Respiration Flashcards
respiration
the breakdown of food (carbs) to release energy
respiration formula
c6h12o6 + 6o2 —-enzymes—> 6co2 + 6h2o + energy
aerobic respiration
the breakdown of food in the presence of oxygen to release energy
anaerobic respiration
the breakdown of food with no oxygen to release energy
fermentation
another term for anaerobic respiration in yeast cells (no oxygen required)
applications:
baking, brewing
fermentation in muscle
glucose –> lactic acid + very little energy
fermentation in yeast
glucose –> ethanol + carbon dioxide + very little energy
biotechnology
the use of living things (cells and enzymes) to manufacture useful products
bioreactor
a vessel in which living cells, organisms or yeast are placed in to make a useful product
immobilised cells
cells that are attached to an inert substance by physical or chemical means
stage 1 glycolysis
location: cytosol
conditions: anaerobic
amount of energy released: very little (partial break down of glucose)
- break down of glucose into 2 pyruvates (3 carbon molecules)
- energy is released, picked up by ADP+P to form ATP+ water
- 2e- and H+ released, picked up by NAD+ to form NADH
fate of pyruvate when oxygen is present
taken to mitochondria
loses a co2
loses 2e- and H+ picked up by NAD+ to form NADH
broken down to 2 carbonacetyl group: acetyl coenzyme A
fate of pyruvate when oxygen is not present
remains in cytosol
in yeast cells: pyruvate is converted to ethanol and carbon dioxide
in animal cells: pyruvate is converted to lactic acid
stage 2 Krebs Cycle and electron transport chain
location: mitochondria
conditions: aerobic
amount of energy released: more than first stage
describe the Krebs Cycle
- acetyl group broken down to release carbon dioxide, hydrogen ions, electrons
- carbon dioxide released as waste gas
- NADH produced when 2e- and H+ are picked up by NAD+
- ATP produced when energy is lost and picked up by ADP+P
describe the electron transport chain
- NADH from krebs broken down to hydrogen ions and electrons
- electrons lose energy as they move through different carriers, energy released by e-
products of electron transport chain
energy released forms ATP
2H+ ions and 2e- combine with oxygen to form water
to prepare and show the production of alcohol by yeast
control: no yeast in glucose solution
- boil a glucose solution (creates anaerobic conditions)
- allow solution to cool
- add yeast
- add layer of oil
- attach airlock to conical flask
- add limewater to airlock (to show presence of carbon dioxide)
- leave both in a water bath at 30°
iodoform test
- filter solution
- add an equal volume of potassium iodine to filtrate- colour change : brown to colourless
- add sodium hypochlorite
- place in water bath at 50-60°
- allow to cool
pale yellow crystals = ethanol present
colourless to yellow = alcohol has been produced
