogen bonds or disulfide bridges

50 Nucleic Acids Adenine Thymine (Uracil) Guanine Cytosine

51 Five-carbon monosaccharides ribose 3 2 deoxyribose Note missing oxygen atom

52 Deoxyribose nucleotide phosphate sugar base

53 The energy-carrier molecule adenosine triphosphate (ATP)

54 Deoxyribonucleic acid (DNA) hydrogen bond

55 What is a cell? Smallest unit w/ property of life Single-celled organisms Make up multicellular organisms

56 The Cell Theory 1. All organisms composed of cells 2. Smallest unit of life 3. Division of preexisting cell 4. Possess heritable material (DNA)

57 Cytoplasm Aqueous material cytoplasm plasma membrane

58 nucleus nuclear envelope nuclear pore chromatin (DNA) nucleolus microfilaments cytoplasmic fluid microtubules (cytoskeleton) flagellum basal body rough endoplasmic reticulum vesicle intermediate filaments (cytoskeleton) centriole ribosomes on rough ER cytoplasm Golgi apparatus polyribosome smooth endoplasmic reticulum mitochondrion plasma membrane free ribosome lysosome exocytosis of material from the cell

59 nucleus microtubules (cytoskeleton) cell walls of adjoining plant cells nuclear envelope nuclear pore chromatin nucleolus ribosomes intermediate filaments (cytoskeleton) chloroplast rough endoplasmic reticulum cytoplasm lysosome smooth endoplasmic reticulum central vacuole mitochondrion cell wall plasmodesmata cytoplasmic fluid plastid free ribosome Golgi apparatus vesicle plasma membrane

60 Prokaryotic Cells Capsule plasma membrane Fig 4.4 Cell wall outside the plasma membrane cytoplasm, with ribosomes DNA in nucleoid region

61 Eukaryotic cell NUCLEUS Fig 4.4 CYTOPLASM w/ RIBOSOMES PLASMA MEMBRANE

62 How big are cells? Most cells can be seen with light microscope

63 Cell Membranes Fluid Composed of phospholipids, proteins, etc. Semipermeable

64 Triglyceride glycerol fatty acids triglyceride

65 A fat and an oil

66 Phospholipids variable functional group phosphate group polar head (hydrophilic) glycerol backbone fatty acid tails (hydrophobic)

67 phospholipid extracellular fluid (watery environment) hydrophilic heads bilayer hydrophobic tails hydrophilic heads cytoplasm (watery environment)

68 Kinks increase fluidity more fluid less fluid

69 Steroids

70 Endomembrane System lysosome Food digestion Damaged component

71 Exocytosis

72 Found in plants Sugar production Photosynthesis Chloroplast Chloroplast Central Vacuole Storage of water and waste

73 Mitochondria Energy producer of cell (ATP) Two membranes allows for gradient formation Where cellular respiration occurs Mitochondria Outer membrane Inner membrane outer compartment inner compartment

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75 Cells and cell membranes Prokaryotic vs. Eukaryotic Nucleus and other organelles

76 extracellular fluid (outside) carbohydrate glycoprotein A phospholipid bilayer helps to isolate the cell's contents Proteins help the cell communicate with its environment cholesterol membrane protein channel protein cytoskeleton cytoplasm (inside)

77 Diffusion of a dye in water 1 A drop of dye is placed in water 2 Dye molecules diffuse into the water; water molecules diffuse into the dye 3 Both dye molecules and water molecules are evenly dispersed drop of dye water molecule

78 Diffusion and Osmosis Molecules move from high density to low density (diffusion) Diffusion across a membrane is Osmosis Some molecules can t cross the cell membrane without active transport.

79 Types of diffusion through the plasma membrane Step 1 (extracellular fluid) O 2 Cl water glucose phospholipid bilayer (cytoplasm) channel protein aquaporin carrier protein (a) Simple diffusion through the phospholipid bilayer (b) Facilitated diffusion through channel proteins (c) Osmosis through aquaporins or the phospholipid bilayer (d) Facilitated diffusion through carrier proteins

80 The effect of solute concentration on osmosis No net flow of water Water flows out; the balloon shrinks Water flows in; the balloon expands (a) A balloon in an isotonic solution (b) A balloon in a hypertonic solution (c) A balloon in a hypotonic solution

81 The effects of osmosis on red blood cells

82 DNA vs. RNA DNA uses deoxyribose and RNA uses ribose RNA has the nucleotide urical instead of thymine DNA is much more stable than RNA

83 DNA to RNA DNA is the blueprint The code for individual genes gets copied to RNA RNA is used as a template to make protein

84 RNA to Protein Ribosomes The code for individual genes gets copied to RNA RNA is used as a template to make protein

85 nucleus nuclear envelope nuclear pore chromatin (DNA) nucleolus microfilaments cytoplasmic fluid microtubules (cytoskeleton) flagellum basal body rough endoplasmic reticulum vesicle intermediate filaments (cytoskeleton) centriole ribosomes on rough ER cytoplasm Golgi apparatus polyribosome smooth endoplasmic reticulum mitochondrion plasma membrane free ribosome lysosome exocytosis of material from the cell

86 Prokaryotic Cells Capsule plasma membrane Fig 4.4 Cell wall outside the plasma membrane cytoplasm, with ribosomes DNA in nucleoid region

87 nucleus microtubules (cytoskeleton) cell walls of adjoining plant cells nuclear envelope nuclear pore chromatin nucleolus ribosomes intermediate filaments (cytoskeleton) chloroplast rough endoplasmic reticulum cytoplasm lysosome smooth endoplasmic reticulum central vacuole mitochondrion cell wall plasmodesmata cytoplasmic fluid plastid free ribosome Golgi apparatus vesicle plasma membrane

88 Turgur pressure in plant cells cytoplasm central vacuole When water is plentiful, it fills the central vacuole, pushes the cytoplasm against the cell wall, and helps maintain the cell's shape Water pressure supports the leaves of this impatiens plant (a) Turgor pressure provides support cell wall plasma membrane When water is scarce, the central vacuole shrinks and the cell wall is unsupported Deprived of the support from water, the plant wilts (b) Loss of turgor pressure causes the plant to wilt