Do Now – January 23, What are the starting materials and products of cellular respiration? 2.In an experiment, what are controlled variables? What is another term for these? 3.Why is it important to have multiple trials in an experiment?

Today’s Objective SWBAT – Design an experiment using CR concepts

Cellular Respiration and Exercise Pre-Lab Ms. Klinkhachorn January 23, 2012

Get Out A Sheet of Paper You’ll be working in groups of 2 Pick your partner wisely

Design Your Own Experiment You will need: 1.A purpose question 2.A hypothesis 3.A set of SPECIFIC, SCIENTIFIC procedures 4.A data table

Background Information Bromothymol blue is an indicator for carbon dioxide – it will change color if CO 2 is added to it. Bromothymol blue solution changes color from dark blue to light green

Safety Bromothymol is a CHEMICAL. You need to be careful while handling it. – Do NOT ingest this material. – Do NOT get it on your skin (it stains) Reminder: If you are chewing gum, eating, or drinking in the lab, you will lose points

Cellular Respiration Equation Oxygen + Glucose   Water + Carbon Dioxide + ATP Chemical formulas: Oxygen = O 2 Glucose = sugar = C 6 H 12 O 6 Water = H 2 O Carbon Dioxide = CO 2

Control Groups Different from controlled variables! This is the condition of the experiment that you do nothing to – It allows you to make a comparison and to show how changing the condition affects the dependent variable

Examples of Control Groups What is the effect of light on plant growth? – A plant with regular light What is the effect of the amount of fertilizer on plant growth? – A plant with no fertilizer

Lab Materials Bromothymol Blue Drinking Straw Stop Watch Beaker Water Pipette

Write Your Purpose Question You have been asked to figure out how exercise affects cellular respiration. Be specific: – Independent Variable? – Dependent Variable?

Write Your Hypothesis Answer your purpose question and give a reason (based on your background knowledge) why you think this will happen.

Experimental Guidelines Procedures must: – Be written in numbered steps – Include specific, reproducible information Example: In a 200 mL beaker, add 100 mL of water – Be as controlled as possible Example: same person exercises every time – Include at least 4 different conditions (including a control group) with 3 trials each – Need to be approved my Ms. Klink before you can start

Create a Data Table Must be approved Must contain labels, a title, trials and conditions

Design Your Own Experiment You will need: 1.A purpose question 2.A hypothesis 3.A set of SPECIFIC, SCIENTIFIC procedures 4.A data table