Cellular respiration Flashcards
Energy
That which is required to do work
Energy is required by organisms to do…
- growth
- cell division
- digestion
- movement
- transport substances in the body
- active transport against concentration gradients
The primary source of energy for life on earth
The sun
ATP
- Adenosine triphosphate
- energy carrier molecule for cells
Raw materials needed for cellular respiration
- Glucose
- Oxygen
Products of cellular respiration
- Carbon dioxide
- Water
- Energy (ATP formed)
Equation for the process of cellular respiration
Place where cellular respiration occurs in most cells
Mitochondria
The inner folds of the mitochondria
Cristae
The jelly like substance inside the mitochondria
matrix
Reason for the inner folded cristae of a mitochondrion
- Increase surface area
- So that more reactions that take place on this surface can occur
Two types of cellular respiration
- Aerobic (requires oxygen)
- Anaerobic (does not require oxygen)
Three phases of aerobic respiration
- Glycolysis
- Krebs cycle
- Oxidative phosphorylation
Where glycolysis occurs
In the cytoplasm just outsside the mitochondrion
What occurs during glycolysis?
- Glucose broken down
- Two pyruvic acid molecules formed
- Energy rich H-atoms released
- Small amount of ATP formed
What carries the energy rich H-atoms during aerobic cellular respiration?
Coenzymes (hydrogen carriers)
Where the Krebs cycle occurs
Inside the mitochondrion
What occurs during the Krebs cycle
- Pyruvic acid is broken down in the presence of oxygen
- Energy rich H-atoms are released
- Carbon dioxide is formed
Where oxidative phosphorylation occurs
On the inner folds of the cristae
What occurs during oxidative phosphorylation?
- Energy rich H-atoms are carried to a hydrogen transfer system by coenzymes
- Eah time they are passed to the next hydrogen acceptor energy is released
- The energy is used to form ATP
- Oxygen is the final hydrogen acceptor, forming water.
Anaerobic respiration
- Respiration in the absense of oxygen
- Only glycolysis occurs
- Only a small amount of energy is released
Anaerobic respiration in the muscles (lactic acid fermentation)
- During vigorous exercise
- Not enough oxygen present in the muscles
- Only glycolysis takes place
- Pyruvic acid is formed
- Pyruvic acid is converted into lactic acid
What happens to lactic acid in the muscles?
- It is toxic and leads to muscle stiffness and pain
- Oxygen is needed to convert to pyruvic acid
- Moderate exercise and stretching with deep breathing helps muscle stiffness
- With enough oxygen, aerobic respiration takes place and pyruvic acid enters the Kerbs cycle
Oxygen debt
The need for oxygen to get rid of lactic acid which accumulates in the cells
Alcoholic fermentation
- Only glycolysis occurs
- Pyruvic acid forms when glucose broken down
- Small amount of energy released
- Pyruvic acid is broken down forming carbon dioxide and ethanol (alcohol)
The microbe used mainly for anaerobic respiration in beer, wine and bread making
- Yeast cells
- (A type of fungi)
The microbe used to produce cheese, yogurt and some sour dough breads
Certain strains of bacteria
Four beer ingredients
- barley
- water
- hops
- yeast
Process of making beer
- Barley germinated then dried and chopped to form malted barley
- Malted barley mixed with water to dissolve sugars
- The liquid, called wort, is collected
- Hops are added (bitterness and flavour) and boiled
- Yeast is added and the mixture ferments
- The carbon dioxide give the beer bubbles and ethanol is formed
- The yeast cells sink to the bottom and the beer is cooled, filtered and bottled
The process of making wine
- Grapes are pressed
- Pulp (must) is forms which starts to naturally ferment
- Fermentation is continued with added yeast in vats
- The sugar is converted into ethanol and carbon dioxide
- The wine is filtered and then further fermented
- Stored in vats or barrels to age before being bottled
The process of baking bread
- Flour, water, salt and yeast are mixed
- The yeast feeds on the flour and forms ethanol and carbon dioxide
- The dough rises as the gluten in the dough forms bubbles of carbon dioxide
- The bread is baked and the ethanol evaporates and the yeast is killed.
The process of making cheese
- Lactic acid bacteria are added to milk
- The acid produced causes the milk to curdle
- Rennin is added to further clump the milk
- The whey is removed and the curds are compressed
- The cheese is allowed to age
Similarities between aerobic and anaerobic respiration
- Glucose is broken down
- Carbon dioxidde is released
- Energy is released
How aerobic respiration is different from anaerobic?
- It occurs with oxygen
- Products are carbon dioxide and water
- A much larger amount of energy is produced
- Takes also takes place inside the mitochondrion
How anaerobic respiration is different from aerobic?
- It occurs without oxygen
- Products are lacic acid or carbon dioxide and ethanol
- Only a small amount of energy released
- Only takes place in the cytoplasm
