2.8 Cell respiration Flashcards
What is cell respiration?
The controlled release of energy from organic compounds to produce ATP
What is the main organic compound used in cell respiration?
Carbohydrates (glucose)
Alongside carbohydrates what else is digested during cell respiration?
Lipids and proteins
What are the two types of cell respiration?
Anaerobic respiration and aerobic respiration
What does anaerobic respiration involves?
It involves the partial breakdown of glucose in the cytosol for a small yield of ATP
What does aerobic respiration utilise to do what?
Oxygen to break down glucose in the mitochondria for a larger ATP yield
What is the cell respiration equation?
Glucose + oxygen = carbon dioxide + water + atp
What does ATP stand for?
Adenosine triphosphate
What is ATP?
A high energy molecule that functions as an immediate source of power for cell processes
What does one molecule of ATP contain?
Three covalently linked phosphate groups
What does the three covalently linked phosphate groups do?
Store potential energy in their bonds
What happens when ATP is hydrolysed?
The energy stored in the phosphate bond is released to be used by the cell
What does cell respiration use energy from organic molecules to do?
Regenerate ATP from ADP + Pi
What do both anaerobic and aerobic respiration pathways begin with?
The anaerobic breakdown of glucose in the cytosol
What is responsible for the anaerobic breakdown of glucose in the cytosol?
Glycolysis
What does glycolysis break down and into what?
Glucose into two molecules of pryuvate
What else does pryuvate produce?
Hydrogen carriers from an oxidised precursor
A small yield of ATP
When does anaerobic respiration proceed?
In the absence of oxygen
What does anaerobic respiration not result in?
The production of any further ATP molecules
What is pyruvate converted into in animals?
Lactic acid (lactate)
What is pyruvate converted into in plants and yeasts?
Ethanol and carbon dioxide
What is the purpose of anaerobic respiration?
To restore stocks of NAD+
Why does anaerobic respiration restore stocks of NAD+?
So the organism can continue producing ATP via glycolysis
Is the conversion of pyruvate in animals/plants and yeast reversible?
Yes
What can be restored once oxygen is present?
Pyruvate levels
Why does muscle contractions require high levels of ATP?
Because the expend high amounts of energy
What happens to the cells energy demands when exercising at high intenisty?
They will exceed what the available levels of O2 can supply aerobically
When exercising at high intensity what does the body do to maximise ATP production?
Begin to break down glucose anaerobically
What leads to muscle fatigue?
An increase in the production of lactic acid
What happens when an individual stops exercising?
Oxygen levels will increase and lactate will be converted back to pyruvate
What can only be used to undergo anaerobic respiration?
Carbohydrates
When talking about exercise intensity, when will lactate levels increase?
At higher levels of exercise intensity
When talking about exercise intensity, what happens to the aerobic consumption of fats at high intensities?
It decreases
When talking about exercise intensity, what happens to the anaerobic consumption of sugars at high intensities?
It increases
Where does aerobic cell respiration take place?
In the mitochondrion
What does aerobic cell respiration require the presence of?
Oxygen
During aerobic respiration what is pyruvate broken down into?
Carbon dioxide and water
During aerobic respiration, what is produced and how much?
ATP (34 - 36 molecules)
What type of process is glycolysis?
Anaerobic
What does aerobic respiration consist of?
The link reaction, krebs cycle and the electron transport chain
Where does aerobic respiration begin?
With glycolysis in carbohydrates
What does fermentation involve?
The breakdown of carbohydrates in the absence of oxygen
In yeasts what does fermentation results in the production of?
Ethanol and carbon dioxide
What is used during food processesing?
Fermentation in yeasts
How is yeast fermentation used in bread?
Carbon dioxide causes dough to rise
The ethanol evaporates during baking
How is yeast fermentation used in alcohol?
Ethanol is the intoxicating agent in alcoholic drinks
What do bacterial cultures undergo to produce food products?
Fermentation
How are bacterial cultures used in yogurt and cheese?
Bacteria produces lactic acid anaerobically which modifies milk proteins to make yogurts and cheeses
What is a respirometer?
A device that determines an organisms respiration rate by measuring the rate of exchange of oxygen and carbon dioxide
What factors affect respiration rates?
Temperature
Hydration
Light
Age
Activity levels
How does an increase in carbon dioxide levels affect respiration and why?
Increases respiration as carbon dioxide is a product of aerobic respiration
How does a decrease in oxygen levels affect respiration and why?
Increases respiration as oxygen is a requirement of aerobic respiration
How does a respirometer work?
The living specimen is enclosed in a sealed container
How can carbon dioxide production be measured in respirometer?
With a data logger or by pH changes if the specimen is in water
When can oxygen consumption be measured as a change in pressure within the system?
When an alkali is included to absorb carbon dioxide
How can pressure change be detected in a respirometer?
With a data logger or via use of a u-tube manometer
