chemical pathways. food is your source of energy! calorie-amount of energy needed to raise the...
TRANSCRIPT
Chemical Pathways
Food is your source of energy!Calorie-amount of energy needed to raise the
temperature of 1 gram of water 1 degree Celsius1 kilocalorie is 1000 caloriesKilocalories are actually on the food package but we
call it CALORIESCells use calories from food to make ATP
Cellular energyBreak off the phosphate molecules and we release energyForm ADP
ADP is made back into ATP through cell respirationPlants and animals carrying out cell respiration.
Let’s watch a movie first.
http://www.brainpop.com/science/cellularlifeandgenetics/cellularrespiration/
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Cell Respiration Overview Release energy by breaking down glucose
and other food molecules with the help of oxygen
EquationOxygen + glucose= carbon dioxide + water+
ATPTake place in the mitochondriaTwo types of respiration:
Anaerobic-does not use oxygenAerobic-uses oxygen
GlycolysisTakes place in the
cytoplasm of the cellINPUTS: Glucose and
2 molecules of ATPOUTPUTS: 4 ATP (net
gain of 2) and pyruvic acid
NADH holds electrons for later use to create tons of energyCalled an electron
carrier
FermentationIf oxygen is not present, fermentation takes
place after glycolysisFermentation-releases ATP from food
without the use of oxygenTwo main types
Alcoholic fermentation-yeast form ethyl alcohol and carbon dioxide as waste; cause bread dough to rise
Lactic acid fermentation-lactic acid is producedCreated when your muscles do not have enough
oxygen to produce ATP when exercisingo Buildup of lactic acid creates a painful burning
sensationUnicellular organisms use to make food like
yogurt, cheese, sour cream, pickles, sauerkraut
Section 9.2 Kreb Cycle (citric acid cycle)
Pathway is aerobic-needs oxygen to function
Pyruvic acid from glycolysis enters the mitochondria
Carbon is removed from this acid to form carbon dioxide
Pyruvic acid will turn into acetyl CoA
Acetyl CoA will turn into citric acid
Citric acid goes through the cycle to form ATP, carbon dioxide, NADH and FADH2 (these two items hold high energy electrons that will be used in the next cycle)
Electron Transport ChainNADH and FADH2 is
passed to this stage in the membrane of the mitochondria
The electrons that are in these two molecules are passed along the carrier proteins in the membrane
Water will form at the end of this chain
Kreb and electron transport chain produce 36 ATP per one molecule of glucose
We don’t always consume glucose so how do we make ATP?Complex carbohydrates are broken down
into glucose.Lipids and proteins can be broken down
into molecules that enter the Kreb cycle and electron transport chain
Energy and exerciseQuick energy
Enough ATP for a short timeRest of time ATP is produced by lactic acid
fermentationAfter race, heavy breathing is used to increase
oxygen to repay the oxygen debtLong term energy
For exercise that is 90 seconds or longer, body relies on cell respiration
Use stored energy in the form of glycogenBody will begin to break down other stored
molecules like fat