Do Now

1. Do Now • Connect the dots using four straight lines without removing your pen from the paper. • Bonus challenge: can you do it using only 3 straight lines?

2. solutions

3. Unit two: building blocks of life Active and Passive Transport

4. Goals • 80% mastery of content • 80% mastery of lab material • 3 point increase on ACT

5. Bouncers at a concert… • You are a bouncer at a concert • You are a little bit shady. • Some people can pay you to let them in, even if they don’t have tickets.

6. Question 1: How much money would Beyonce and David Beckham have to pay you to let them into the concert?

7. Question 2 How much money would these people have to pay you to let them into the concert?

8. Bouncers at a concert… • Cell membranes work the SAME way as bouncers • Some cells can get in, some can’t • This setup is called a SEMIPERMEABLE membrane

9. Diffusion: In concerts • This is sneaking in the back door of the concert. There are NO bouncers here! • No cell membrane blocking movement of particles • Requires NO energy from the bouncers (cell)

10. Diffusion: In cells… • EASY to do • Movement of particles from an area of HIGH concentration to an area of LOW concentration • Requires no energy for the bouncers – it just happens. • This is called PASSIVE TRANSPORT

11. Examples of Diffusion • Perfume • Air in a tire • Oxygen across a cell membrane • Food coloring into water • Smells spreading from the oven to the rest of the house

12. Passive transport: Osmosis • DIFFUSION of a substance through a SEMIPERMEABLE membrane • that’s the bouncer at the concert • No extra energy is needed (like David Beckham) • This is called PASSIVE TRANSPORT • Examples • Plant roots absorbing water • Dipping a sponge in water • When you soak your hands for a long time and they start to look funny

13. Active transport • Some things take a extra ENERGY (or money) to get past the cell membrane (bouncers) • Moves against diffusion • This is a process called ACTIVE TRANSPORT • Examples • Moving in something we need (sugar) • Push out waste (CO2)

14. In pictures…

15. Stop and jot (2 minutes) • Questions to write about… • How do large particles, those too large to diffuse, get into cells? • Do cells have mouths? • Does swallowed food mix with directly with the other parts of a cell?

16. lab time • You will be working with the people at your group • Send one representative from your group to pick up… • One plastic bag • 4 pieces of starburst • DO NOT EAT THE STARBURST (yet!)

17. LAB TIME • Your plastic bag is your cell membrane • Your goal: to find a way to get the food INTO THE CELL • Rules • The candy must enter through a solid part of the bag. • The inside of the bag may not be directly open to the external environment. • The candies entering the bag must remain clustered together. • You may work with your hands in the bag in order to act as the inside of a cell. • The candy may be eaten only if it enters the bag "cell" under the specified conditions. • To qualify to EAT the starburst, your team must.. • 1) solve the problem • 2) draw a picture of how it happens

18. Solution? • What does this mean about how food enters a cell? • Is this passive or active transportation?