Respiration

Front

why do living organisms respire?

Back

living organisms respire because they need energy to move, grow, excrete, reproduce and maintain themselves.

main source of energy is the sun, plants convert light into glucose/chemical energy during photosynthesis which they store i the form of organic molecules. this energy is transferred to other orgnaisms via feeding. to use the energy stored in food, organims break doen the food molecules via oxidation to relaase energy, this is called a porecces called respiration

photosyntehitc organisms repsire to ocidise glucose to release neergy . for cells to use

Front

what are some process that are driven by the energy released during repsiration

Back

1. 1. anabolic reactions --> synthesis of proteins (larger molecules built from

2. 2smaller ones ei)

3. 2: active transport like absorption of glucose in the samll intestines/mineral ions in root hairs

4. 3: movement (contract or relax muscles)

5. 4: maintainence of body temperature

Front

what is aerobic respiration?

Back

aerobic respiration is the oxidation of glucose in the presence of oxygen with the release of large amounts of energy

--> during this process, carbon dioxide and water are released as waste products

--> the preferred respiratory substrate ( the molecule being oxidised to release energy during cellular respitration) is glucose ( its readily availble, quick oxidation)

--> in eukaryotes, most of the respiration takes place in the mitochondria

glucose (c6h1206 ) + oxygen (602) --> large amount of energy + carbon dioxide (6c02) + water (6h20)

Front

what is anaerobic repsiration and where does it occur

Back

1. anaerobic respiration is the breakdown of food substances int he absence of oxygen with the relaease of a relatively dmall amount of energy

it occurs n certain body cells like the muscles, and the microorganisms

Front

xplain anaeraboic repsiration in yeast

Back

1. 1. in yeast (unicellular fungi ), anaerobic respiration is called alcoholic fermentation.

2. yeast anaerobically respire to breakdown glucose into ethanol, carbon dioxide and small amount of energy

3. glucose --> co2 + ethanol +small amount of energy

ethanol is accumulated in the medium around the cells until the conc of ethanol rises to a level that prevents further fermentation as yeast are killed. (anaerobic respiration stops)

Front

explain anaerobic respiration in skeletal muscles

Back

1. 1. during strenuous exercise --> muscles contract more vigorously for faster movement --> this increases energy demand in the muscles

2. 2: the heart rate and the breathing rate increase to increase rate of respiration to increase amount of energy being released.

3. 3: when the heart rate and breathing rate increase, it enables the increase in rate of oxygenation of blood at the lungs, increased rate of transport of glucose and oxygen to the muscles, and increased rate of removal of carbon dioxide produced (during areobic reps)

4. 4: however if the increased uptake of oxygen is unable to meet the demand demand in the muscles, anaerobic respiration takes place to release the additional energy required for increased muscular contraction

5. 5: during anerobic respiration, it causes the accumulation of lactic acid in the muscles which can lead to fatigue

6: after the exercise has ended, the breathing rate and the heart rate remain high , 1: as lactic acid is being sent to the liver to be oxidised (02 still required) into carbon dioxide and water, and 2: some of the lactic acid is being converted to glucose to be stored as glycogen later in the liver and msucles

7: therefore, the additional oxygen required to oxidise the lactic acid in the liver is called as oxygen debt (hecne br and hr still high)

8: Heart rate and breathing rate only return back to normal once oxygen debt has been paid off and there is no mroe ie all lactic acid has been oxidised

when anaeriobic repsiration is occuring, aerobic repsiration stil ooccirs

Front

aerobic resp vs anaerobic resp

Back

during aerobic resp, o2 presence is required, co2 and h20 are the byproducts, and releases all available energy

during anaerobic resp, o2 presence not there, co2 and ethanol in yeast, lactic acid in mammals, releases less energy

Front

how to measure rate of respiration

Back

1. use a respirometer which measures the amount of o2 used by living organisms

2. 1--> the bottom of the test tube contains soda lime/sodium hydroxide which absorbs carbon dioxide present in the test tube and released by the living organism

3. 2 --> during respiration, organism takes in oxygen and gives out co2 which is absorbed by the soda lime

4. 3--> this results in the decrease in volume and pressure of air int he test tube, causing the colour liquid to move towards the organism

5. 4--> volume of oxygen used = distance moved by the colour liquid for a fixed duration

Front

what are the parts of the respiratory system

Back

1. 1. in the upper respiratiory tract, external nostril, nasal pasasges, pharynx, larynx

2: lower respiratory tract, trachea, bronchi, bronchioles, cluster of alveoli, int and ext intercoastal muscles, diaphragm

Front

desrcibe the larynx

Back

the larynx is the voice box, it contains the vocal chords, and is the air passage for sound porduction