mrs muswells increadible biology notes!!!!

HideShow resource information
Preview of respiration

First 96 words of the document:

What do organisms use energy for:
Movement ­ e.g. breathing, running, thinking,
growing towards the light (cress seedlings),
flowering, seed production
Generating heat energy ­ for warmblooded
animals, e.g. birds and mammals
Where does the energy come from:
The breakdown of food molecules ­ carbohydrates, fats and
sometimes proteins (e.g. in cats)
Food is a source of CHEMICAL ENERGY.
Respiration is the breakdown of glucose to release
energy in living organisms.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Living organisms, both plants and animals, carry
out respiration 24 hours per day, 7 days per week,
i.e. all the time.
Sources of Chemical Energy
Plants are the ONLY organisms which can convert solar
energy into chemical energy.
All organisms on the planet therefore are either plants which
produce their own carbohydrates (then converted into fats
and proteins) by PHOTOSYNTHESIS.......
Or animals that feed on plants, or carnivores that prey on
these herbivores.…read more

Page 3

Preview of page 3

Here's a taster:

C6H12O6 +6O2 6CO2 + 6H20 with the
release of a
high level of energy
· recall the word equation for anaerobic respiration in plants
and in animals (B2.26).
Anaerobic Respiration ­ the breakdown of glucose
without oxygen. Because of this, the glucose is only partly
broken down, so far less energy is released.…read more

Page 4

Preview of page 4

Here's a taster:

In Yeast
­ anaerobic respiration (fermentation) is normal for yeast
Glucose >ethanol + carbon dioxide
with the release of a
small amount of energy
· describe the differences between aerobic and anaerobic
respiration (B2.…read more

Page 5

Preview of page 5

Here's a taster:

How did we show that carbon dioxide is given out
during respiration.
There are 2 Carbon dioxide Indicators:
Limewater clear + colourless >cloudy and white (the
gas must be bubbled through the solutions)
Bicarbonate indicator (for when we are immersing living
organisms eg snails)
Red and clear > yellow and clear.
Plants ­ do 2 things!
respire 24/7, taking up oxygen and releasing carbon
Additionally, during hours of daylight, they
photosynthesize which uses carbon dioxide and
generate oxygen.…read more

Page 6

Preview of page 6

Here's a taster:

At dawn and dusk (low light levels) the oxygen generated by
photosynthesis is sufficient for respiration needs.........and
the CO2 released by respiration is sufficient for
Experiments using bicarbonate indicator.
Specimen Tubes containing Bicarbonate Indicator
after being under light for 40 minutes.
From left to right:
1. Indicator with snails only .
2. Indicator with Elodea only.
3. Indicator with snails and Elodea.
4. Control indicator for colour comparison.
Specimen Tubes containing Bicarbonate Indicator
left in the dark for 40 minutes.…read more

Page 7

Preview of page 7

Here's a taster:

From left to right:
1. Indicator with snails only .
2. Indicator with Elodea only.
3. Indicator with snails and Elodea.
4. Control indicator for colour comparison.
As you can see, where plants have light, they photosynthesise
as well as respire. Because this photosynthesis removes
more carbon dioxide than the respiration adds, the indicator
changes colour from red (CO2 level at 0.04% ) to purple (CO2
level less than 0.…read more

Page 8

Preview of page 8

Here's a taster:

CO2 ) to yellow (CO2 greater than 0.04%).
Other practicals
Collecting carbon dioxide
Place yeast solution in a test tube. Incubate at 35°C.
Place a balloon over the top of the test tube. The carbon
dioxide gas will collect in the balloon.…read more

Page 9

Preview of page 9

Here's a taster:

The apparatus above shows a simple respirometer. This
allows us to measure the uptake of OXYGEN as the organisms
in the beaker respire. Here, they are mealworms ­ they could
just as easily be germinating peas, maggots or locusts.
Water bath ­ to maintain a constant temperature for the
mealworms (you choose the range of temperatures as
Remember that respiration also generates a great deal of
heat energy which could introduce a new variable and skew
your results.....…read more

Page 10

Preview of page 10

Here's a taster:

This apparatus only measures the change in the volume of
gas ­ which of course will not alter.
By removing the carbon dioxide gas as it is produced, there
will be a lower volume of gas present.
This reduction creates an area of lower pressure in the
capillary tube (i.e. the same space now contains less gas
molecules so the pressure falls).…read more


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »