Cambridge IGCSE Biology (Section 4- Respiration and Gas Exchange) Mind Map on Section 4- Respiration and Gas Exchange, created by beccalaw7 on 11/06/2014.
Word Equation= Glucose + Oxygen --> Carbon Dioxide + Water
Symbol Equation= C6H12O6 + 6O2 --> 6CO2 + 6H2O
Anaerobic Respiration in Animals
Without oxygen
Glucose --> Lactic Acid
When exercising and your muscles ache, it is
the build up of lactic acid you are feeling
Anaerobic Respiration in Plants
Without oxygen
Glucose --> Ethanol + Carbon Dioxide
Fungi like yeast do anaerobic
respiration, so we use it to make beer
RESPIRATION IS NOT BREATHING IN AND OUT!!
RESPIRATION IS THE PROCESS OF
RELEASING ENERGY FROM
GLUCOSE, WHICH HAPPENS
CONSTANTLY IN EVERY LIVING
CELL
Gas Exchange in Plants
Plants exchange gases by diffusion
When plants photosynthesise they use CO2 from
the atmosphere and produce O2 as a waste
product
Therefore, when plants respire they use O2 and produce
CO2 as a waste product
When a plant is photosynthesising it uses up lots of CO2 so
there's not a lot left inside the leaf. This encourages more CO2
to move into the leaf by diffusion (from an area of higher
concentration to an area of lower concentration)
Lots of O2 is being made as a result of
photosynthesis. Some is used during
respiration and the rest is diffused out
of the leaf via the stomata (moving from
an area of higher concentration to an
area of lower concentration)
Leaves are designed for Gas Exchange
Leaves have stomata for diffusion
Close at night (in dark)
There are air spaces which allow
gasses to move easily through the
leaf
Large surface area
Respiratory System
Exercise
More movement= Higher breathing rate
Muscles respire and require more oxygen
Lungs and Thorax
The thorax is the top part of our body, it stops at the diaphram
Lungs= protected by ribs
Surrounded by pleural membranes
Air breathed in goes through the
trachea which splits into 2 tubes
called bronchi (one to each lung).
The bronchi splits into smaller tubes
called bronchioles which finally end
with small bags called alveoli where
gas exchange takes place
Human Gas Exchange
Alveoli
Lungs contain millions of alveoli
where gas exchange takes place
Blood coming from the rest of the body contains a high concentration of
CO2 and very little O2 so CO2 diffuses out of the blood into the alveoli to be
breathed out, while O2 diffuses out of the alveoli into the blood.
Specialised for Gas Exchange
Large surface area
Moist lining for gasses to dissolve in
Thin Walls
Good blood supply
Walls are permeable
Smoking
Smoking damages the walls of the alveoli
Tar in cigarettes damage the cilia in your lungs and
trachea which usually stop dust and germs getting
into the lungs...
Tar also irritates the bronchi encouraging
excess mucus to be produced causing smokers
cough
Carbon monoxide reduces amount of oxygen in blood so heart rate and blood pressure
increase, leading to heart disease ect..