bioenergetics Flashcards
what is the word equation for photosynthesis?
carbon dioxide + water (with light) —> glucose + oxygen
what is the symbol equation for photosynthesis?
6CO2 + 6H2O —> C6H12O6 + 6O2
what is glucose used for?
- respiration
- cellulose
- amino acids
- stored as oils/fats
- stored as starch
what are limiting factors?
An environmental factor which can restrict the rate of a process happening
what are the limiting factors of photosynthesis?
- light
- carbon dioxide concentration
- temperature
where does photosynthesis take place?
Within chloroplasts in leaf palisade cells. they contain chlorophyll, a pigment which absorbs light energy.
is photosynthesis endothermic or exothermic?
Endothermic, energy is transferred from the environment to the chloroplasts by light.
Give an example of a leaf adaptation to maximise photosynthesis:
1) broad leaves - maximise surface area
2) thin leaves - short diffusion distance
3) chlorophyll present - trap light energy
4) veins - transport water to leaves via xylem, remove photosynthesis products via phloem
5) air spaces - allow CO2 to enter and O2 to leave
What law describes the relationship between the distance of a light source from a plant and light intensity?
inverse square law
I = k / d^2
What is the process that occurs in plants and algae to produce glucose and oxygen?
Photosynthesis
How does carbon dioxide enter the leaves of plants?
By diffusion
How does water enter the roots of plants?
By osmosis
Why is photosynthesis described as an endothermic reaction?
Because energy is transferred from the surroundings to chloroplasts by light
How does temperature affect the rate of photosynthesis?
As temperature increases, the rate of photosynthesis increases until enzymes denature
How can knowledge of limiting factors help greenhouse growers?
- Maintain optimal conditions for photosynthesis
- Maximize crop yield
- Maintain profits
What is the relationship between light intensity and the rate of photosynthesis at different temperatures?
Higher temperatures and increased carbon dioxide concentration can lead to a higher maximum rate of photosynthesis
What is the inverse square law in relation to light intensity?
There is an inverse relationship between distance and light intensity - as the distance increases, light intensity decreases.
What type of reaction is respiration?
Exothermic
What are the two types of respiration?
Aerobic and anaerobic respiration
What is the main waste product of aerobic respiration?
Carbon dioxide and water
What is the equation for aerobic respiration?
Glucose + Oxygen → Carbon Dioxide + Water
What is produced during anaerobic respiration in animal cells, and what does it cause?
Lactic acid - it causes muscle fatigue (feels like cramps) and an oxygen debt
What is the difference in energy release between aerobic and anaerobic respiration?
Aerobic respiration releases more energy than anaerobic respiration.
What is fermentation in yeast cells?
It is anaerobic respiration that produces ethanol and carbon dioxide.
