11.1 - Overview Of Photosynthesis Flashcards
In plants, energy from light is absorbed via
- Chlorophyll
- then it’s transferred into the chemical energy of the molecules formed during photosynthesis
- These molecules are used by the plant to produce ATP during respiration.
What is the main photosynthetic structure in eukaryotic plants + what is the organelle where photosynthesis takes place
- leaf
- chloroplast
Leaves are adapted to bring together which three raw materials of photosynthesis?
- water
- carbon dioxide
- light
Leaves are adapted to remove its products of photosynthesis, what are they?
- oxygen
- glucose
What are the 9 adaptations of the leaf for photosynthesis
- large Surface Area = absorbs as much sunlight as possible
- leaves arranged to minimise overlapping = avoids shadowing of one leaf by another
- thin = as most light is absorbed a few micrometres of the leaf + keeps diffusion distance for gases short
- transparent cuticle and epidermis = let light through to the photosynthetic mesophyll cells beneath
- long, narrow upper mesophyll cells packed with chloroplasts = collect sunlight
- numerous stomata for gaseous exchange so that all mesophyll cells are only a short diffusion pathway from one
- stomata that open and close in response to changes in light intensity
- many air spaces in the lower mesophyll layer = allows rapid diffusion in the gas phase of carbon dioxide and oxygen
- network of xylem that brings water to the leaf cells, and phloem that carries away the sugars produced during photosynthesis.
- “Sunny Leaves Thrive Through Light And Sun”
Write out the equation for photosynthesis
Because photosynthesis involves many intermediate reactions, it is known as a…..
Metabolic pathway
What is some of the energy that comes from capturing light conserved as
Chemical bonds
What are the 3 main stages to photosynthesis
- capturing of light energy
- the light-dependent reaction
- the light independent reaction
Briefly describe the 1st stage of photosynthesis
- capturing of light energy
- done by chloroplast pigments such as chlorophyll
Briefly describe the 2nd stage of photosynthesis
- the light-dependent reaction, in which some of the light energy absorbed is conserved in chemical bonds.
- During the process an electron flow is created by the effect of light on chlorophyll, causing water to split (photolysis) into protons, electrons, and oxygen.
- The products are reduced NADP, ATP, and oxygen.
Briefly describe the 3rd stage of photosynthesis
- the light-independent reaction
- the protons (hydrogen ions) are used to produce sugars and other organic molecules.
Describe the general dimensions of a chloroplast
- vary in shape and size
- but are typically disc-shaped, 2-10 micrometers long, and 1micrometer in diameter
Describe the outside of a chloroplast
Surrounded by a double membrane
Describe the inside of a chloroplast
2 main regions
- the grana (+thylakoids)
- the stroma
Describe the grana region
- The grana are stacks of up to 100 disc-like structures called thylakoids
- it’s where the light-dependent stage of photosynthesis takes place
- Within the thylakoids is the photosynthetic pigment called chlorophyll
- Some thylakoids have tubular extensions that join up with thylakoids in adjacent grana
- These are called intergranal lamellae.
Describe the stroma region
- The stroma is a fluid-filled matrix where the light-independent stage of photosynthesis takes place.
- Within the stroma are a number of other structures such as starch grains.
State in which parts of the chloroplast each of the following occur:
- the light-dependent reaction
- the light-independent reaction.
- Grana/thylakoid
- Stroma
Name the products of each of the following:
- the light-dependent reaction
- the light-independent reaction.
- Reduced NADP, ATP and oxygen
- Sugars and other organic molecules
