HAPPY TUESDAY Copy this statement in your Bellwork: I will come into the room quietly. I will collect my papers from the front table. I will put away my cell phone and headphones before I walk into the room. I will sit down in my seat and begin doing the bellwork. I will do my best, participate in class, and learn biology.

A LL CELLS ARE SURROUNDED BY A THIN, FLEXIBLE BARRIER KNOWN AS A CELL MEMBRANE.

T HE TWO MAIN FUNCTIONS ARE : 1) TO REGULATE WHAT ENTERS AND LEAVES THE CELL 2) TO PROVIDE PROTECTION AND SUPPORT.

M EMBRANES FALL INTO THREE CATEGORIES … They can be permeable, meaning that the membrane is penetrable and will allow liquids, particles and gasses to pass through it. Which of the objects from the activity were completely permeable?

They can be impermeable, meaning that the membrane is not penetrable and will NOT allow liquids, particles or gasses to pass through it. Which of the objects from the activity were completely impermeable?

Finally, they can be Selectively permeable, meaning that some substances can pass across while others cannot. Biological membranes, like the ones around your cells, are selectively permeable. Which of the objects from the activity were selectively permeable?

W HAT IS THE CELL MEMBRANE COMPOSED ( MADE ) OF ? (3 TYPES OF MOLECULES )

The cell membrane is composed of a double-layered sheet called a lipid bilayer. DRAW THIS! Lipid Phosphate carbohydra te Bi- means 2 Also called the phospholipid bilayer

P ROTEINS ARE EMBEDDED IN THE LIPID BILAYER. Proteins form channels or pumps that help move large materials across the cell membrane.

Carbohydrates are attached to many proteins embedded on the outside of the bilayer. The carbohydrates allow individual cells to identify one another.

HW #3 R EGULAR B IOLOGY (P ERIODS 4 & 5) T ONIGHT ’ S H OMEWORK … Page 13 of your I.A.N. in Cornell Notes There are several ways to access the homework video: Search “ Molecule Alyssa Dolny ” on YouTube Go to my website and click on the “Lessons and Assignments” link

UPDATE I.A.N. T HERE WILL BE A CHECK ON F RIDAY ALONG WITH A B UFF B INDER C HECK

VOCABULARY Cell Prokaryote Eukaryote Endosymbiotic Theory Cell Membrane Function Permeable Impermeable Selectively Permeable (Semi-Permeable) Phospholipid Bilayer Hydro Phobic Phillic

Front Back Vocabulary Word Definition of the word. A sentence that uses the word. A real-world example of the word. A drawing that reminds you of the definition of the word. (Must use at least one color.)

Front Back Biology The study of life. Biology allows us to understand the living world around us. Ecology is a type of biology that studies the environment.

The concentration is the amount of a substance dissolved into water.

A concentration gradient is a difference between two concentrations. Diffusion is the movement of particles down the concentration gradient. High Concentration Low Concentration Crystal Light Commerical

When the concentration of a solute is the same throughout a system, the system has reached equilibrium. When equilibrium is reached, particles do continue to move across the membrane.

When particles move from an area of high concentration to an area of low concentration. This is known as diffusion.

Diffusion of WATER through a selectively permeable membrane is called osmosis. Remember: SALT SUCKS

I SOTONIC MEANS “ SAME STRENGTH ”. H YPERTONIC MEANS “ ABOVE STRENGTH ”. H YPOTONIC MEANS “ BELOW STRENGTH ”. Draw This Label: Isotonic Water: Same Solute: Same Label: Hypertonic Water: Low (outside cell) Solute: High Label: Hypotonic Water: High (outside cell) Solute: Low