Physiology of Marine Primary Producers Flashcards
What do primary producers fix?
inorganic carbon and make organic compounds available to herbivores and other organisms in food chains/webs
What is the word equation for photosynthesis?
Carbon dioxide + water -> glucose + oxygen
How can primary production also occur?
chemosynthesis
What is chemosynthesis?
Oxidation of inorganic substances such as hydrogen sulfide and ammonia
Where are most photosynthetic primary productivity carried out?
Phytoplankton
What is photosynthesis
The process by which plants capture light energy from the sun and use this to from chemical bond energy in organic molecules (such as carbohydrates).
What is Thylakoids?
membranes with pigments to absorb light energy
What are Ribosomes used for?
for protein synthesis (make enzymes need for photosynthesis)
What does DNA contain?
genes for enzymes required
What are the two main stagees of photosynthesis?
Light dependent and light independent
What do light dependent reactions do?
Capture light energy from the son
Waht does light dependent reaction require
“pigments” (colored substances) which absorb light energy and start the process of photosynthesis
Where are pigments found?
in chloroplasts of eukaryotes (plankton and plants)
Give 2 examples of pigments
- Chlorophylls
- Carotenoids (ß-carotene , Fucoxanthin, Phycobilin)
What is a light independent reaction?
When CO2 is fixed into organic molecules
How are individual reactions controlled in a light independent reaction?
By enzymes
How is it possible to extrat and separate pigments?
Using chromatography
What is chromatography?
the separation of a mixture by passing it in solution through a medium in which the components move at different rates
What do chlorophylls have?
A green color
What do chlorophylls absorb?
Light in red and blue-violet part of the spectrum
Name the 2 forms of chlorophyll
Chlorophyll a and b
What do carotenoids absorb
yellow orange pigments
Where do carotenoids best absorb?
in blue-violet and green wavelengths
What are other pigments found in algae?
Fucoxanthin and phycobilins
What is fucoxanthin
a yellow brown pigment
Where is fucoxanthin found?
in brown algae (reflects brown light)
What do fucoxanthins absorb?
blue-violet light
What is phycobilin?
a red and blue pigment
Where is phycobilin found?
in red algae (reflects red light)
What do phycobilin absorb?
green, violet, and blue light
How does light intensity change with depth?
As we go deeper, the intensity of sunlight decreases, as the light is absorbed by the water and the bodies that are to be found inside it.
What radiation decreases at a the fastest rate with increasing depths?
red radiations
List the order of radiations that decrease as depth increases
red, orangrage, yellow, green, blue, indigo (roygbi)
What do chloroplast pigments absorb?
Certain wavelengths of light most strongly
Apart from CO2 what mineral ions are needed for phytoplankton growth?
Calcium, magnesium, nitrogen, phosphorus
What can the availablility of nitrogent and phosphorus do
limit growth
What are the factors that affect the rate of photosynthesis?
- Light intensity
- Light wavelength
- Concentration of carbon dioxide
- Temperature
What happens as light intensity increases?
so does the rate of photosynthesis until another factor becomes limiting
What can happen if the light intensity is too high?
the rate of photosynthesis can decrease, due to damage to the photosynthetic structures
What is the reult of light intensity decreases as depth increases?
Upper regions of the ocean have the highest level of photosynthetic productivity
When does the light compensation point occur?
at a light intensity where the volume of CO2 produced in respiration is the same as the volume of CO2 used in photosynthesis
What happens as light intensity increases further?
the rate of photosynthesis exceeds the rate of respiration and there is a net uptake of CO2
What is the absorbtion spectrum?
a graph showing the relationship between absorbance and wavelength for a pigment
What is the action spectrum?
a graph showing the relationship between the rate of photosynthesis and the wavelength of light
What does a wide range of pigments being present in different species of phytoplankton enable?
enables them to utilize a wide range of wavelengths of light for photosynthesis
What happens to the rate of photosynthesis as temperature increases
it increases until it reaches an optimum as the enzyms being to denature
What is an algal bloom
where there is a high concentration of nutrients, plankton may grow rapidly giving rise to a ‘bloom’
What may a red tide contain
toxic species of dinoflagellates
List 3 primary producers
–Phytoplankton
- Larger algae such as Sargassum
- Flowering plants such as the sea grasses
What primary producesrs are found in shallow coastal waters?
- Sea grasses (Thalassea and Zostera)
- Zooxanthellae (in coral)
- Kelp forests
What is primary producers is found in the intertidal region?
Green, red and brown algae
What is primary producers is found in the open ocean?
- Phytoplankton like Diatoms, Dinoflagellates, and Cyanobacteria
- Floating large algae (Sargassum)
How do sea grase inporve the water quality?
by absorbing nutrients and attracting particles to their blades
What does sea grass help reduce?
water current speed and increase sedimentation (grows in shallow coastal waters with a sandy or muddy substrate )
reduce coastal erosion as roots and rhizomes stabilise the substrate
What is kelp?
A brown algae
Where do kelp live?
in cool, nutrient rich and relatively shallow waters (up to 40 m deep) close to the shore
What algae are found on rocky shores?
green and red
What is the photic zone?
surface layer of the ocean in which there is enough light for Photosynthesis
What accessory pigments do species of phytoplankton in deeper parts of the photic zone contain?
Xanthophylls and Phycobilins
What do Phycobilins absorb?
light in the middle part of the visible spectrum (B,Y,G)
Where do green live ?
where red light is more abundant
Where do brown algae live?
where yellow light is more abundant
What do brown algae use?
Fucoxanthin
What do red algae have?
Red pigments called phycobilins
Why do red algae have phycobilins?
To make absorption of green light possible
What are diatoms made of?
silica and their yellow-brown chloroplasts
What do dinoflagellates have
2 flagella
What is Cyanobacteria?
A blue green algae
What do Cyanobacteria not have
A chloroplast
