Bioenergetics Flashcards
What is photosynthesis?
An endothermic reaction where light energy is transferred by chloroplasts to produce glucose
What is the word equation for photosynthesis?
Carbon dioxide + water —> glucose + oxygen
What is the symbol equation for photosynthesis?
CO2 + H2O —> C6H12O6 + O2
Where in the plant does photosynthesis take place?
Inside the chloroplast in plant cells
Do all plant cells have chloroplasts?
No, only the ones that receive light
Which plant cells have the most chloroplasts?
The cells that receive the most light, the palisade mesophyll cells in leaves
What factors affect the rate of photosynthesis?
Light intensity,carbon dioxide concentration,temperature,amount of chlorophyll
Why does temperature affect photosynthesis?
Photosynthesis uses enzymes and if the enzyme gets warmer, photosynthesis happens at a faster rate but if enzymes get too hot, they will denature and photosynthesis will stop
What other organisms photosynthesise?
Algae as well as some bacteria (if there is a chloroplast it will absorb light energy and photosynthesise)
What is the inverse square law?
The light energy reaching a certain point is equal to the in verse square of the distance to that point. We can turn distance into light intensity by using 1/d2
Why does anyone care about rate of photosynthesis?
Anyone producing food crops will want to maximise profit, adding lighting, carbon dioxide or heat into a greenhouse will give faster growth but may cost more
What is the glucose produced in photosynthesis used for?
Respiration by all living cells. Also some is converted into starch,fats/oils,cellulose and amino acids
Why do plants store glucose as starch?
Starch is insoluble so it doesn’t affect osmosis. Also it is more compact so easier to store large amounts, starch is also used by cells as a source of glucose for respiration when it’s dark
Why do plants convert some glucose into oils?
Seeds have oils stored in them as the energy supply for the new plant to start to grow
Why do plants convert some glucose to cellulose?
Cell walls are made of cellulose. It is strong and helps support the plant as all plant cells have cell walls
Why do plants convert some glucose into amino acids?
Amino acids are the building blocks of protein (for growth and repair). Plants need amino acids for protein synthesis (plants are responsible for producing many of the amino acids we rely on)
What else do plants need to turn glucose into amino acids?
Glucose contains elements CHO. Amino acids contain CHON and plants need to get the nitrate ions from the soil to make amino acids
What is respiration?
An exothermic reaction where energy is released from glucose molecules. It happens continuously in all living cells.
Why do living cells need to respire?
Living cells need an energy supply for all the processes they carry out, without it the cells would die
What are the two types of respiration?
Aerobic (with oxygen) and anaerobic (without oxygen)
What is the word equation for aerobic respiration?
Glucose + oxygen —> carbon dioxide + water (and energy is transferred but its not a chemical)
What is the word equation for anaerobic respiration?
Glucose —> lactic acid (less energy transferred)
Is all anaerobic respiration the same?
No, the equation glucose —> lactic acid is for muscles but in plants and yeast its glucose —> ethanol + carbon dioxide
What is the anaerobic respiration equation in plants/ yeast?
Glucose —> ethanol + carbon dioxide
