Ch17- Energy for biological processes Flashcards
What occurs in photosynthesis in basic terms:
What minerals are dissolved in soil?
- N, P, K
- Mg in chlorophyll
- Fe for Cytochromes
Why can’t ATP be used as energy storage and why is ATP suitable source of energy for cells?
Label and explain the function of each organelle of a chloroplast:
What is NAD and NADP? Which one is present in Respiration or Photosynthesis?
Name and explain some adaptations of Chloroplasts:
What is stroma fluid and what is its function?
- Fluid-filled matrix
- Site of light independent stage, LIS, in photosynthesis
- Contains starch grains, oil droplets, small ribosomes (builds chloroplasts proteins), enzymes, DNA
What are photosynthetic pigments?
Photosynthetic pigments are substances that can absorb certain wavelengths of light + reflect others.
They appear the colour of wavelengths they reflect
Different pigments act together to capture maximum amount of light.
What are the 2 categories of light absorbing pigments?
What observations and conclusios can we draw from Englemann’s experiment?
- Aerotactic bacteria (ATB) sense and move towards high conc O2
- At 450nm (blue) the most ATB are present (peak @ 450), therefore must be high conc O2
- At 680nm (red) another group of ATB peak, therefore high conc O2
- The higher the conc O2 suggests greater rate of photosynthesis
- So plants absorb blue @ 450nm, red @ 680nm wavelengths best for photosynthesis
- At 500-600nm least light absorbed by chloroplasts, green/yellow, not used much in photosynthesis.
What are the different photosynthetic pigments, their colour, the peak absorption wavelength (nm), and their function in photosynthesis?
Action and Absorption spectra: identify the different photosynthetic pigments:
What is the difference between an action and an absorption spectra?
- Action spectrum: a graph of rate of photosynthesis at different wavelengths
- Absorption spectrum: a graph of absorbance of different wavelengths of light by a pigment.
Electron transfer chain, photons, p/s pigments, antennae complex
Describe how the photosystem works:
What are the two reaction centres?
What are the two stages of Photosynthesis?
What is the role of water in photosynthesis?
What are the two different types of phosphorylation?
What are the steps in Non-cyclic photophosphorylation?
- Non-cyclic photophosphorylation (NCP) takes places at thylakoid membrane
- A photon of light strikes PSII (p680) + energy is harvested into primary pigment reaction centre.
- This excites a pair of e- to higher orbital, escaping chlorophyll
- The pair of e- are captured by electron carriers (protein) than pass along e- in electron transfer chain (ETC)
- At each stage, a bit of energy is released
- The e- lost in PSII are replaced by photolysis h+ remains in thylakoid space + O2 is released as by-product through stomata and used for respiration
- The energy released form ETC used to open H+ chanels -> actively pump protons into thylakoid space against conc gradient.
- The e- from ETC are captured by chlorophyll in PSI (p700) to replace those lost by light excitation
- The e- enter another ETC moving them into stoma
- As protons accumulate in thylakoid space, an electrochemical gradient is generated across membrane
- Protons diffuse down gradient through ATP-synthase channels (co-enzyme)
- Proton flow causes ADP + Pi in stroma to photophosphorylate into ATP
- An e- (from carrier chain) + proton (from ATP synthase channel) combine with NADP (co-enzyme) to make NADPH (reduced NADP) is catalysed by NADP reductase.
Explain the Electron Transport Chain:
