BIO 198 Cincinnati State

Week # 9 Lecture pp 129-133Lecture Presentations for Integrated Biology and Skills for Success in ScienceBanks, Montoya, Johns, & Eveslage

Expectations for the courseCommunityWorking with othersin class, in lab, in study groupsLearningComplete all assignments for deep comprehensionRespectFellow students, instructors and self

When we all do better, we all do better. If you know the topic under discussion, practice your skills as a coach or teacherhelp others in class or in study groups that you set up. Be patient with yourselfthere is always a delay from the exposure of a new idea to the comprehension of the new idea. And then celebrate your learning and the learning of your fellow students. Attend all classes, and be on time. Come prepared with a positive attitude. Review your work and your notes, and review the text everyday. Complete all assignments to the best of your ability, and ask for help when you need it. When your grade is in the computer, its too late to ask for help.2Guiding Principles for the CourseLooking at seemingly simple things deeply

Conceptual understanding

Practical Applications

Contextualized Some of the material may appear to be simple. The trick is to gain a deep conceptual understanding of the process, then you can apply it to complex situations with ease. We will be taking seemingly simple processes and putting them into new situations. When someone does not have a strong foundation to stand on, problems can arise when facing challenges. This course will provide to you the tools you will need to understand many of the complex concepts found in the biological world.3

Transport Mechanisms, Organelles, By the end of the lecture today, students will be able to: Explain the importance of and describe the processes of diffusion, osmosis, facilitated diffusion and active transport. Describe which types of membrane transports require energy and which do not require energy.List the major organelles in a eukaryotic cell and describe their major roles in the cell.

4Membrane Transportplasma membrane a barrier and a gateway between the cytoplasm and ECFselectively permeable allows some things through, and prevents other things from entering and leaving the cell

passive transport mechanisms requires no ATP random molecular motion of particles provides the necessary energydiffusion, osmosis, facilitated diffusion

active transport mechanisms consumes ATPactive transport and vesicular transport

Simple DiffusionSimple Diffusion the net movement of particles from area of high concentration to area of low concentration due to their constant, spontaneous motion

Also known as movement down the concentration gradient concentration of a substance differs from one point to another

DowngradientUpgradientCy.

OsmosisOsmosis - flow of water from one side of a selectively permeable membrane to the otherfrom side with higher water concentration to the side with lower water concentrationreversible attraction of water to solute particles forms hydration spheresmakes those water molecules less available to diffuse back to the side from which they came

Aquaporins - channel proteins specialized for passage of water

Side ASide B(a) Start.3-10Facilitated Diffusionfacilitated diffusion passive transport of solute through a membrane down its concentration gradient

does not consume ATP

solute attaches to binding site on carrier, carrier changes confirmation, then releases solute on other side of membrane

.ECFICF123A solute particle entersthe channel of a membraneprotein (carrier).The solute binds to a receptorsite on the carrier and thecarrier changes conformation.The carrier releases thesolute on the other side ofthe membrane.Active Transportactive transport carrier-mediated transport of solute through a membrane up (against) its concentration gradientATP energy consumed to change carrier Examples of uses:sodium-potassium pump keeps K+ concentration higher inside the cellbring amino acids into cellpump Ca2+ out of cell

Sodium-Potassium Pumpeach pump cycle consumes one ATP and exchanges three Na+ for two K+

keeps the K+ concentration higher and the Na+ concentration lower with in the cell than in ECF

necessary because Na+ and K+constantly leak through membranehalf of daily calories utilized for Na+ - K+ pump

.2 K+ inExtracellularfluidIntracellular fluid+ATPPiADP +3 Na+ outhttp://www.youtube.com/watch?v=RPAZvs4hvGA The Cell Interiorstructures in the cytoplasmorganelles, cytoskeleton, and inclusionsall embedded in a clear gelatinous cytosolOrganelles internal structures of a cell that carry out specialized metabolic tasksmembranous organelles those surrounded by one or two layers of unit membranenucleus, mitochondria, lysosome, peroxisome, endoplasmic reticulum, and Golgi complexorganelles not surrounded by membranesribosome, centrosome, centriole, basal bodies

NucleusLargest organelle (5 m in diameter)most cells have one nucleusa few cells are anuclear or multinucleatenuclear envelope - two unit membranes surround nucleusperforated by nuclear pores formed by rings of proteinregulate molecular traffic through envelopehold two unit membranes togethernucleoplasm material in nucleuschromatin (thread-like matter) composed of DNA and proteinnucleoli one or more dark masses where ribosomes are produced

endoplasmic reticulum - system of interconnected channels called cisternae enclosed by unit membrane

rough endoplasmic reticulum composed of parallel, flattened sacs covered with ribosomescontinuous with outer membrane of nuclear envelopeproduces the phospholipids and proteins of the plasma membranesynthesizes proteins that are packaged in other organelles or secreted from cellEndoplasmic ReticulumEndoplasmic Reticulumsmooth endoplasmic reticulumlack ribosomescisternae more tubular and branchingcisternae are thought to be continuous with those of rough ERsynthesizes steroids and other lipidsdetoxifies alcohol and other drugsmanufactures all membranes of the cell

rough and smooth ER are functionally different parts of the same network

RibosomesRibosomes - small granules of protein and RNAfound in nucleoli, in cytosol, and on outer surfaces of rough ER, and nuclear envelope

they read coded genetic messages (messenger RNA) and assemble amino acids into proteins specified by the code

Golgi ComplexGolgi complex - a small system of cisternae that synthesize carbohydrates and put the finishing touches on protein and glycoprotein synthesis

receives newly synthesized proteins from rough ERsorts them, cuts and splices some of them, adds carbohydrate moieties to some, and packages the protein into membrane-bound Golgi vesicles

some become lysosomessome migrate to plasma membrane and fuse to itsome become secretory vesicles for later release

LysosomesLysosomes - package of enzymes bound by a single unit membraneextremely variable in shape

Functionsintracellular hydrolytic digestion of proteins, nucleic acids, complex carbohydrates, phospholipids, and other substances

autophagy digest and dispose of worn out mitochondria and other organelles

autolysis cell suicide some cells are meant to do a certain job and then destroy themselves

3-24Mitochondrionmitochondria organelles specialized for synthesizing ATP

variety of shapes spheroid, rod-shaped, kidney bean-shaped, or threadlike

surrounded by a double unit membraneinner membrane has folds called cristaespaces between cristae are called matrixmatrix contains ribosomes, enzymes used for ATP synthesis, small circular DNA molecule mitochondrial DNA (mtDNA)

Powerhouses of the cellenergy is extracted from organic molecules and transferred to ATP

MatrixCristaOuter membraneInner membraneIntermembranespaceMitochondrialribosome.3-25Mitochondrion

MatrixCristaOuter membraneInner membraneIntermembranespaceMitochondrialribosome1 mhttp://www.youtube.com/watch?v=aczbMlSMr8U Exit Quiz1). What transport mechanism is responsible for moving water molecules from an area of high concentration to low concentration?2). In order for active transport mechanism to work there must be an input of what molecule? Why this molecule?3). What part of the nucleus is responsible for producing rRNA (ribosomes)?4). What organelle is responsible for modifying proteins after they are synthesized?5). Why is the mitochondria known as the powerhouse of the cell?