#97 Summary of Energy and Respiration

1 Organisms must do work to stay alive. The energy input necessary for this work is either light, for photosynthesis, or the chemical potential energy of organic molecules. Work includes anabolic reactions, active transport and movement. Some organisms, such as mammals and birds, use thermal energy released from metabolic reactions to maintain their body temperature. 

#96 Using respirometers

A respirometer is a device used to measure the rate of respiration of a living organism by measuring its rate of exchange of oxygen and/or carbon dioxide. They allow investigation into how factors such as age, chemicals or the effect of light affect the rate of respiration.

#95 Rice adaptation for growing with its roots submerged in water

There are many varieties of rice and they differ in their water requirements. Most of the rice in south-east Asia is grown in unusual conditions for a cereal plant. It is grown partly submerged in water in paddy fields.

#94 Structure and function of the mitochondrion

The mitochondrion is a power plant and industrial park of the cell where energy stored in the bonds of carbohydrates is converted to a form more useful to the cell (ATP) and certain essential biochemical conversions of amino acids and fatty acids occur.

#93 Respiratory substrates, Respiratory quotions

A respiratory substrate is a molecule from which energy can be liberated to produce ATP in a living cell. Glucose is not the only respiratory substrate. All carbohydrates, lipids and proteins can also be used as respiratory substrates.

#92 ATP yield in aerobic and anaerobic respiration

Only small amounts of ATP are produced when one glucose molecule undergoes anaerobic respiration. This is because only glycolysis is completed. The Krebs cycle and oxidative phosphorylation, which produce most ATP do not take place.

# 91 Anaerobic respiration - Ethanol and Lactate pathways

Anaerobic respiration is a type of respiration that does not use oxygen. It is used when there is not enough oxygen for aerobic respiration.

# 90 Oxidative phosphorylation and Electron transport chain

In the final stage of aerobic respiration, oxidative phosphorylation, the energy for the phosphorylation of ADP to ATP comes from the activity of the electron transport chain (ETC). Oxidative phosphorylation takes place in the inner mitochondrial membrane, the cristae.

#89 The Krebs cycle

The Krebs cycle occurs in the matrix of the mitochondrion and is the aerobic phase and requires oxygen.

This is also known as the citric acid cycle or the tricarboxylic acid cycle.

#88 Aerobic respiration, Link reaction

If oxygen is available, each pyruvate now moves into a mitochondrion, where the link reaction and the Krebs cycle take place. During these processes, the glucose is completely oxidised.

#87 Respiration, Glycolysis

Respiration is the oxidation of energy-containing organic molecules. The energy released from this process is used to combine ADP with inorganic phosphate to make ATP.

#86 Energy and ATP

All living organisms need a continuous supply of energy to maintain their metabolism. They must absorb either light energy in photosynthesis or chemical potential energy to do the work necessary to stay alive.

#85 Energy and Respiration - Syllabus 2016 - 2018

12.1  Energy

12.2  Respiration