1. Structure Leads to Function;The Cell Membrane

2. The Words… STRUCTURE: the shape, organization, and/or chemical makeup of an object FUNCTION: what something does, its role STRUCTURE always leads to FUNCTION!

3. Familiar Examples… Eating Utensils: Fork, Spoon, & Knife These have distinct shapes that determine their use

4. A few microscopic examples… Microtubules

5. A few microscopic examples… Proteins… in all their variety

6. Take Home Message? STRUCTURE LEADS TO FUNCTION!!!!!

7. The Plasma (cell) Membrane Structure: Made up of a lipidbilayer, proteins, & cholesterol

8. Plasma Membrane Functions: Forms the principle barrier between the inside of the cell and its environment Protect the cell Regulate traffic into and out of the cell Support the creation of multiple concentration gradients and an electrostatic gradient between the inside and outside of the cell Maintain the overall integrity of the cell, particularly in cold temperatures

9. Structure of a Phospholipid

10. Chemical Structure The chemical makeup of a phospholipid causes multiple phospholipids to naturally align themselves in a characteristic bilayer shape (structure). This is due to the chemical properties of the phospholipid: the polar,hydrophilic head and the hydrophobic tail Function: hydrophilic region allows the plasma membrane to associate with water, other polar molecules, & hydrophilic proteins on the inside and outside of the cell Function: hydrophobic region creates a hydrophobic barrier to keep out large and/or polar/hydrophilic molecules

11. The Polar Head Structure: The “head” has a positively charged nitrogen atom and a negatively charged oxygen Function: The polarity of the head allows the membrane to associate easily with other polar molecules, such as H2O

12. Cholesterol Functions Function 1: Easily inserts into the plasma membrane between the tails of different phospholipids, thus filling in the gaps between phospholipids and helping to keep out other small molecules Function 2: Pay attention… it stiffens the membrane at “normal” temperatures, but keeps the membrane fluid at cold temperatures

13. Membrane Proteins Have both hydrophilic and hydrophobic regions, allowing them to associate with the plasma membrane in a variety of ways Come in all different shapes and thus, perform many different functions Specifically, help regulate traffic across the plasma membrane

14. Types of Transport There are 2 main categories of transport: Passive Active

15. PASSIVE TRANSPORT Does NOT require Energy Gradient = “change in the value of a quantity (as temperature, pressure,or concentration) with change in a given variable and especially per unit on a linear scale”

16. Facilitated Diffusion A form of Passive Transport… Facilitated: to help or allow Channel proteins, Along their concentration gradient

17. Active Transport Necessary when transporting a particle against (up) its concentration gradient REQUIRES ENERGY ATP

19. 5 levels of organization 1.) Protoplasmic organization Unicellular organisms: protozoa 2.) Cellular Organization Sponges Cells that are functionally differentiated and exhibit a division of labor 3.) Tissue Level Cells organized into layers which form tissue

20. 4.) Organs Composed of one or more tissues. Have more specialized funtion than tissue Flatworms: reproductive organs, eyespots, feeding structures 5.) System level Organs work together to form systems: circulatory, digestive, reproductive, respiratory

21. Types of tissue Tissue: a group of similar cells specialized for the performance of a common function

22. Epithelial tissue Epithelial Absorb: lining of small intestine Transport: kidney tubules Excrete: sweat glands Protect: skin Contain nerve cells for sensory info Tastebuds The structure relates to their function.

23. Connective tissue Connective Support and bind Distributed throughout an extracellular matrix Loose connective tissue Elastic Binds skin to muscle Fibrous connective tissue Tendons (muscle to bone or other muscle) Ligaments (bones to bones) Adipose tissue: Store lipids Form fat

24. Muscle tissue Muscle Tissue Allows movement Skeletal Smooth Cardiac

25. Nervous Tissue Nervous Tissue Impulse-conducting cells Neurons

26. Organs Functional units of the body that are made up of more than one tissue Heart Lungs Liver Spleen kidney

27. Organ Systems Group of organs that complete a function Work together Integumentary Skeletal Muscular Nervous Endocrine Circulatory Respiratory Digestive Reproductive