Respiration

what is aerobic response?

an exothermic reaction in which glucose reacts with oxygen to release energy which can be used by cells

what is the word equation for aerobic respiration

glucose + oxygen → carbon dioxide + water (+energy)

what is the symbol equation for aerobic respiration

C6 H12 O6 +6(O2) → 6(CO2) + 6(H2O) (+energy)

where dos aerobic respiration take place

mitochondria

why do organisms require the energy released by respiration

• synthesis of larger molecules

• muscle contraction

• maintenance of body temperature

• active transport

what is anaerobic respiration

an exothermic reaction in which glucose is broken down to release energy in the absence of oxygen

what is the word equation for anerobic respiration

glucose → lactic acid (+energy)

why is anaerobic respiration less efficient then aerobic respiration

glucose is not completely broken down, so less energy is transferred

why can anaerobic respiration lead to muscle fatigue

the product of anaerobic, lactic acid, builds up in muscles, preventing efficient contraction

what is oxygen debt

the amount of oxygen needed to convert lactic acid back into glucose after anaerobic respiration

what is fermentation

a type of anaerobic respiration that occurs in yeast cells

what is the word equation for fermentation

glucose → ethanol + carbon dioxide (+energy)

why is the fermentation reaction important

it is used in the production of bread and alcoholic drinks

what are the differences between aerobic and anaerobic respiration

• aerobic requires oxygen, anaerobic does not

• aerobic produces CO2 and water, anaerobic produces lactic acid or ethanol + CO2

• aerobic transfers a greater amount of energy

how do muscles store glucose

as glycogen

what changes take place when muscular activity increases in the body

• heart rate increases and arteries dilate - increases flow of oxygenated blood muscles

• breathing rate increases and breathing is deeper - increases the rate of gaseous exchange

• stored glycogen is converted back into glucose

how is lactic acid transported away from the muscles

blood flow through the muscles transport lactic acid to the liver, where it is oxidised back to glucose

what is metabolism

the sum of all the reactions that take place in a cell or an organism

how do cells use the energy transferred by respiration

to continuously carry out enzyme controlled processes which lead to synthesis of new molecules

give examples of metabolic reactions

• glucose into starch/glycogen/cellulose

• glycerol and fatty acids into lipids

• glucose and nitrate ions into amino acids

• photosynthesis

• respiration

• breakdown of excess proteins into urea