Question of the Day OCT 21 The cell membrane contains which of the following sets of three organic compounds. A. Carbs, Lipids, Nucleic Acids B. Lipids, Proteins, Enzymes C. Carbs, Lipids, Proteins D. Carbs, Lipids, Fatty Acids

DO NOW OCT 21 Compare the processes of diffusion and facilitated diffusion.

ANSWER OCT 21 Diffusion and facilitated diffusion move molecules across the cell membrane from an area of high concentration to low concentration. Both processes do NOT require energy. Facilitated diffusion uses protein channels to allow larger molecules such as glucose to cross the cell membrane.

AGENDA OCT 21 BIG Question: What are the main functions of the cell membrane and the cell wall? 1. QoD and DO NOW 2. Homework Check 3. Section 7-3 Cell Boundaries 4. Cell membrane, Cell Wall, and Diffusion 5. Review and HOMEWORK STUDY your notes!!! QUIZ/TEST this week!

CELL STRUCTURE and FUNCTION CHAPTER 7 CELL STRUCTURE and FUNCTION

Cell Membrane separates the cell from its surroundings regulates what enters and leaves the cell aids in the protection and support of the cell composed of a double layer of lipids, known as a bilayer contain proteins that act as channels through which molecules pass or pumps to push molecules through carbohydrates are also attached to proteins or lipids and act like identification cards Template copyright www.brainybetty.com 2005 2/17/2019

Template copyright www.brainybetty.com 2005 2/17/2019

Cell Wall cell structure that surrounds the cell membrane for protection and support found in plants, algae, and some bacteria very porous and allows water, oxygen, carbon dioxide, and other substances through Made of a tough fibrous material called cellulose: makes the wall elastic so it can stretch and grow Template copyright www.brainybetty.com 2005 2/17/2019

7-3 CELL BOUNDARIES Movement of Materials Across the Cell Membrane diffusion: process by which molecules move from areas of higher concentration to areas of lower concentration equilibrium occurs when the concentrations on both sides of the membrane are the same permeability determines which substances move across the membrane Template copyright www.brainybetty.com 2005 2/17/2019

OSMOSIS diffusion of water molecules through a selectively permeable membrane pass through rapidly Water moves from an area of low solute concentration to high solute concentration.

OSMOSIS osmotic pressure: water pressure cells protect themselves with: cell walls bathing cells in blood contractile vacuoles to pump out water

Effects of Osmosis on a Cell Concentration of Solutes ISOTONIC: concentration of solutes is same inside/outside cell Cell does NOT gain or lose water. HYPERTONIC: solution has higher solute concentration than the cell Cells shrink as water moves from an area of lower concentration (the cell) to a higher concentration (outside the cell). HYPOTONIC: solution has lower solute concentration than the cell. Cells will burst as water moves into the cell.

OSMOSIS VIDEO CLIP http://www.youtube.com/watch?v=7-QJ- UUX0iY 0:59 Hypotonic – Water molecules enter the cell 3:10 Hypertonic – Water molecules exit the cell 4:20 Isotonic – Net movement of water molecules is equal

Facilitated Diffusion some molecules are too large to pass through cell membrane molecules too large must pass through a protein channel embedded in the cell membrane still driven by diffusion Template copyright www.brainybetty.com 2005 2/17/2019

Active Transport requires energy allows material to move against a concentration difference two types: carried through membrane-associated pumps (proteins) large amounts of material are transported through movements of the cell membrane Template copyright www.brainybetty.com 2005 2/17/2019

Active Transport endocytosis – the engulfing of large molecules to be taken into the cell. TWO EXAMPLES of Endocytosis phagocytosis: extensions of cytoplasm surround and engulf large food particles. Means “Cell eating” pinocytosis: tiny pockets form along the membrane fill with liquid and pinch off to form vacuoles within the cell. exocytosis: the removal of large molecules from the cell

EXIT PASS REVIEW 1. Describe the composition of the cell membrane? 2. Why is the cell membrane important to a cell? 3. What is diffusion?

DO NOW What are the four levels of cell specialization found within an organism?

7-4 Diversity of Cellular Life Cell Specialization: cells within an organism develop in different ways to perform different tasks. Red Blood Cells contain hemoglobin. Protein that binds oxygen in the lungs and transports it throughout the body. Pancreatic cells produce enzymes to assist in the digestion of foods. Packed with ribosomes and Rough ER. Proteins are made and packaged for this specialized job. Template copyright www.brainybetty.com 2005 2/17/2019

7-4: Levels of Organization cells: basic unit of life tissues: group of similar cells that perform similar functions organs: a group of similar tissues that perform similar functions organ systems: group of similar organs that perform similar functions muscular, skeletal, digestive, circulatory, etc. Template copyright www.brainybetty.com 2005 2/17/2019