AP Biology Discussion Notes Monday 10/6/2014

Questions?? ASK!!! If you have questions about any of the content, notes, discussion or images be sure to ASK!! Reach Ms. Jacobs by

Goals for the Day 1.Become familiar with the cell organelles and their functions. 2.Be able to describe the function of specific organelles, and which types of organisms have them 3.Describe how things are transported in/out of the cell

Question of the Day What cell part produces lipids and why is that so important?

Question of the Day What cell part produces lipids and why is that so important? Lipids make up EVERY membrane from our cell membrane to all of the membranes that surround Eukaryotic cell organelles (Ex. Mitochondria)

Functions of Smooth ER The smooth ER –Synthesizes lipids –Metabolizes carbohydrates –Detoxifies drugs and poisons –Stores calcium ions

Let’s think more about cells…. What is the typical size of a cell (generally)? Why do you think this is? Are there exceptions (cells that are a different size)?

Why cells are SO small Metabolic requirements set upper limits on the size of cells The surface area to volume ratio of a cell is critical As the surface area increases by a factor of n 2, the volume increases by a factor of n 3 Small cells have a greater surface area relative to volume

Why cells are SO small So……..basically cells need to be small so that they can move things in and out efficiently. If we were one giant cell we couldn’t use diffusion to get the nutrients we need into and the wastes we don’t out of the cell.

Surface area increases while total volume remains constant Total surface area [sum of the surface areas (height  width) of all box sides  number of boxes] Total volume [height  width  length  number of boxes] Surface-to-volume (S-to-V) ratio [surface area  volume] Figure 6.7

Why aren’t cells infinitely small?

We still need some cell parts inside of there! If this is really what limits how small a cell can be, which would you expect to be smaller: Prokaryotic or Eukaryotic cells?

How big is a (typical) cell? See if you’re right! Cell Size

Passive vs. Active Transport

Concentration Gradient

Passive Transport WITH the Gradient NO ATP NEEDED!!! Diffusion Osmosis --hypo, hyper, isotonic --turgor pressure --cytolysis --plasmolysis Facilitated Diffusion (channel/carrier proteins)

The “tonics”

Does size affect what can move across the membrane?

Questions? What questions do you have from the cell notes video?

How things work together (Nucleus, SER, RER, Ribosomes, Golgi, Cell Membrane)

Fluid-Mosaic Model of the Plasma Membrane Surround cytoplasm; regulates what enters/leaves; semi-permeable; phospholipid bilayer

Exocytosis

Endocytosis Mechanisms

How things work together (Nucleus, SER, RER, Ribosomes, Golgi, Cell Membrane)

Figure 6.11a Smooth ER Rough ER Cisternae Ribosomes Transport vesicle Transitional ER Nuclear envelope ER lumen

Figure 6.11b Smooth ER Rough ER 200 nm

Functions of Smooth ER The smooth ER –Synthesizes lipids –Metabolizes carbohydrates –Detoxifies drugs and poisons –Stores calcium ions

Functions of Rough ER The rough ER –Has bound ribosomes, which secrete glycoproteins (proteins covalently bonded to carbohydrates) –Distributes transport vesicles, proteins surrounded by membranes –Is a membrane factory for the cell

The Golgi apparatus consists of flattened membranous sacs called cisternae Functions of the Golgi apparatus –Modifies products of the ER –Manufactures certain macromolecules –Sorts and packages materials into transport vesicles The Golgi Apparatus: Shipping and Receiving Center

Figure 6.12 cis face (“receiving” side of Golgi apparatus) trans face (“shipping” side of Golgi apparatus) 0.1  m TEM of Golgi apparatus Cisternae

Lysosome Lysosomes- small, spherical organelles that contain the cell’s digestive enzymes Function: Digestion & Recycling (The garbage man of the cell)

Cell Reading

Nobel Prize in Physiology or Medicine 2014

Species of the day 10/6 Curculio spp. Acorn Weevil

Species of the day 10/6 Curculio spp. Acorn Weevil Do the acorn and the weevil share the same cell parts? EXPLAIN your answer!