Cellular Respiration

Cellular respiration__ as an exothermic reaction which occurs continuously in living cells to release energy for metabolic processes__, including aerobic and anaerobic respiration.

The process of respiration is a chemical reaction that breaks down nutrients in order to release energy to the organism.

Humans require energy for:

  1. Contracting our muscles
  2. Making protein molecules
  3. Cell division to take place (for growth and repair)
  4. Active transport
  5. Transmitting nerve impulses
  6. The maintenance of constant body temperature

We get this energy from the food that we eat, and the useful molecules are absorbed into our bloodstream.

__Glucose __provides a lot of chemical energy, and it can be found in a lot of the food that we eat.

There are 2 types of respiration:

Respiration, figure 1

  1. Aerobic respiration__ __requires oxygen in order to break down the glucose to create more energy
  2. Anaerobic respiration__ __does not require oxygen to break down the glucose, but creates less energy.

Aerobic Respiration

Aerobic respiration__ __releases a lot more energy in cells when food is broken down in the presence of oxygen.

Glucose + Oxygen → Carbon dioxide + Water (+ Energy)

Carbon dioxide and water are also produced during the process of aerobic respiration.

Anaerobic Respiration

Anaerobic respiration__ __releases _less energy _in cells when food is broken down without oxygen.

When humans are exercising, they would benefit from aerobic respiration as they are releasing more energy. However, as the oxygen levels decrease, humans would then switch to anaerobic respiration.

Glucose → Lactic Acid + Water ( + Energy)

The formation of lactic acid __in the body causes the cramp that people feel when they’re doing exercise. There is not enough blood flowing through, therefore __anaerobic respiration has to take place. In order to get rid of the cramp, more oxygen is needed in the body so that the body can switch back to aerobic respiration.

Anaerobic respiration can also take place in yeast, where glucose is broken down to create ethanol, carbon dioxide and energy.

Glucose → Ethanol + Carbon Dioxide (+ Energy)

Calculating Cardiac Output

Heart rate, stroke volume and cardiac output can be calculated with the following equation:

cardiac output = stroke volume × heart rate

  1. Cardiac output__ _is the amount of blood that can be pumped by the heart per minute_.
  2. Heart rate__ _is _the most useful indicator of whether the heart is functioning normally. The more exercise you do, the higher the heart rate is so that more blood can be pumped around the body, so that the right molecules can be transported to the blood.
What are the two types of respiration?
Your answer should include: Anaerobic / Aerobic
What is the equation for anaerobic respiration in yeast?
Your answer should include: Glucose / Ethanol / Carbon Dioxide / Energy
Which type of respiration requires oxygen?