2.f. Respiration

Types of respiration

Two main types of respiration, aerobic and anaerobic

2.35 Anaerobic respiration

.- Anaerobic: without "air". AKA fermentation .-Release energy from glucose molecule but without O .-The glucose molecule is only partly broken down → less energy released: 150 kJ per mole

2.33 Cellular Respiration

.- The release of energy from the chemical bonds in food molecules such as glucose. .-ONLY inside cells. ALL cells. .-Every living cell carry out cellular respiration in MITOCHONDRIA.

2.34 Aerobic Respiration

.-Aerobic means "Air" .-Aerobic respiration is cellular respiration using O. .-supplies most of the energy that plants and animals cells need

For what is used energy from cellular respiration?

.-All life processes .-e.g. keep warm, contract muscles, build up large molecules, active transport

2.36 Word equation for aNAerobic respiration in animal

.-Glucose is broken down to lactic acid. .-glucose → lactic acid (+ energy)

Respiration is NOT cellular respiration

.-Respiration In conversation, usually means breathing. .-Cellular Respiration releases energy from digested and absorbed food molecules such as glucose.

When is used aNAerobic respiration?

.-Used when not enough O for aerobic respiration. e.g: diving animals (whale), muscle cells+vigorous exercise .-Even when a muscle cell is respiring anaerobically, AEROBIC respiration takes places using all available O

2.36 Word equation for aNAerobic respiration in plants

.-glucose → ethanol + CO₂ (+energy)

ATP

Adenosine triphosphate (ATP). ATP is where the energy is stored for use later on by the body.

2.34 Describe differences between aerobic and anaerobic respiration

Aerobic Anaerobic 1.-Oxygen Needed Not needed 2.-Glucose breakdown Complete Incomplete 3.-End product(s) CO₂ and H₂O Animal cells: lactic acid. Plant cells and yeast: carbon dioxide and ethanol 4.-Energy released Large Small Aerobic: 19 times more energy than anaerobic from the same amount of glucose.

Mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production Cells where lots of respiration is carried out (eg. muscle cells) have MANY more mitochondria.

2.35 Balanced chemical equation for aerobic respiration

C6H12O6 + 6O2 →6CO2 + 6H2O + 2900 kJ/mol Many of the chemical bonds in glucose is broken down by O to release energy . Waste products: CO₂ and H₂O Around 2900 kJ of energy is released when one mole of glucose is broken down. This energy used to make a molecule called ATP

EPOC

Excess Post-exercise Oxygen consumption There is a build-up of lactic acid in the muscles during vigorous exercise. The lactic acid needs to be oxidised This causes an oxygen debt (EPOC) - that needs to be 'repaid' after the exercise stops →why we keep on breathing deeply for a few minutes after we have finished exercising.

2.35 Word equation for aerobic respiration

Glucose + Oxygen → Carbon dioxide + Water + Energy .-Oxygen from the air (except some O come from photosynthesis) .-CO₂: released into the air .-H₂O: used in te body or excreted through the kidneys .-Each step catalysed by a different ENZYME

Photosynthesis and Aerobic respiration

Photosynthesis: (sunlight Energy) Carbon dioxide + Water --------→ Glucose + Oxygen aerobic respiration (2.35) works in the opposite way to photosynthesis.

Anaerobic respiration in plant cells

plant cells not getting enough O. e.g. 1.-inside a germination seed there is little O 2.-fungi: yeast in bread → CO₂ bubbles in dough