Experimental Design
Observation: -Using your senses to explore life & collect data
Inference: -Logical interpretation based on background knowledge and experience.
Testable Question: All science research starts with a question that you can test.
Steps to Designing and Conducting an Experiment
Problem: -The question you are trying to answer
Hypothesis: -A possible explanation for an observation
*Must be testable
*Always should be an "IF, then" statement
Important Experiments throughout history:
Spontaneous Generation: -Life could arise from non-living matter ex. recipe for bees
Redi's experiment Pasteur’s Experiment:
Use a swan necked flask to settle the spontaneous generation argument
Important uses for today:
Pasteurization: Milk, wine, canned goods
Parts to an Experiment:
(The process of testing your hypothesis.)
Independent variable- -The one YOU change
Dependent variable- -The result of the change (the one you measure)
Control- -No treatment-your basis for comparison
Constants- -factors that are kept the same from one trial to the next
Analysis- -Record your results and find out if you have significant data--not just by chance
Conclusion- -Does your experiment support your hypothesis? If not, why?
Levels of your experiment: -the different treatments in your experiment. (or groups)
Repeated Trials: -times that you repeat each level of your experiment -the more trials the better
Characteristics of Living Things:
Living Things... are made up of units called cells reproduce are based on a universal genetic code (DNA) grow and develop obtain and use materials and energy (metabolism) respond to their environment (adapt) maintain a stable internal environment (homeostasis) as a group - change over time (a.k.a.-evolve)
Cellular Organization: -MUST have cells
-Must have cells organized into organs, tissues, etc.
Reproduction: -Must be able to produce offspring
-sexual: 2 cells/2 parents
-asexual: 1 parent
Heredity: -Must have genetic information to pass on to offspring (DNA)
Growth and Development: -Must have a life cycle of growth
-Development: may include a physical change ex.-puberty, metamorphosis
Metabolism: -Using energy for growth and development
-All the chemical reactions that buildup or breakdown materials for life.
Homeostasis: -Maintaining & regulating an internal environment
-respond & adapt
Examples:
Evolution: -Change over time as a species or group. Not an individual organism.
Carbon Compounds – Biochemistry
Terms you need to know:
Monomer -small subunit join together to form larger molecules
Polymers -large chains of molecules. Made of many pieces.
Name:
Function
Elements
Examples
Indicator
Carbohydrates
-energy source
-Monosaccharides: simple sugar
-Disaccharides: double sugar
-Polysaccharide: complex sugar, i.e.-starch
Carbon
Hydrogen
Oxygen
-Always 1: 2 : 1 ratio
Sugars and starches
-Benedict’s Solution: for simple sugars
-Iodine: for starches.
Lipids
-store energy & make biological membranes
-Hydrophobic-don’t mix with H2O
-Saturated : solid at room temp.
-Unsaturated: liquid at room temp.
Carbon
Hydrogen
Fats, Oils, waxes, cholesterol
-Brown paper bag test or paper towel test
Proteins
-control chemical reaction rates
-regulate cell processes
-help form bones and muscles
Nitrogen
Carbon
Hydrogen
Oxygen
Enzymes
Amino Acids
Insulin, hemoglobin
-Biuret Reagent: turns from dark blue to dark purple.
Nucleic Acids
-store and transmit hereditary information
-made of nucleotides
Hydrogen
Oxygen
Phosphorus
Carbon
Nitrogen
DNA
RNA
Chemical Reactions and Enzymes
Chemical Reaction: -Changes 1 set of chemicals into another set of chemicals.
What happens during a chemical reaction?
Reactants Products (bonds break) (new bonds form)
Enzymes: