6. Photosynthesis Flashcards
What is the chemical formula for photosynthesis?
6 CO2 (g) + 6 H2O(I) + light energy 🡪 C6H12O6 (aq) + 6 O2 (g)
Whats the goal of photosynthesis
To synthesize glucose
Give an overview of the steps of photosynthesis
- Capture light energy
- Make ATP and NADPH
- Use ATP and NADPH to make sugar
Is photosynthesis anabolic or catabolic
Anabolic - small molecules combined
Is photosyntheis endergonic or exergonic
Endergonic - stores energy
What are the two stages of photsynthesis
- Light dependent reactions
- Light independent (dark) reactions
Are plants autotrophs or heterotrophs
Autotrophs - produce their own food (glucose)
Where does photosyntehsis occur
Photosynthesis mainly occurs in the leaves
- Stoma - pores
- Mesophyll cells
Explain the use and location of the stomata
- Pores in a plants cuticle through which water vapor and gasses (CO2 and O2) are exchanged between the plant and the atmosphere
- Found on the underside of the leaf
What is the structure of chloroplast
Double membrane structure
- Outer membrane
- Inner membrane
Explain the components of chlorplasts
Thylakoid: a membrane bound flattened sac that looks like a poker chip
Granum: a stack of thylakoids (looks like a stack of poker chips)
Stroma: fluid surrounding the thylakoids
Thylakoid space: the space inside the thylakoid
What is light
Light is a form of electromagnetic radiation that travels in waves
What are the wavelengths of visable light
Visible light from the sun is composed of wavelengths of 750nm to 380nm (ROYGBIV)
- Red had the largest wavelengths
- Violent has the smallest
What are the largest and smallest wavelengths called
Gamma rays are the smallest wavelengths
- High energy and high frequency
Radio Waves are the largest wavelengths
- Low energy and low frequency
What are the three things that can happen to light
- Absorption
- Transmission
- Reflection
What is pigment
Pigment: a compound that absorbs certain wavelengths of visible light while reflecting others
What colours do plants absorb
Plants absorb light (energy) of ALL COLOURS coming from the sun EXCEPT GREEN
- We see plants as green because this the only color REFLECTED to our eyes
What colours do plants absorb
Plants absorb light (energy) of ALL COLOURS coming from the sun EXCEPT GREEN
- We see plants as green because this the only color REFLECTED to our eyes
What pigrment do chloroplasts contain
Chloroplasts contain two types of pigment chlorophyll: a & b
Which light does chlorophyll not absorb
Chlorophyll DOES NOT absorb green light
What is the absorption spectrum
A graph that shows the amount of light in different wavelengths a compound can absorb
What are the tree accessory pigments and their functions
- Carotenoids - Responsible for yellow-orange coloured leaves in fall. Precursor of vitamin A, helpful for low vision
- Xanthophylls - Responsible for yellow-coloured leaves in fall
- Anthocyanins - Responsible for red-coloured leaves in fall
What causes leaves to change colour in fall
The fall causes cooler temperatures meaning plants begin to break down chlorophyll colours and other pigments become viable
What is Photosynthetically Active Radiation (PAR)
Light is absorbed from the entire visible spectrum
when all pigments are combined. Amount of light avalaible for photosynthesis
