Study Guide
Independent variable: the manipulated variable. (Cause) DRY MIX
Dependent variable: the responding variable. (Effect)
Ex. Maria wants to test how heart rate will be effected by the amount of exercise a person does.
(Ind: heart rate , Dep: amount of exercise)
CHARTS GRAPHS Y axis
X / YInd. Variable / Dep. variable
Dep. variable
X axis
Ind. Variable
STEPS of the SCIENTIFIC METHOD
Ask a Question
Ex. How does fertilizer affect the growth rate of a plant
Do Background Research
Ex. What experiments have other scientists completed
Construct a Hypothesis
Ex. If fertilizer is added, the growth rate will increase
Hypothesis must be measurable and testable. (No love, luck, or feelings!)
Test Your Hypothesis by Doing an Experiment
Constant variables: Plant A, B, and C all receive the same amount of light and water
Test Groups: Plant A and Plant B receive different amounts of fertilizer.
Control Group: Plant C receives no fertilizer
Analyze Your Data and Draw a Conclusion
Did the results confirm (agree with) or refute (disprove) your hypothesis.
If the hypothesis is refuted, create a new hypothesis and begin again.
Communicate Your Results
If data supports the hypothesis scientists publish the results in a scientific journal (no blogs/Wikipedia)
Scientists use the scientific method to make testable explanations and predictions about the world. A scientist asks a question and develops an experiment, or set of experiments, to answer that question.
STEPS of the ENGINEER
Define the Problem
Do Background Research
Specify Requirements
Create Alternative Solutions
Choose the Best Solution
Do Development Work
Build a Prototype
Test and Redesign
Engineers create new things, such as products, websites, environments, and experiences, scientists study how nature works. Engineers use the engineering design process to create solutions to problems. An engineer identifies a specific need: Who need(s) what because why? And then, he or she creates a solution that meets the need.
LAB MATERIALS
Graduated cylinder: measures volume (of a liquid) in mL or Liters
Triple Beam Balance: measures mass in grams (g)
Pipette: small dropper, measures tiny amounts of liquid
Beaker or Test tubes: holds liquid for testing
Thermometer: measures temperature in Celsius or Fahrenheit
Hot Plate or Bunsen Burner: used to heat substances
pH paper: tests the pH of a liquid (whether it is an acid “acidity” or a base “alkalinity”)
Agar plate: a dish used to grow bacteria (also called a swipe plate)
Electrophoresis: a gel device that separates genes in DNA for genetic testing
Tongs: for folding hot test tubes or beakers
Forceps: tweezers for picking up very small items
LAB SAFETY RULES
Read the Procedure before beginning any experiment Do not point test tubes towards face
Do not touch broken glass (ask teacher) Long hair must be pulled back
Wear safety goggles, an apron, and gloves in lab. No dangling jewelry of clothes
Do not eat or drink in lab No open toed shoes
Do not sniff chemicals in lab, use the “wafting” method
If a person catches fire, use the fire blanket
If an object catches on fire, use the fire extinguisher
If you spill a chemical, call the teacher
Dispose of chemical in the waste container (not the sink)
THE ELEMENTS OF LIFE
ORGANIC: composed primarily of carbon (C), hydrogen (H), oxygen (O)
Of these elements, carbon is important because it can form millions of large, complex molecules essential to life. These large complex molecules are referred to as MACROMOLECULES
.
Carbohydrates: are composed primarily of carbon, hydrogen and oxygen and used primarily by living things as a source of energy and for structure.
Monosaccharides: The simplest carbohydrates.
Used directly by living cells to produce energy Ex. sugar : glucose C6H12O6.
Polysaccharides : complex carbs formed from monosaccharides. Ex. starch in potatoes or pasta.
allow living things to store energy for energy for future use.
Lipids: made up of carbon, hydrogen and oxygen and will not dissolve in water. Examples of lipids are fats, waxes, and sterols.
· used by living things for energy storage, contain even more energy than the carbohydrates.
· form an important part of cellular membranes
Fats are composed of fatty acid molecules bonded to glycerol molecules and may be saturated (such as the solid fats found in beef, butter,and cheese) or unsaturated (such as the oils found in olives, nuts, and fish).
Proteins: made of carbon, hydrogen, oxygen and nitrogen and serve as structural and regulatory substances.
· composed of smaller molecular units called amino acids.
· Ex. collagen that makes up tendons and cartilage, skin, hair, muscles
· Enzymes are proteins that increase the rate of a chemical reaction. Each enzyme acts on a particular target molecule or substrate. The enzyme has a region known as the active site that is able to chemically bond with the substrate molecule and allow chemical changes to occur in that substrate much faster than without the enzyme.
Nucleic Acids : DNA and RNA that contain the genetic information for living things. Involved in protein synthesis.