B4 Photosynthesis and Limiting Factors Flashcards
Equation of photosynthesis
Carbon Dioxide + Water -> Glucose + Oxygen
Chemical equation of photosynthesis
6CO2 + 6H2O -> C6H12O6 + 6o2
What do plants use glucose for?
Respiration (into other useful sustances) Making cellulose Making Amino Acids Stored as oils or fats (for seeds) Stored as starch
What is the rate of a reaction controlled by?
Limiting Factors
What are the limiting factors of photosynthesis?
Light
CO2
Temperature
(Chlorophyll)
In Photosynthesis more light means?
Faster rate of photosynthesis, over a certain point that just plateaus
In Photosynthesis more CO2 means?
Faster rate of photosynthesis, over a certain point that just plateaus
In Photosynthesis more temperature means?
Faster rate of photosynthesis, however over a certain point the enzymes are denatured and this causes a sudden fall in the rate.
In Photosynthesis more chlorophyll means?
The rate of photosynthesis is much faster
At which temperature do the enzymes in plants (for photosynthesis) generally get denatured?
Around 45°
What practical do we do to test rate of photosynthesis?
Canadian pondweed practical
What happens in the Canadian pondweed practical?
Pondweed and water are put in a tube with different limiting factors (ie: with or without a light at different distances/ intensities from the weed). Someone then calculates, either by eye or with a syringe, how much oxygen is released by the weed.
In the canadian ponweed practical what is the relation between distance from the light and light intensity?
They are inversely propotional
What is the inverse square law if light intensity is inversely proportional to distance?
light intensity ∝ 1/(d)^2
Advantages to a greenhouse
Very hot Can have artificial light Control over conditions (such as CO2) Easy to remove pests and diseases Fertilisers and minerarals are easy to add Grow faster
Disadvantages to a greenhouse
Can get too hot
VERY EXPENSIVE
Need to add minerals which are not present
Need to calculate the amount of resources needed perfectly
Define Respiration
Respiration is the process of TRANSFERING ENERGY from GLUCOSE, which goes into EVERY cell
What type of reaction is respiration?
Exothermic
What is energy from respiration used for?
Breaking down large molecules Contracting muscles (in animals) Maintaining body temperature (in mammals and birds)
Define Metabolism
The sum of all the reactions that happen in a cell or body
Define aerobic respiration
Respiration in the presence of oxygen
Write the chemical equation for aerobic respiration
C6H12O6 + 6O2 -> 6CO2 + 6H2O
Write the word equation for aerobic respiration
Glucose + Oxygen -> Carbon Dioxide + Water
Define anaerobic respiration
Respiration in the absence of oxygen
Write the chemical equation for anaerobic respiration (in animals)
C6H12O6 -> 2C3H6O3
Write the word equation for anaerobic respiration (in animals)
Glucose -> Lactic Acid
Which type of respiration is more effective?
Aerobic respiration because unlike anaerobic resperation, it is fully oxidising
Write the word equation for anaerobic respiration (in yeast and plants)
Glucose -> Ethanol + Carbon Dioxide
Write the chemical equation for anaerobic respiration (in yeast and plants)
C6H12O6 -> 2C2H5OH + CO2
What is anaerobic respiration called in yeast?
Fermentation
What is Oxygen debt?
After anaerobic respiration you need extra oxygen that will react with the lactic acid to get rid of it
Where in a plant does photosynthesis take place?
Primarily the leaves - in chloroplasts
Define Endothermic reaction
(Cold to touch)
More energy is absorbed than released
What type of reaction is photosynthesis?
Endothermic
What is produced when glucose molecules combine with nitrate ions?
Amino Acids
Why do plants store some glucose in starch?
So that they have stores for when they need them
What effect would a low carbon dioxide concentration have on photosynthesis?
The reaction will not have enough carbon dioxide and it will be used up quite quickly. The reaction will then stop.
What effect would temperatures above 45 have on photosynthesis?
The temperature would be too high and would make the rate of photosynthesis plummet.
How do we lower the temperature in a greenhouse?
Ventilation
Creating Shades
How do we increase carbon dioxide levels in a greenhouse?
Burning natural gas
Define Exothermic reaction
The reaction releases more energy than it has absorbed
What is respiration?
Respiration is the process of transferring energy from glucose, which goes in every cell
What type of reaction is respiration?
Exothermic
Which organisms respire?
All organisms
What do organisms do with the energy they get from respiration?
Build up larger molecules from smaller ones
(In animals) it’s used to allow muscles to contract
(In mammals and birds) it is used to maintain body temperature in changing surroundings
What controls the chemical reactions in the body?
Enzymes
How are starch, glycogen and cellulose made in the body?
Lots of small glucose molecules are joined together
How are lipid molecules made in the body?
One molecule of glycerol and three fatty acids
How are amino acids made in the body?
Glucose is combined with nitrate ions
How is urea made in the body?
Excess protein is broken down
How is glucose used in the body?
Broken down in respiration
Define Metabolism
The sum of the total reactions that happen in a cell or the body is called its metabolism
Define aerobic respiration?
Respiration using oxygen
What are the advantages to aerobic respiration?
Most efficient form of respiration
Where does respiration occur in cells?
Mitochondria
Symbol equation for respiration?
C6H12O6 +6O2 -> 6CO2 + 6H2O
Word equation for respiration?
Glucose + Oxygen -> Carbon Dioxide + Water
Word equation for anaerobic respiration in organisms?
Glucose -> Lactic Acid
What is anaerobic respiration?
The incomplete breaking down of glucose, making lactic acid
In the absence of oxygen
When is anaerobic respiration used?
In emergencies, when there is not enough oxygen
What reaction makes ethanol?
Anaerobic respiration in plants and yeast
What is the equation for anaerobic respiration in plants and yeast?
Glucose -> Ethanol + Carbon Dioxide
What is the fermentation of yeast useful for?
Bread
Alcoholic Drinks
What makes bread rise?
Carbon Dioxide in anaerobic respiration
Why do we breathe heavier in excercise?
We need to respire more and therefore need more oxygen
We also need to get rid of CO2 and lactic acid
What is muscle fatigue?
When the muscle gets tired and then stop contracting efficiently
Describe Oxygen Debt
Oxygen needed after sport when there has been anaerobic respiration
What is oxygen debt needed for?
To react with the build up of lactic acid and remove it from cells to form CO2 and Water
What happens to lactic acid in the liver?
It is converted back to glucose