Get ready for lab quiz 14 days until AP BIO Final -75 questions -Photo/cellular respiration -Cell communication + cell cycle (Chapters 11-13) -Ecology -Cell -Evolution -Labs -Water and Chemistry of Life -Colored book CAN be used on FINAL

Monday, May 14 th at 8am AP Biology Exam

Lab Quiz—Photo + Cellular Resp 1.In the cell respiration lab, the role of KOH was___________________ 2.In the cell respiration lab, we measured_________________________ 3.Oxygen is needed by living organisms to____________________ 4.In the chromatography lab, the pigments were found in the spinach leaf were________ 5.The reason that pigments had different Rf values is________________

Lab Quiz—Photo + Cellular Resp 1.In the cell respiration lab, the role of KOH was to make CO2 a solid; reduce the volume 2.In the cell respiration lab, we measured the O2 consumed 3.Oxygen is needed by living organisms to collect the electrons in the ETC 4.In the chromatography lab, the pigments were found in the spinach leaf were chlorophyll a, chlorophyll b, xanthophyll, and carotene 5.The reason that pigments had different Rf values is that they have different properties and react differently with the chromatopraphy paper AND have high/low soluability in the solvent

Averages for Lab Report—2 LABS DUE FRI Averages from Chromatography Lab Chlorophyll a=0.249 Chlorophyll b=0.370 Xanthophyll=0.446 Carotene=1

OIL RIG OIL=Oxidized Involves Losing electrons RIG=Reducing Involves Gaining electrons

Oxidized or Reduced? NAD +  NADH O2  H2O (cellular respiration) H2O in photosynthesis

Dispatch 1)How do you think one part of the body communicates with the other over SHORT distances? Over LONG distances? 2)What do you think the jar is representing? Open jar=2 Phosphates (ADP); Closed jar=3 Phosphates (ATP)

Cell Communication ideo;_ylt=A0oGdWOXyBFPwhsAQ5VX NyoA?p=dominoes%20knocking%20o ver&fr=yfp-t-701&fr2=piv-web

The Cellular “Internet” Within multicellular organisms, cells must communicate with one another to coordinate their activities A signal transduction pathway is a series of steps by which a signal on a cell’s surface is converted into a specific cellular response Signal transduction pathways are very similar in all organisms, even organisms as different as unicellular yeasts and multicellular mammals

Local (Short-Distance) Signaling Cells may communicate by direct contact  Plasmodesmata in plant cells  Gap junctions in animal cells Animal cells can also use cell-cell recognition  Membrane-bound surface molecules can interact and communicate

Local (Short-Distance) Signaling Messenger molecules can also be secreted by the signaling cell Paracrine signaling:  One cell secretes (releases) molecules that act on nearby “target” cells  Example: growth factors Synaptic Signaling:  Nerve cells release chemical messengers (neurotransmitters) that stimulate the target cell

How do you think one part of the body communicates with the other over LONG distances?

Long-Distance Signaling Endocrine (hormone) signaling  Specialized cells release hormone molecules, which travel (usually by diffusion through cells or through the circulatory system) to target cells elsewhere in the organism

The body needs more of protein X. DNA  RNA  Protein X How do we turn on transcription?

Phosphorylation The protein being phosphorylated GAINS a phosphate A molecule that is phosphorylated has an increased chemical reactivity; it is primed to do cellular work.

The Three Stages of Cell Signaling There are 3 stages at the “receiving end” of a cellular conversation: 1.Reception 2.Transduction 3.Response

Stage 1: Reception The target cell “detects” that there is a signal molecule coming from outside the cell  The signal is detected when it binds to a protein on the cell’s surface or inside the cell  The signal molecule “searches out” specific receptor proteins The signal molecule is a ligand It is a molecule that specifically binds to another one (think enzymes!)

Stage 2: Transduction This stage converts the signal into a form that can bring about a specific cellular response  One signal-activated receptor activates another protein, which activates another molecule, etc., etc.  These act as relay molecules  Often the message is transferred using protein kinases, which transfer phosphate groups from ATP molecules to proteins

Stage 2: Transduction

Stage 3: Response The signal that was passed through the signal transduction pathway triggers a specific cellular response  Examples: enzyme action, cytoskeleton rearrangement, activation of genes, etc., etc.  Diagram example: transcription of mRNA

The Specificity of Cell Signaling The particular proteins that a cell possesses determine which signal molecules it will respond to and how it will respond to them Liver cells and heart cells, for example, do not respond in the same way to epinephrine because they have different collections of proteins

Animation nt/chp15/15020.html nt/chp15/15020.html 1) What is flight or fight? 2) What is glycogen?

Word bank: signaling molecule, cell receptor, signal transduction pathway, nuclear signaling, cascade, phosphorylation, ATP, protein, response, nucleus, mRNA, second messenger