B4

RESPIRATION

Respiration = RESPIRATION is a series of chemical recations that RELEASE ENEGRY by breaking down large FOOD MOLECULES. 

The enrgy released by respiration is used to power some of the chemical reactions that happen in cells, such as:

Movement-  Energy is needed to make mucles contract

 Active Transport- This process uses energy to move substances in and out of cells

Synthesis of large molecules-  Joining smaller molecules together requires energy

eg. Glucose is  JOINED together to make starch/cellulose in plant cells

eg. In plant and animal cells and microorganisms, glucose and nitrogen are JOINED together to make amino acids which JOIN together to make proteins                                                                                         

-Aerobic Respiration= WITH oxygen

-Releases more energy per glucose molecule than anaerobic respiration

-Type of respiration that we use most of the time

-Takes place in animal and plant cells and SOME microorganisms

-Anaerobic Respiration = WITHOUT oxygen

- Releases less energy per glucose molecule than aerobic respiration

Happens in human cells when we exercise as the body can't supply enough oxygen to the muscle cells through aerobic respiration so they respire anaerobically instead

Happens in plant cells when the soil where a plant is growing becomes waterlogged and there is oxygen available for the roots so the root cells respire anaerobically

Happens in bacteria cells when bacteria gets under our skin through wounds and there is very little oxygen under the skin so bacteria respires anaerobically

In animal and some bacteria cells anaerobic respiration produces lactic acid

In plant cells and some microorganisms anaerobic respiration can produce ethanol and carbon dioxide

Fermentation =  when microorganisms break down sugars into other products as they repsire anaerobically

Humans use fermentation to make lots of things:

BIOGAS- 'A fuel used for things like heating and lighting'                                                                          Lots of different microorganisms are used to produce biogas because they ferment                        plant and animal waste, which contains carbohydrates.                                                              The biogas they produce is mainly made of methane and carbon dioxide

BREAD - Bread is made using yeast, which ferments the carbohydrates in the flour and releases                 Carbon Dioxide which is what causes the bread to rise

ALCOHOL- Yeast ferments sugar to form alcohol                                                                                        The sugar used in alcohol production comes from grapes and barley (wine & beer)

Aerobic Respiration:

Anaerobic Respiration in ANIMAL CELLS

Glucose                           Lactic Acid + ENERGY

Anaerobic Respiration in PLANT CELLS

Glucose      Ethanol + Carbon Dioxide + ENERGY