SSR First 10 minutes of class Agenda 92512

SSR First 10 minutes of class

Agenda 9/25/12 ---Day 4 � Cell Race � Review graphic organizer � Notes � Cell Test-Tuesday 10/2

The Cell � Smallest unit of all living things � Composed of organelles � Each organelle performs specific jobs so the cell can do it’s job

Organelles Know location of and function of the following sructures � Cell membrane � Nucleus � nucleolus � Chromatin � Nuclear envelope � Microvilli � Cytoplasm � Mitochondria � Golgi body � Endoplasmic Reticulum � Ribosome � Centrioles

Collins I � Describe three organelles discussed yesterday � Three lines

Agenda 9/26 ---Day 5 � Discuss cell � Continue notes � Cell diagram and plasma membrane diagram color and label

Plasma Membrane � The barrier surrounding each cell � Separates the cells contents from the surrounding environment � Is selectively permeable � This is the cells way of maintaining boundaries

Structure of plasma membrane � Phospholipid bi-layer � Meaning two layers � Each layer consists of a lipid tail connected to a phospo- head � The tails face each other, away from the external or internal environments

Phospholipid bi-layer �Hydrophobic ◦ The lipid tails are water insoluble ◦ They are “water fearing” ◦ They are non-polar �Hydrophilic ◦ The protein heads of each Phospholipid is water soluble ◦ They are “water loving” ◦ They are polar and interact well with other polar substances

Throughout the membrane you will find � 1. Proteins � 2. cholesterol ◦ a. Peripheral proteins act as binding sites or receptors ◦ b. Integral proteins- proteins that span the membrane act as transport protein ◦ c. Glycoprotein- act as markers, which allow your cells to be recognized as “self” cells ◦ Help to stabilize the plasma membrane

Types of transport proteins � Channel Proteins ◦ Passive movement of material through pores � Carrier proteins ◦ Molecule will bind to the carrier protein causing it to open, allowing passage into the cell

Channel proteins � Use passive transport ◦ Do NOT require energy ◦ 1. diffusion- molecules move across membrane through pores along a concentration gradient (high to low) ◦ 2. filtration-movement of water and other solutes from high to low concentration �Based on a difference in water pressure between external and internal environment �Pushes out solutes �Occurs in the kidneys

Carrier proteins � Facilitated diffusion- ◦ concentration gradient still needed ◦ Protein carrier is used because molecules are too large to enter pores ◦ Still passive transport, just needs help ◦ No energy because it is using a gradient � Solute Pump (example Na/K exchange pump) ◦ Moves molecules or ions too large to enter on own AGAINST a concentration gradient ◦ REQUIRES ENERGY (active transport)

Cells join to form tissue � Several junctions are present in order for the cells to continue doing their jobs, while communicating with adjacent cells all the while staying anchored to each other!

Define the following terms and provide an example of where it occurs page 59 � Membrane ◦ ◦ junctions: Tight junctions Desmosomes Gap junctions Microvilli