September 7, 2007Warm-Up question

What does making cheese have to do with

biotechnology?

Agenda

• Warm up/ take attendance• Collect parent signatures• Go over cheese day 2 instructions• Fermentation lab!- go over

directions• Do the Cheese Day 2 and

Microbial Brew labs• Work on your poster assignment

during “down time”!

Homework

• Finish poster so you can present on Monday

• Continue interacting with the message board

Cheese lab

• Get a piece of cheese cloth that is big enough to set atop of a beaker

• Get another 1 L beaker (hopefully there are enough)

• Get your cheese out of the incubator

• Put the cheesecloth on top of the empty beaker, make a little pouch to start collecting the cheese

More Cheese directions

• Carefully pour the cheese into the cheesecloth

• What is the stuff going in the cheesecloth called?

• What is the stuff that goes through the cheesecloth called?

• Did you take notes and write down this information when we went over it?

More cheese directions

• Tie up the edges of the cheesecloth. • Label your cheesecloth with your group

number on a piece of tape• Tie your cheese pouch to a ring that is

on the ringstand. • Please make sure there is a plastic

bucket underneath your cheese wad• The cheese will sit in the refrigerator

until Monday, continuing to drain

Questions?

MicroBrew

• Make sure Ms Getz passes out the directions if they are not at your desk yet

• We are actually doing two bottles per PERSON (not per group)

• The reason we are doing two bottles is because you are going to do an experiment on top of a cookbook recipe

• Bottle two will have ONE variable changed

Microbrew instructions

• 1. Obtain a 500 mL plastic bottle and label it with your name and group number.

• 2. Weigh 75 g of sugar into your weigh boat.

• Oops- we don’t have clean weigh boats, but we do have clean 400 mL beakers; Please use a 400 mL beaker to weigh the 75 g.

• 3. Pour 175 mL of water from the plastic bottle into a beaker. (It does NOT have to be exactly 175 mL.)

• If you are using the 100 mL beaker, it is ok if you pour out 175 mL but only keep 100 mL to use later

• Worst case scenario, we open a new bottle of water to have as a water supply at the end (see instruction #7)

• 4. Carefully pour 75 g of sugar into the bottle of water. Cap the bottle. Shake to dissolve the sugar.

• Don’t rush because we do not want you to spill sugar everywhere

• 5. Using a graduated pipette and the plastic pipettor, measure 3 mL of flavoring extract and put it in the 500 mL bottle. Swirl lightly to mix. Write down the flavor you used.

• Graduated pipettes: two things you need to know– 1. Do NOT hold it in the middle when you

put it in the plastic holder (you do not want the glass to go through your hand)

– 2. Their scale is backwards. To measure 3 mL you are actually bringing volume up to the “2” mark.

• 6. Using a graduated cylinder, measure 30 ml of yeast solution and transfer the solution into the plastic bottle.– We have two clean graduated cylinders

for you to use.

• 7. Partially refill the bottle with the water you previously poured into the beaker. Add water until there is a 5 cm space left at the top of the bottle.

• 8. Be sure to twist the cap on your bottle securely.

• 9. Clean up your lab station.

–Remember: we have mice and cockroaches- please do NOT leave any food or sugar around for them to enjoy

• 10. Put your bottle in one of the plastic storage boxes. We are going to let it ferment for a few days.

Questions?Preguntas?

Variables

• What is a variable?

• What are some examples of variables in this lab?

• How could they be changed?