Respiration Flashcards
Respiration is a exothermic/endothermic reaction
exothermic
Transfers energy to the environment (usually in the form of heat)
Respiration -
chemical reaction in which living cells use glucose (food) to release energy in the form ofATP
Word equation for aerobic respiration
Glucose + oxygen —> carbon dioxide + water
What do organisms need energy for:
- chemical (anabolic )reactions to build larger molecules from smaller ones
- animals: enable muscles to contract i.e. for movement
- mammals + birds: maintain steady body temperature
What is glucose stored as?
glycogen- glucose bonded in chains
When does anaerobic respiration occur in muscles?
When there is insufficient oxygen available to meet the oxygen demand
Anaerobic respiration is the ……….
Incomplete oxidation of glucose
(As a result less energy transferred to the environment as glucose not fully oxidised)
Word equation for anaerobic respiration in muscles cells:
Glucose —> Lactic Acid
Name 4 key differences between aerobic respiration and anaerobic respiration:
- less energy released by anaerobic respiration
- no oxygen used in anaerobic respiration
- lactic acid formed as a waste product in anaerobic respiration
- no carbon dioxide produced in anaerobic respiration
What is muscle fatigue
- Occurs when lactic acid builds up in muscles due to oxygen debt (when there is a high level of anaerobic respiration e.g. after vigorous exercise)
- causes muscles to stop contracting efficiently
What happens to the lactic acid after it is produced?
- lactic acid diffuses out of muscles into plasma
- plasma carries lactic acid to liver
- in liver 1/5 of lactic acid converted back to glucose and 4/5 converted to glycogen
Where does aerobic respiration mostly occur
Mitochondria
Name 3 effects that exercise has on out body:
- Increased heart rate
- Increase breathing rate + depth (volume of each breath increases)
- Vasodilation (get wider) of the arterioles supplying the skeletal muscles and surface of skin occurs
What are the reason heart rate increases during exercise?
- more blood to muscles
- more oxygen to muscles
- more glucose to muscles
- more aerobic respiration
- more energy released
- more carbon dioxide removed from muscles into lungs for exhalation
- more lactic acid removed from muscles
What are the reasons breathing rate and depth increases during exercise?
- more oxygen in
- muscles respire more
- muscles need more energy but produce more CO2
- remove more CO2 from muscles to lungs for exhalation