Photosynthesis - Chapter 10 (Exam 3 Bio)
Terms in this set (119)
Captures light energy that has traveled from the sun and converts it to chemical energy that is stored in sugar and other organic molecules
Located in unicellular and multicellular eukaryote
"self-feeders"; Produce their organic molecules from CO2 and other inorganic raw materials obtained from the environment
Plants; use light as a source of energy to synthesize organic substances
The first living photosynthetic organisms.
Prokaryotes photosynthetic organisms
What is the basic formula of photosynthesis?
6CO2 + 12H2O + light -----> C6H12O6 + 6O2+ 6H2O (the oxygen is a byproduct)
What is the basic formula for glucose?
A source of energy or in structural ways in living organisms.
What can be considered a hydrocarbon?
Glucose. But it's a carbohydrate more specifically. 6 carbons, 12 oxygens and 6 hydrogens. This side group gives it a particular function or a different type of sugar.
What is a saccharide?
Individual unit (glucose)
Dimer of two monomers in sucrose
Lots of different types of sugars. Long term energy storage form and structural forms.
What is the source of sugars?
What is starch?
What is in plant cell walls?
Polysaccharides called cellulose
What makes up cellulose?
The carbon from the air
What are plants?
Multicellular eukaryotes that do photosynthesis.
What can plants do?
Fix CO2 from the air, make glucose, connect the monomers together to make cellulose that wraps around cell to give the cell rigid structure and shape.
Which parts of flowers take CO2 an water in presence of sunlight to make glucose?
The green stuff, which means it has chlorophyll and those are associated with chloroplasts
Where is chloroplast located?
In the leaves
What hangs off of the carbon?
Side groups or functional groups, and depending on what they are, you can different types of sugars - maltose and sucrose, for example.
What happens in the chemical equation?
CO2 and water are combined in the presence of energy, in an endothermic reaction to produce or synthesize glucose.
Where does the oxygen come from?
What type of biological compound is glucose?
What did Gregor Mendel teach us about plants and photosynthesis?
The union of the egg and sperm is the first diploid cell of the plant. It goes through mitosis to make plant embryo, which is later encased in a seed. The seed is planted and wakes up in the ground, root and shoot system develops, and the plant starts doing photosynthesis but it must have water, CO2 and sunlight to make glucose.
What happens with the cell according to Mendel?
The first diploid cell is a zygote. There's a single nucleus with two copies of every chromosome. That DNA in that cell is replicated in the cell cycle to make two cells. The cell cycle ends in mitosis. Do the cells look the same? No they became different, which is differentiation: One is called the terminal cell and the other is the basal cell. They are different, but they have same DNA.
The first cell replicated to make daughter cells and the daughter cells each turned on genes on and off differently. So they look different. That's differentiation. Even though the DNA is the same from the parental cell , they turned on the genes differently.
One is called the terminal cell and the other is the basal cell. They are different, but they have same DNA. The first cell replicated to make daughter cells and the daughter cells each turned on genes on and off differently. So they look different. Even though the DNA is the same from the parental cell , they turned on the genes differently
What happens in the first division?
Up and down for the plant sets up what will be roots and what will be stems.
Single diploid zygote divided into two to basal and terminal cell (differentiation). There's different tissue types in the leaf .There's vascular tissue, mesophyll cells, and epidermis.
What does the beginning plant have?
The beginning plant has two cotyledons. Those seed leaves consist of millions of cells, that contain chloroplasts, loaded with pigments. The plant in those organs produce chlorophyll so the plant can use sunlight.
Are the cells in leafs identical?
Not all identical. They have same genetic information but turned on genes in different ways to get an organ with different tissue types of, consisting of specific types of cell
What do plants use to make sugar?
CO2 in the air to make sugar. It's not easy to do and requires dozens of intermediate steps catalyzed by enzymes
Converts light energy to the chemical energy of food and stored energy (occurs in the leaves)
What organisms perform photosynthesis?
Bacteria, plants and protists
What is the absence of oxygen?
What is the presence of oxygen or the use of oxygen?
What is anaerobic respiration?
What organisms perform photosynthesis
Where are chloroplasts found
In the cells of the Mesophyll
The tissue in the interior of the leaf
What does carbon dioxide do in leaves? What exits?
Carbon dioxide enters the leafs and oxygen exits
Organs in the plant that consist of dermal tissue, vascular tissue (xylem and phloem ) and ground tissue (but not in the ground)
Where are chloroplasts found?
These are organelles that we find inside a cell. Usually dozens of chloroplasts in the cell. It has inner membrane and outer membrane.
How are plants different from us?
Metabolism except in the leaves.
What do all the cells in leaves have?
Single nucleus with two copies of every chromosome but the cells have differentiated to have different roles in the plant
Energy that is used from chemicals such as methane or hydrogen gas to synthesize sugars
Water and CO2 supply energy to get glucose and the byproduct oxygen.
What happens if we turn the lights off (the plant gets no sunlight, nighttime)
The CO2 levels will go up around me and oxygen would go down
What happens if we turn on the lights
The chlorophyll start harvesting that light to convert to chemical energy and store in glucose. Byproduct is oxygen
What does the structure of the membrane allow the cell to do?
To take sunlight and make it into sugar
The upper epidermis
Give waxy layer to prevent water loss. The cells produce waxy substance and it's pushed onto the surface of the leaf to prevent water loss.
What is the waxy substance that is produced called?
Cuticle (made by epidermal cells)
What do living cells in the upper and lower epidermis do?
Turn on different genes to make proteins to make waxy substances for the outer surface of the leaf.
The lower epidermis
They turn on different genes as they were grwing up, to make a hole that is open or closed on the bottom of the leaf
What happens when stomata is open?
Allows for CO2 to enter the leaf
What can open the stomata?
So if the inside the upper and lower portion of the leaf is 100% humidity, and the outside is drier... this opens the stomata
What happens when stomata closes?
CO2 can't enter the leaf
What happens when a leaf is too dry?
If it is hot and dry outside and the stomata is open, water will leave. If enough leaves and the plant becomes too dry it will actively close to prevent water loss. When stomata closes, CO2 can't enter the leaf. (Doesn't loose water, looses CO2, and glucose can't be made)
How does CO2 and O2 pass in and out the leaf?
Stomata (pair of guard cells)
Singular of stomata
What does stomata have?
Two guard cells
What happens to water in leaves
Absorbed by the roots and is delivered to leaves and veins
What does stomata do
1. (Mouths) Open and closes due to carbon dioxide concentration and humidity (Microscopic openings in the lower epidermis of leaves)
2. Opens and closes in response to the internal pressure of two sausage shaped guard cells that surround it.
What determines the opening or closing of the stomata?
Water; when there's not enough water in the plant, they're shut, and they're open to let CO2 in
What do leaves use veins for
Export sugar to roots and other non photosynthetic parts of the plant
How do plants balance CO2 and water?
If CO2 is used up by photosynthesis, the plant wants to open up the guard cells forming mouths called stoma, to let CO2 in.
The plant has to deal with water moving into the guard cells to open them, and water moving out to close them.
So in dry conditions inside the leaf, the plant pumps water out of guard cells and the pores will close. Plant is using up its CO2 in photosynthesis and now there's not enough CO2, so a signal is sent to the guard cells to open the guard cells up to let in CO2.
The middle of the membrane is?
Hydrophobic (therefore water needs to help it)
What helps water cross the membrane?
A protein called aquaporin (hole in a protein)
What do aquaporins do?
These proteins make holes in the membrane that are specific to water (high concentration)
Moving from high concentration to low concentration
Water can move through membranes with help
Water can move across the membrane without help
What are factors that control stomata opening and closing?
The CO2 concentration
So at a low CO2 concentration, the water moves into the guard cells, so the stomata open, so CO2 flows in, because it goes from high concentration to low concentration
What is another factor that controls stomata opening and closing?
The relative humidity between the inside and outside of the plant
If it's hot and dry, especially if there's wind moving across surface of leaf, the water loss is higher, so water moves up from the roots to the shoots of plant. Cells inside the leaf sense the dryness, so water moves out of guard cells, they shut to prevent further water loss.
When do the plants let CO2 in?
At dawn, the plants open the guard cells to let CO2 in, so when the first sunlight comes out, and it also tends to be more humid, plant does more photosynthesis.
What happens at about noon or 1 or 2 in the afternoon?
The air becomes drier, plant will sense that, and they will close the pores to prevent further water loss. Depends on relative humidity.
Protein in membrane can use energy to grab something outside the membrane at low concentration and forces it across to higher concentration
What kind of passport does membranes use?
Passive transport; movement down concentration gradient; no Energy required
Receptor, Recognition, Transport
Trigger cellular response when
specific molecules attach
ID tags and attachment sites
Diffusion of water
What does the plant actively transport inside of the cell?
Ions into the guard cell, water follows it (guard cells opens, stomata opens)
What does the plant use ATP for?
To actively transport potassium and chloride inside and also to the outside. This process is controlled by the plant.
It has three membrane system: outer membrane, inner membrane and thylakoid. All are barriers to movement of stuff across the membrane.
List all of the membranes
inner membrane and outer membrane, and then the thylakoid membrane (inner inner membrane if you like)
The solution inside the inner membrane but outside of thylakoid membrane
Stacks of thylakoids; light harvesting capabilities
These are the solar panels of the plant. They convert solar energy into stored chemical energy, also use the energy in photons to synthesize ATP from ADP and also synthesize NADPH
What does the light independent reactions use from the light dependent reactions?
The light independent reactions, the synthesis part, uses energy from the light dependent reactions (ATP and NADPH) to synthesize a 6-carbon compound called glucose, Where does that occur? In the solution inside the chloroplasts, not inside the thylakoids
Where does this reaction with the li
Two parts of photosynthesis
Light dependent reactions, and the synthesis part called the light independent reactions
Where does the light dependent reactions occur?
Where does the light independent reactions occur?
Light Dependent Reactions
Convert stored solar energy as potential energy
Energy of photons used to synthesize ATP and
Light Independent Reactions
Energy stored in ATP, NADPH used to synthesize
C6H12O6=glucose, occurs in the solution in the chloroplast "synthesis"—in Stroma
Where do the photosystems occur
Occurs in the thylakoid membrane. o PS II--> lots of ATP
PSI --> NADPH
Passed on to the stroma and takes CO2 from the air and converts it into a 6 carbon carbohydrate called Glucose.
How is the structure of a membrane related to its function?
1. Selectively isolates inside of the cell(organelle)
2. Regulates exchange of substances in and out of
the cell (organelles).
3. Communication with other cells
Glycerol with 3 fatty acids
One phosphide group and 2 fatty acids
What does the light dependent reactions require?
Photons from sun, and using water, producing ATP, and changes to charged form... NAD+ charged form called NADPH
What is the stored energy (ATP and NAPH) used for?
It's used to take CO2 and water to produce glucose. That's the factory or synthesis part of photosynthesis.
List endergonic reactions
CO2 plus water to make glucose, Get energy from ATP. This is a coupled reaction between ADP and ATP
What happens when the suns energy is converted?
The sun's energy gets converted to ATP and NADPH, and that's source of energy to make the glucose.
In the spectrum of radiation (the light that we see) 400-700 nm
Why is chlorophyll green?
Because all the colors (of the rainbow) in light are absorbed except the green, which is reflected. Absorbs violet, blue and red light and reflects green
Pigments we don't see. They're in low concentration which means these can accept the different regions of the spectrum than chlorophyll can to increase the effectiveness of absorbing the sunlight
They absorb green and yellow and reflect blue and purple
Photosynthetic Accessory Pigments
Chlorophyll, Phycocyanins, and Carotenoids
Accessory pigment, Absorbs blue and green light, Reflects yellow orange, and red
What are the two main locations that photosynthesis occurs in?
The photo part = The thylakoid membrane
The synthesis part = The stroma of the chloroplasts.
How many photosystems are in light dependent reactions?
2. Photosystems I and II
Which occurs first out of the photosystems?
Photosystems II but Photosystem I was discovered first (the energy is passed to photosystem I for the light independent reactions)
What is the purpose of the photosystems?
We start with photosystem II then photosystem I to produce ATP and NADPH (Passes energized electrons (e- ) to photosystem I. This charges NADP to become NADPH)
Builds H+, and that's a proton, splits H2O, delivers electrons to Photosystem I
When the sunlight hits the photosystem II, it leads to build up of protons on one side - a lot of potential energy
What does CO2 and water form in photosystem II
Remember the CO2 and water forms glucose and oxygen in photosynthesis. So here's where the water comes in