b9 respiration triple

based on the AQA specification post 2018

cellular respiration

exothermic reaction that occurs in cells continuosly where the energy transferred provides the energy needed for living processes

how can respration occur?

aerobically presence oxygen

anaerobically absences of oxygen

aerobic respiration

chemical reaction that occurs in the presence of oxygen releasing energy.

. energy

glucose + oxygen → carbon dioxide + water

C6H12O6 + 602 → 6CO2 + 6H2O

respiration must occur continuosly unlike photosynthesis and does requireenergy to start the reaction

what processes use respiration

movement

reproduction

sensitivity

nutrition

excretion

growth

chemical reactions to build larger molecules

keeping warm

what does aerobic respiration show

energy transferred by light is convertedinto a chemical store of energy and is then released by respiration

anaerobic respiration

occurs in the absence of oxygen typically during oxygen damanding exercise i.e running

glucose→ lactic acid

a build up of lactic acid cases muscles fatigue and cramping . 5% of total energy is released during anaerobic respiration

oxygen debt

temporary shortage of oxygen in respiring tissues and organs.folowed by heavy breathing to replenish oxygen

oxidation

any reaction which a substance gives up electrons as when reacting with oxygen or the gain of oxygen

lactic acid + oxygen → carbon dioxide + water

lactic acid diffuses from a high to low concentration in the blood and then to the liver .in the liver it is converted into glucose via oxidation

anaerobic respiration in plants

glucose → ethanol and carbon dioxide

other wise known as fermentation

why is anaerobic respiration important

economically important for producing bread and alcohol

metabolism

the sum of all chemical reactions in the body whichare catlyzed by enzymes.

breakdown reactions

do not require lots of energy

e.g

protein breakdown:

into amino acids diffuse into blood and form urea and excreted by kidneys when in excess

amino acid breakdown:

liver enzyem removes amine gorup which breaks down the acid into urea

synthesis reactions

making larger molecues and requiring lots of energy

i.e

glucose rections-glucose is converted into insoluble starch which is stored or converted in cellullose for cell walls. animals convert glucose into glycogen stored in the liver .

making lipids- use to make cell mambranes and as a chemical store of energy

protein synthesis- glucose + nitrate ions to make amino acids and fold into specific proteins

response to exercise

During exercise the human body reacts to the increased demand for energy. The heart rate, breathing rate and breath volume increase during exercise to supply the muscles with more oxygenated blood. If insufficient oxygen is supplied anaerobic respiration takes place in muscles. The incomplete oxidation of glucose causes a build up of lactic acid and creates an oxygen debt. During long periods of vigorous activity muscles become fatigued and stop contracting efficiently. AT 1, 3, 4 Investigations into the effect of exercise on the body. (HT only) Blood flowing through the muscles transports the lactic acid to the liver where it is converted back into glucose. Oxygen debt is the amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells.