Bioenergetics Flashcards
What does photosynthesis produce?
glucose and oxygen
Where does photosynthesis take place?
in chlorophyll, in chloroplasts in green plant cells
What do chlorophyll do?
absorb light
how is energy transferred to the chloroplasts from the environment?
by light
what type of reaction is photosynthesis?
endothermic, takes in energy from surroundings
What is the word equation for photosynthesis?
carbon dioxide + water —-> glucose + oxygen
What is the symbol equation for photosynthesis?
6CO2 + 6H20 —> C6H12O6 + 6O2
What 5 things do plants use photosynthesis for?
- respiration
- making cellulose
- making amino acids
- stored as oils and fats
- stored as starch
How is photosynthesis used for respiration?
transfers energy from glucose which enables the plants to convert the rest of the glucose into other substances
How is photosynthesis used for making cellulose?
glucose converted into cellulose for making strong plant walls
How is photosynthesis used for making amino acids?
glucose combined with nitrate ions to make amino acids which are then made into proteins
How is photosynthesis used for storing oils and fats?
glucose turned to lipids for storing in seeds
How is photosynthesis used for storing starch?
glucose turned to starch and stored in roots, stems and leaves for when photosynthesis doesn’t occur
What is the rate of photosynthesis effected by ?
- light intensity
- concentration of CO2
- temperature
- amount of chlorophyll
what is a limiting factor?
something stopping photosynthesis from happening any faster
How are distance and light intensity related?
as distance increases, light intensity decreases - inversely proportional
how do you measure light intensity?
1/d^2
How can you create an ideal environment for plants to grow?
using a greenhouse
What doe greenhouses help to do?
-trap suns heat and ensure temperature doesn’t become limiting
What does a paraffin heater do?
increases level of CO2 in a greenhouse
What are the disadvantages of using a greenhouse?
- costs money
What is respiration?
the process of transferring energy from glucose, which goes on in every cell.
What do all living things do?
respire
what type of reaction is respiration?
exothermic
Give three examples of how organisms use the energy from respiration?
- build larger molecules from smaller ones
- to allow muscles to contract
- in mammals and the birds it is used to keep body temperature steady in colder surroundings
What is metabolism?
the sum total of all the chemical reactions in an organism
What are chemical reactions controlled by?
enzymes
Explain an example of when larger molecules are made from smaller ones?
- small glucose molecules are joined together to make starch, glycogen and cellulose
give an example of when larger molecules are broken down to make smaller ones?
- glucose is broken down in respiration
What is aerobic respiration?
respiration using oxygen, most efficient way to transfer energy from glucose
When does aerobic respiration take place?
all the time in plants and animals
Where do most the aerobic reactions take place?
Inside the mitochondria
What is the word equation for aerobic respiration?
glucose + oxygen —> carbon dioxide + water
What is the symbol equation for aerobic respiration?
C6H12O6 + 6O2 —> 6CO2 + 6H2O
When is anaerobic respiration used?
When there is not enough oxygen, during exercise
What does anaerobic mean?
without oxygen
What is anaerobic respiration?
the incomplete breakdown of glucose, making lactic acid
What is the word equation for anaerobic respiration ?
glucose —–> lactic acid
What is the difference between aerobic and anaerobic respiration?
anaerobic does not transfer as much energy as aerobic respiration because glucose isn’t fully oxidised
What do plants and yeast cells produce?
ethanol and carbon dioxide
what is the word equation for anaerobic respiration in plants in yeast?
glucose —> ethanol + carbon dioxide
what is anaerobic respiration in plant and yeast cells called?
fermentation
How is fermentation used in industry?
bread making, - carbon dioxide makes bread rise
beer and wine making - fermentation produces alcohol
What do muscles need?
energy from respiration to contract
What increases in order to get more oxygen into your blood?
- breathing rate
- breath volume increases
- heart rate
Why is anaerobic respiration bad?
lactic acid is produced which builds up in muscles and become painful
What can long periods of excursive cause?
muscle fatigue
What is oxygen debt ?
amount of extra oxygen your body needs to react with the build up of lactic acid and remove it from cells
What stays high when there are high levels of lactic acid and CO2?
- pulse
- breathing rate
What else does the body do to cope with high levels of lactic acid?
blood in muscles transports the lactic acid to the liver. The liver then converts the lactic acid into glucose
How can you measure breathing rate?
counting breaths
How can you measure heart rate?
taking a pulse
