Scientific Method Steps Observation Hypothesis Experiment Analysis and Conclusion If wrong form new hypothesis

Scientific Method Controlled experiment Tests effect of a single variable while keeping all other variables the same Any observed differences should be caused only by the single changed variable

Scientific Method Observations (qualitative and quantitative) Quantitative– involve numbers, counting, measuring objects. Qualitative– involve characteristics that cannot be easily measured or counted such as color or texture

Scientific Method Hypothesis– a possible explanation, a preliminary conclusion, or even an “educated” guess about some event in nature Theory– As evidence builds up, a particular hypothesis may become so well supported that scientists consider it a theory. Atomic theory

Chemistry Organic Compounds Carbohydrate- main source of energy for animals Monomer = monosaccharide (single suger) Polymer = Starch, Cellulose Protein- functional or structural Monomer = Amino Acid Polymer = Protein Nucleic Acid-controls inheritance Monomer = Nucleotide Polymer = DNA, RNA

Chemistry Enzymes Biological Catalyst Not used up during reaction Speeds up chemical reactions Lowers Activation energy (energy needed to get reaction started Not used up during reaction A specialized protein functional protein

Chemistry pH Measured on a scale of 1-14 Below 7 acid Above 7 base pH of 7 = neutral Speeds up chemical reactions Lowers Activation energy (energy needed to get reaction started

Chemistry Reactants and Products Reactants Products

Chemistry Solutions Solute- “stuff” that is dissolved Solvent –the liquid that does the dissolvin

Chemistry Chemical bonds– links that hold atoms together. Two main types Covalent bonds– formed by sharing electrons between two atoms Bond found in organic compounds

Chemistry Ionic bonds- formed by transfer of 1 more electrons from 1 atom to another Ion– (+) or (-) charged atom that results from gaining or losing electron

Cells Organelles

Nucleus- control center of cell. Contains DNA (genetic material) Nucleus- control center of cell. Contains DNA (genetic material). Found in eukaryotic cells.

Ribosome- organelle where proteins are made Ribosome- organelle where proteins are made. Free-floating and some on Endoplasmic reticulum

Golgi apparatus- Cells “post office”. Packages proteins

Endoplasmic reticulum- Cells transport system Endoplasmic reticulum- Cells transport system. Help make proteins (rough E.R.)

Lysosome- “clean-up” crew of cell Lysosome- “clean-up” crew of cell. Contains enzymes to break down old cell parts, digest food, etc.

Cell membrane- flexible, and semi-permeable membrane surrounding cell.

Cells Cell membrane- composed of lipid bi-layer (2 layers of lipids) Lipid layer also called phospholipids

Cells Semi-permeable- allows some things to pass through but not others Diffusion- movement from areas of high concentration to areas of low concentrations Osmosis- diffusion of water

Cells Active transport- takes energy (endocytosis and exocytosis) Passive transport- no energy required (diffusion and osmosis)

Cells Prokaryotes and Eukaryotes- Scientists divide cells Into two groups depending on whether they have a nucleus or not. 1. Prokaryotes-no nucleus Smaller and simpler than cells of eukaryotes Do have cytoplasm and cell membrane Example: Bacteria

Cells Eukaryotes- do contain nucleus and membrane bound organelles (includes plants, animals, fungi) Contain cytoplasm and cell membrane Contains organelles

Cells Homeostasis- maintain constant internal conditions (example: blood sugar levels, blood pressure, shivering/sweating)

Photosynthesis Equation Affected by: Energy from sunlight converts carbon dioxide and water into high energy sugar (glucose) Takes place in chloroplast (organelle) Affected by: 1. Light intensity 2. Amount of water 3. Temperature Autotroph- Can make their own food (plants) light 6CO2 + 6H2O C6H12O6 + 6O2

Cellular Respiration Heterotroph- can not make their own food. Need to eat something else to obtain energy (fungi, animals, most bacteria Equation Fermentation- still make energy when no oxygen present. Two types: alcoholic and lactic acid fermentation Mitochondria- where respiration takes place 6O2 + C6H12O6 6CO2 + 6H2O + Energy

Glycolysis → krebs cycle → electron transport Cellular Respiration Series of events: Glycolysis → krebs cycle → electron transport ENERGY

Cellular Respiration Photosynthesis Compared to Photosynthesis

Cell Division Cell cycle- series of event cell goes through as it grows and eventually divides. Interphase- When cell grows and develops, getting ready to divide again Mitosis- Division of cell nucleus (forms diploid (2N) cells) Cytokinesis- cell splits in two PMAT

Cell Division Results in 4 genetically different cells Meiosis- cell division forming sex cells (gametes) Results in 4 genetically different cells Gametes are N (haploid-half the number of chromosomes)

Cell Division Cell growth (cell gets bigger, volume increases faster than surface area) so has to divide

DNA, RNA, and Protein Synthesis Replication- DNA making DNA Transcription- DNA making RNA Translation- RNA making Proteins

DNA, RNA, and Protein Synthesis Sugar- deoxyribose Sugar-ribose Two stranded Single strand ATCG AUCG DNA-double helix 3 kinds of RNA

DNA, RNA, and Protein Synthesis Complementary bases DNA: C-G A-T RNA: C-G A-U

DNA, RNA, and Protein Synthesis Codon- three letter “word” on mRNA specifying a particular amino acid anticodon codon

Genetics homozygous same letters (TT or tt) heterozygous different letters (Tt) Genotype- the alleles (letters) i.e. Tt, TT, tt Phenotype- physical characteristics (Tall, short)

Genetics Gamete- sex cell (N) haploid. Zygote- fertilized egg Fertilization- process when sperm and egg join

Genetics Dominant / Recessive cross- one allele is dominant over another. I.e. T-tall (dominant) over t-short (recessive) TT X tt gametes T T All tall offspring Tt t t

Genetics Incomplete dominance- one allele is not completely dominant over another (RR-red crossed with WW-white yields all RW-pink flowers) RR X WW R R RW W W

Genetics Co-dominance- both alleles are dominant. RR-red hair, WW-white hair, RW-roan RR X WW R R RW W W

Genetics Dihybrid cross- Mendel’s two-factor experimental results were very close to 9:3:3:1 ratio predicted by punnett square. Proved that genes that segregate independently do not influence each other’s inheritance. Principle of Independent Assortment 9:3:3:1

Genetics Multiple Alleles- ABO blood type is an example. A and B or co-dominant.

Genetics Crossing over- when “legs” of chromosomes cross over each other during meiosis and exchange parts of themselves.

Genetics Non-disjunction- when chromosomes fail to separate during meiosis. Resulting in missing or extra chromosomes in gametes

Genetics “Code of Life”- Reading codons and the amino acids they code for Example: CGA UGC AAU Arg – Cys - Asn

Genetics Cloning- a member of a population of genetically identical cells produced from a single cell

Genetics Human Chromosomes- body cells contain 46 chromosomes (23 from sperm, 23 from egg. Join in diploid zygote) Karyotype- picture of chromosomes cut out from photographs and grouped together in pairs Sex chromosomes- two of 46- these determine sex of individual XX=female and XY=male autosomes- remaining 44 chromosomes

Genetics Egg cells contain a single X chromosome. Sperm cells contain either one X chromosome or one Y chromosome. Approximately half of the zygotes are XX (female) and half XY (male)