Wednesday, February 17, 2016 What are we doing today? Entry Task review lactase and lactose plan and prep Lactase Lab Welcome back! Add Protein Reading to assignment sheet (#3, due 2/18) Watch this video on Lactose Digestion in Infants: Does your body make the enzyme lactase? How do you know?

Protein Reading Regular Honors At the bottom of page one: cross out “nonfunctional” and write “non-working” In question #4: cross out “non-functioning” and write “non-working” Last paragraph of page one: cross out “functional” and write “working” Last sentence of page one: cross out “nonfunctional” and write “non-working” In question #5: cross out “non-functioning” and write “non-working”

Enzymes: A Fun Introduction Video start at 2:23

Main Ideas from Video 1) each enzyme has an active site 2) enzymes are very specific 3) enzymes are recycled

Lactase Enzyme Lactase is an enzyme produced by many organisms. It is found in the small intestine of humans and other mammals. Lactase is essential to the complete digestion of whole milk; it breaks down lactose, a sugar which gives milk its sweetness.

Drawing Carbohydrates monosaccharide glucose (1 single sub-unit) disaccharide lactose (glucose & galactose - 2 sub-units) Glucose Galactose

Lactase Enzyme breaks disaccharide (lactose) into two monosaccharides (glucose and galactose) Don’t forget water! Wow! Look at that shape!

lactose + water glucose + galactose Lactase Enzyme breaks disaccharide (lactose) into two monosaccharides (glucose and galactose) lactase lactose + water glucose + galactose

Don’t forget water!

Enzymes work because the active site matches the substrate.

Lactase works inside your small intestine. Human body temperature is 37 °C or 98.6°F Human small intestine acidity is pH 6.7

Lactase animation Lactase enzyme galactose glucose Have students narrate where this happens, and what is happening. Honors: hydrolysis! galactose glucose Lactase enzyme

Lactase Enzyme Lab Purpose: to determine how environmental factors affect the ability of an enzyme to do it’s job We will use glucose test strips that only test for ______________.

You could test temperature or pH. Let’s look at temperature first! lactase exposed to boiling temperature lactase exposed to room temperature Lactase exposed to freezing temperature Will these lactase solutions function? (break down lactose into glucose and galactose?)

You could test temperature or pH. Let’s look at pH now! lactase in acidic solution (pH 2) lactase in neutral solution (pH 7) lactase in basic solution (pH 9) Will these lactase solutions function? (break down lactose into glucose and galactose?)

The pH Scale

Lactase Lab Planning Template Before you leave today, you will finish: When you are done: update assignment sheet the first page get missing work (if you were absent or late) Variables Research Question do Protein Reading Hypothesis Looking for a special project? See Ms. Anne Materials and Procedure Be sure to: work with all your lab group members get signed off in three places

Temperature Three enzyme solutions (one lactase tablet + 200 mL of water): frozen then thawed room temperature boiled then cooled

pH Three enzyme solutions: acidic – pH 1 neutral – pH 7 basic – pH 14

Thursday, February 18, 2016 What are we doing today? Entry Task collect data for Lactase Lab graph lab group data Get a stamp for Protein Reading. Find a friend who is testing another manipulated variable and tell them your research question and hypothesis. Be prepared to share out your friend’s research question and hypothesis in three minutes.

Lactase Lab Scoring Rubric What is it? When would you like it? Class choice! a guide for writing your Lactase Lab Conclusion next Tuesday (similar to Gummy Bear Lab Conclusion, will count as a summative assessment) a checklist for what Ms. Wang and Ms. Anne will be grading you on today at the end of class tomorrow Monday Tuesday (day of conclusion writing)

Measuring Glucose Concentration put five drops of lactase solution into (nine) wells add five drops of milk wait five minutes dip test strip in milk and stir for 30 seconds (12 wells) remove the strip and wait three minutes compare your glucose stick to the chart below

When you are done collecting data… calculate your lab group’s averages start graphing your data x-axis label and units y-axis label and units appropriate scale graph title three data points be prepared to present your neat and accurate graph tomorrow

Friday, February 19, 2016 Talk with your lab group: What are we doing today? Entry Task present lab group data Toothpickase Enzyme Activity Talk with your lab group: What does your Lactase Lab data mean? Why do you think you got the results you did? Be prepared to share out in three minutes.

Data Presentations Why are we presenting data? Be sure to: Scientists share their data with other scientists and with citizens inform others build off each other’s research Talking through your ideas and explaining to others will help you learn We, our Biology class, are a learning community! all lab group members should speak speak loudly and clearly so others can hear explain your group’s graph manipulated variable responding variable data values reasoning

Toothpickase Enzyme Activity Read the Instruction sheet (class copy, return to Ms. Anne) Activity 1: designate two toothpickases, one recorder, one timer Activity 2: switch roles Throw away toothpicks Turn into inbox when done (Ms. Anne will give you a participation grade) Done? turn in/finish late work start a rough draft conclusion (CER) for Lactase Lab looking for a special project? See Ms. Anne 4th period: help Ms. Anne dump ice water, put away tubs + toothpicks + bowls