C1 Flashcards
What is photosynthesis and where does it occur?
- Proccess that converts solar energy into chemical energy
- Occurs in the lead of a plant
What is the formula for photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
Light
How does light travel?
Travels in waves called photons (small units of energy)
Light
What is the difference between short wavelength and long wavelengths
- Short wavelengths have high energy (UV rays, x-rays, gamma rays)
- Long wavelengths have low energy (infraredm microwaves, radiowaves)
What is visible light and whats its use in plants?
- Visible light is white light which is a mixture of all light
- plants use it for photosynthesis
Describe chlorphyll and its use
- Green colored pigment
- Found in plants, algae, protists, and cyanobacteria
- Absorbs photons and begins photosynthesis
What is the main pigment of a choroplast?
Chlorphyll a (blue-green): Most importan pigment to absorb energy
What are the accesory pigmets and what do they do?
- Chlorophyll b (Yellow-green)
- Carotenoid
- Take lightand convert it into energy for plant
What do accesory pigments do?
They absorb other photon wavelenghts and pass the energy to chlorophyll a
What is a spectrophotometer?
An instrument that can determine the absorption spectrum of pigments: shows which pigment absorbs which wavelenght of color
What is chromtagraphy?
Technique used to seperate pigments
* Pigmensts dissolved in fluid
* Fluid passes through materials
* pigments move at different speeds (distance)
Whats the formula for Chromatagrpahy?
RF value= Distance pigment travels/distance solvents travels
Chloroplast structure
What is a chloroplast?
Clusters of chlorophyll are found in plant organelles are called chloroplasts
Chloroplast structure
What is a Stroma?
Gel-like enzyme-rich substance filling the chloroplast
Chloroplast structure
What is a thylakoid?
A system of membran bound sacs that stack on top of each other. each have lumen which is a fluid-filled space inside
Chloroplast structure
What is a granum?
Stacks of thylakoid discs, one chlorplast may have 60 grana each with 30-50 thylakoids
Chloroplast structuer
Lamella
Unstacked thylakoids connecting adjacent grana
What is the palisade tissue cell?
- Long, narrow cells packed chloroplast
- Lie under the upper surfae an is where most photosynthesis happens
What is the Vascular tissue cell
- Bundled arrangement of tubes that transport fluids
- Xylem carry water and minerals
- Phloem carry sugars
what is the Spongy tissue cell?
- Round and more loosely packed with air spaces
- have chloroplass and helps ells exchange gas and water
What is a Stomata?
- Small openings in outer layer
- Allows carbon dioxide into leaf and oxygen out
- Water also diffuses
What is the use of glucose?
- Transports molecules (blood sugar)
- Medium-term energy storage
Describe ATP
- Is a high energy molecule used by all living cells
- Provids immediate source of energy for cellular processes
- formed by addition of ADP and P
Describe NADPH
- During photosynthesis NADP+ acquires 1 H atom and 2 E- to form NADPh
- NADPH is an electron donor so it becomes NADP+ again
- Inolved in energy transfers
Stage one of photosynthesis
Photosystems
- Clusters of photsynthetic pigments embedded in the thylakoid membrane
- responsible for capturing light
Oxidation
Compounds lose an electron making it oxidized
**
Reduction
Compounds gain electrons making it reduced
Stage 2 of photosynthesis
Explain the first step of ETC (electron transport chain)
Electrons from photsystem II are transferred along ETC and across the thylakoid membrane to the inner surface
Stage 2 of photosynthesis
Explain the second step of ETC
Some of the energy is used to pull hydrogen ions across the membran which results in positive charge build up in the lumen
Stage 2 of photosynthesis
Explain the third step of ETC
Electrons that lost lots of orginal energy are transferred to chlorphyll molecules in psl where they absorb energy again
Stage 2 of photosynthesis
What is the fourth step in ETC
High-energy electrons from photosystem I are trasnferred into NADP+ to from NADPH
Stage 2 of photosynthesis
What are ATP synthase complexes
Protein complex embedded in thylakoid membrane that allows Hydrogen ions to escape form lumen and use resulting energy to make ATP
Calvin Cycle
Describe the calvin cycle
- Does not require energy from photons
- Occurs in stroma
- Main mechanism is cabron fixation: froms high energy organic molecules from CO2
- Utilizes ATP and high energy electron carried by NADPH to make G3p
Calvin Cycle
What is G3P and where does it get its needed elements
- It is a sugar used to make glucose
- It gets carbon and oxygen from CO2
- It gets ATP and NADPH from light dependet reactions
Calvin Cycle
How much ATP and NADPH is consumed when 1 CO2 enters
- 3 ATP
- 2 NADPH
Calvin Cycle
How much ATP and NADPH produce 1 glucose
- 18 ATP
- 12 NADPH
Calvin Cycle
How much water is consumed for each glucose created
6 water
Calvin Cycle
Describe Carbon Fixation
CO2 molecules combin with RuBP which splits into 2-3 carbon compounds (3-PGA)
Calvin Cycle
describe reduction
ATP and NADPH used to convert 3-PGA into G3P
Calvin Cycle
describe regeneration
Some G3P makes gljcose, soe are recycled to generate RuBP (requires ATP)
Simplify three stage
- Capturing solar energy -> electrons
- Using solar energy -> make ATP, transfer hiigh energy electrons to NADP+; yeilds NADPH which is then used as a high energy electron carrier molecule
- Using energy stored in ATP and high energy electrons carried by NADPH to energy rich organic molecules such as gluecose from CO2
Simplified Light dependent reactions
Step 1: Photo-excitation
- Photon from the sun strikes a molecule of chlorophyll inside of PSII (wavelength of 680)
- That electron absorbs the energy from the photon and gets excited (low energy to high energy due to the photon)
- It leaves Photosystem II to travel down the ETC towards PSI
Simplified Light dependent reactions
Step 2 : ETC (PSII → PSI)
- Electrons move through the proteins in the ETC
- As it moves through the ETC, the electron releases energy (decreased potential energy)
- The chain uses energy released from the electron to bring hydrogen ions into thylakoid
- Photosystem II transfers the free electron to a series of proteins that are found inside the thylakoid membrane
Simplified Light dependent reactions
Step 3: Photolysis
- Occurs in thylakoid
- Water is split into hydrogen, oxygen, and a electron
- Electrons removed from photostem is replaced by water molecules
Simplified Light dependent reactions
What is photolysis
Water molecules split by light
Simplified Light dependent reactions
Step 4: chemiosmosis
- Hydrogen is pumped into thylakoid lumen and the resulting energy helps generate ATP through a REDOX reaction
- ATP Synthase Complexes: protein complex embedded in thylakoid membrane that allows H+ ions to escape from lumen and uses the resulting energy to generate ATP
Simplified Light dependent reactions
Step 5: Reduction ADP→ ATP
Once the hydrogen ions pass through ATP synthase a reduction reaction occurs
Simplified Light dependent reactions
Step 6: ETC (PSI→stroma)
- Remember: this is occurring within the thylakoid membrane
- Electron absorbs the energy from the photons (photoexcitation)
- Once it absorbs a lot of energy, it leaves PSI to head towards the stroma
Simplified Light dependent reactions
Step 7: Reduction NADP+ → NADPH
- NADP+ is reduced
- NADPH is oxidized
- NADPH has reducing power because it can donate an electron
