Cellular Energetics

Cellular Energetics

Catabolic pathways

Fermentation: Partial degradation (O2) Cellular respiration: Full degradation (O2) Organic compounds + O2 CO2 + H2O +

energy (gasoline burning) C6H12O6 + 6O2 6CO2 + 6H2O + energy

Enzyme facilitate the break down of organic fuels to CO2 in a SERIES of steps. Why not just one step?

Electrons (along with a proton) are stripped from glucose, but not directly to O2, instead they are transferred to…

NAD Conezyme derived from the vitamin niacin NADox vs NADre

Very little PE lost Energy can be tapped into when ATP needs to be made

How do electrons finally reach oxygen?

Substrate level phosphorylation

Enzymes transfer a phosphate group from the substrate to ADP

In oxidative phosphorylation inorganic phosphate is added to ADP

Glycolysis “splitting of sugar”

Location? cytosol Inputs? Glucose, ATP Outputs? ATP, NADH, H+ , Pyruvate Purpose? Energy

Fermentation

Sources of energy

Autotrophs (self-feed from CO2 and inorganic materials): plants, some algae, some bacteria Synonym: Producers

Photosynthesis (photoautotroph)

Chemosynthesis (chemoautotroph)

Chloroplast structure

Read through :birth of complex cells to get further detail about other plastids and organelles such as peroxisomes

Water: rootsveinsmesophyll cellsSugar: mesophyll cellsveinsrest of plantCO2, O2 stomata

Absorbing/reflecting light Problem: How do plants utilize

energy from light to produce carbohydrates?

Properties of light While traveling, acts as a

wave (properties depend on this wavelength)

When interacting with matter (like your clothes) acts as a particle

Photon: Discrete packet of light

Pigment structure/function

Pigment structure/function

When chlorophyll absorbs light, energy is transferred to electrons.

Plant pigments

Chlorophyll a: primary pigmentChlorophyll b: broadens range of wavelengths that can be usedCarotenoids: Also broadens range, absorbs, dissipates excessive energy, prevents interaction w/ O2EAT YOUR CARROTS, why?

Light dependent reactions

Role of chlorophyll: Capture energy from light

Role of an electron carrier: transport electrons which carry the energy initially from light (NADP+ + 2e- + H+ NADPH)

Photosynthesis overview NADP+ : Same function as NAD+ Photophosphorylation

How do photosystems work?

Only photons with energy equal to the atoms ground state excited stated is absorbed Redox Why does isolated chlorophyll

fluoresce?

Noncylic electron flow

Noncylic electron flow

Noncylic electron flow

Noncylic electron flow

Noncylic electron flow

Noncylic electron flow

Cyclin electron flow

Function: Regenerate ATP lost through Calvin Cycle (more ATP consumed than NADPH)

Electron transport chain

Location: _____Input: ______Output: ___Purpose: _____

Chemiosmosis comparison

Calvin Cycle

Purpose: _____ Location: ____ Input : ____ Output : ____