Cell Respiration
Overview of Cell Respiration:
Cell Respiration is how cells get the energy out of molecules like glucose.
Every cell is a living thing because it has energy. The energy is used continually for a living thing to be able to carry out life processes. (MRS GREN)
The source of energy for all living cells is glucose. The glucose molecule has a lot of energy locked inside the chemical bonds. When the bonds are broken the energy is released.
Cells continually burn glucose, releasing CO2, water and energy. The energy is transferred into a molecule called ATP
Most of the process happens in organelles which are called Mitochondria (Mitochondrion - singular)
Cells which have a high energy demand have a lot of mitochondria eg muscle cells. Cells which do not need much energy such as fat cells or storage cells have very few mitochondria. Mitochondria have their own genetic material call mtDNA and can replicate themselves inside the cell if needed. (Part of getting fit!! - your muscle cells will make more mitochondria!!)
Every cell is a living thing because it has energy. The energy is used continually for a living thing to be able to carry out life processes. (MRS GREN)
The source of energy for all living cells is glucose. The glucose molecule has a lot of energy locked inside the chemical bonds. When the bonds are broken the energy is released.
Cells continually burn glucose, releasing CO2, water and energy. The energy is transferred into a molecule called ATP
Most of the process happens in organelles which are called Mitochondria (Mitochondrion - singular)
Cells which have a high energy demand have a lot of mitochondria eg muscle cells. Cells which do not need much energy such as fat cells or storage cells have very few mitochondria. Mitochondria have their own genetic material call mtDNA and can replicate themselves inside the cell if needed. (Part of getting fit!! - your muscle cells will make more mitochondria!!)
Mitochondria: these are organelles which carry out the main steps in cell respiration; some steps happen in the cytoplasm
Aerobic respiration: WITH OXYGEN
Glucose and Oxygen enter the cell - by diffusion.
Step 1: Glycolysis:
•Happens in the cytoplasm
•Costs energy (ATP used)
•Splits the glucose ring in half to make 2 molecules
•Molecules made are Pyruvic Acid
•Does not need O2
•Makes energy (ATP made)
Step 2: Krebs cycle/Citric Acid cycle
•Happens in the mitochondrial matrix space
•The pyruvate molecules are broken down to Carbon dioxide and hydrogen
•Co enzyme A is needed
•A lot of energy is released which activates Hydrogen atoms
Step 3: The Respiratory Chain/ electron transfer chain
•requires O2
•Activated Hydrogens move out of the matrix into the space between the membranes (Cristae)
•Hydrogen bonds with Oxygen to make water
•the excites atoms which causes the formation of ATP from ADP
•A large number of ATP molecules are made (38)
Energy from the glucose molecule is now packaged into small units of ATP.
The ATP moves around the cell by diffusion, automatically going to areas of the cell where there is a low concentration of ATP.
The low concentration is caused by cell reactions which need energy
ANAEROBIC RESPIRATION; NO OXYGEN
Step 1: Glycolysis as above
Step 2:•Anaerobic Pathway
- Happens in the cytoplasm as well
- •1. Alcohol (Fermentation) & CO2 - yeasts & some bacteria
- •2. Lactic Acid - muscles in animals
The energy is used to make ATP
Anaerobic Respiration is much less efficient as the Pyruvic acid is not broken down completely.
An 8 minute clip explaining this process. All from the Amoeba Sisters from Texas!!