Anaerobic and aerobic cell respiration

what and where do all forms of respiration start with

glycolysis in the cytoplasm

If oxygen is present…

aerobic respiration occurs

If oxygen is not present…

pyruvate is converted to lactic acid = anaerobic respiration

What happens after glycolysis (anaerobic)

pyruvate is broken down without oxygen

what is the ATP yield

small but produced quickly

where does this help in the situation

• short and rapid burst of ATP

• oxygen supplies run out in respiring cells

• oxygen-deficient environments (e.g. waterlogged soil)

what type of activities require anaerobic respiration

high-intensity exercises (boxing, sprinting, weight lifting)

why do such activities use anaerobic respiration

• not enough time to deliver oxygen to cells for aerobic repsiration

• supply of energy needs to be fast and quickly available

in high-intensity exercises, which metabolic pathways are primarily used?

glycolysis followed by anaerobic (lactic acid) fermentation, with little aerobic respiration.

what by-product accumulates during anaerobic glycolysis

lactic acid

what happens when lactic acid accumulates in the muscles

decreases pH and inhibits actin-myosin interactions

what happens after glycolysis (aerobic)

pyruvate is absorbed by the mitochondria

what happens to the pyruvate in the mitochondria

reduced into carbon dioxide, water and 36-38 molecules of ATP

step 1 - aerobic

glucose from food/oxygen is transported via the bloodstream to be absorbed into the cytoplasm

step 2 - aerobic

(in cytoplasm) glucose is turned into pyruvate during glycolysis; small amout of ATP is produced

step 3 - aerobic

pyruvate is transported into the mitochondrion, where it is broken down; large amount of ATP

step 4 - aerobic

carbon dioxide is a waste product and diffuses into the bloodstream to be later exhaled from the lungs