research presentations introduction –“sell” your research methods –very brief/relatively...
TRANSCRIPT
Research Presentations
• Introduction– “sell” your research
• Methods– Very brief/relatively extensive: depends on your topic– Judicious use of detail here: what do we need/want to know
• Results– How can they best be presented?
• Table of data or some sort of bar graph?• Should your y-axis be abs/time? Rate (mol/min)? %?• Are your units clear?
• Discussion/conclusion– What do your data mean?– Propose/suggest future directions that build off of your results
Research Presentations
• Graded (by me, with audience input) on:– Information, depth– How well the info comes across– Presentation style– All members get same grade
• Audience participation component– 10 points “Laboratory Participation”
• Suggestions:– Use pictures as much as possible
• Text to support your pictures
– Effective use of slide titles
Research Presentations
• Suggestions:– Use pictures as much as possible
• Text to support your pictures
– Effective use of slide titles– Effective presentation of your data– ORGANIZATION– Practice– Excitement/interest/(reasonable) creativity
Research Presentations
Chapter 13 (etc): Bioenergetics
• Metabolism:– Chemical reactions within a cell/organism– Often requires energy OR generates (harvests)
energy– “Catabolism”
• Degradative phase: breakdown of complex molecules into simpler products
– Typically accompanied by energy release
– “Anabolism”• Synthetic phase: creation of complex molecules from simpler
precursors– Typically requires energy input
Cells require a source of free energy to fight the second law of
thermodynamics• Total entropy increases
– Entropy is bad for cells– Free energy required to put things in order
(macromolecules, genetic info, etc)• Photosynthetic organisms
– Energy from solar radiation• Heterotrophic
– Energy from nutrient molecules (reduced hydrocarbons, for example)
• Solar/chemical energy transformed into chemical energy (esp. ATP) for bioavailability (biological work: coupling G>0 to G<0)
G vs. Keq
• Standard free energy change for a reaction (G’°) is constant
• Actual free energy change depends on standard G and temp/pressure, but more importantly reactant/product concentrations
]][[
]][[lnG' G
BA
DCRT
DCBA
• Spontaneity: determined by G, NOT G’°
• TheG for a typical reaction will decrease as it proceeds:
G = 0 when the reaction reaches equilibrium
• “Non-spontaneous” (G’°>0) reactions can be made spontaneous by:
1. “Mass action”: (sometimes unreasonable) increase in substrate concentrations
2. Coupling to spontaneous reactions (G’° is additive)
• Remember: we’re talking energetically spontaneous: there may still be a kinetic barrier
G vs. Keq
Chemical energy: making reactions spontaneous
• ATP hydrolysis: G’° ~ -30.5 kJ/mol
• Destabilized reactant (ATP)
• Stabilized products (PO4
3-+ADP+H+)
• Also important: kinetic stabilization of an inherently unstable compound: good storage molecule
Use of high energy phosphate compounds
• Not simply direct hydrolysis: phosphoryl transfer to intermediate or to protein
• Two step process:– Phosphoryl transfer:
‘activated’ compound– Phosphate
displacement:lower energy product