photosynthesis☀️🪴 Flashcards
how are grana adapted for their function
- contain ETC/ ATP synthase
- large SA for light absorption
where in chloroplast is the metabolic pathway involving co2
stroma
why is the theoretical rate of photosynthesis not achieved as light intensity increases
- temperature is a limiting factor as the calvin cycle relies on enzymes
- co2 is a limiting factor as it is required for calvin cycle
how are plants adapted to live in shade
- more chloroplasts
- more grana
- larger leaf SA
how are heterotrophs reliant on plants
- heterotrophs have to eat plants for glucose
- autotrophs produce glucose and oxygen by photoaynthesis
- heterotrophs need oxygen for respiration
name an accessory pigment
- carotene
- chlorophyll b
what is the first stable product of carbon dioxide fixation
glycerate 3 phosphate
what is the compound regenerated in the calvin cycle so more co2 can be fixed
RuBP
name a compound that can be formed from TP but not as a part of the calvin cycle
amino acid
what is an autotroph
can make organic molecules from inorganic molecules
what is a heterotroph
relies on organic molecules produced by another organism
what are fat droplets in the chloroplast for
- membrane formation
- fatty acid synthesis
how is light harvested in chloroplast membranes
- pigments form antenna complex
- photon absorbed by pigment
- electron excited and returned to pigment
- photon passed from one pigment to another
- photon passed to reaction centre
- range of accessory pigments allow range of wavelengths to be absorbed
effect of blocking movement of electrons between electron carriers on photosynthesis
- prevents non cyclic photophosphorylation
- no electrons available to form NADPH
- less ATP and NADP for calvin cycle
problems with using o2 production/ co2 uptake to measure photosynthesis rate
- oxygen only produced in one stage
- oxygen produced may be used for respiration
- carbon dioxide only used in one stage
- carbon dioxide uptaken may be used for photosynthesis
how does a chemical that binds to electrons in photosystem i lead to death of plant
- prevents cyclic and non cyclic photophosphorylation
- less NADPH for calvin cycle
- no glucose made for respiration
final electron acceptor in light dependent stage of photosynthesis
NADP
how many carbons does RuBP contain
5
what does rubisco do
converts RuBP to 6 carbon compound
when is CO2 used in the calvin cycle
-one CO2 fixed to RuBP to form 6C compound
when is ATP used in the calvin cycle
- 2 ATP used to convert 2GP into 2TP
- 1ATP used to convert 2 TP into RuBP
when is NADPH used in the calvin cycle
2 NADPH used to convert 2GP to 2TP
where is PSII located
beginning of ETC
where is PSI located
middle of ETC
which photosystem(s) does cyclic photophosphorylation use
PSI only
describe cyclic photophosphorylation
- light absorbed by PSI and passed onto pigment
- electron in pigment is excited to higher energy level
- electron goes down ETC and then back to PSI
- this provides energy for proton pump
- ATP produced by chemiosmosis
describe non cyclic photophosphorylation
- light absorbed by PSII and passed to pigment
- electrons excited to higher energy level then ETC
- electrons passed to PSI
- ATP produced by chemiosmosis
- photolysis, electrons from water go to PSII
- electrons from PSI go to ETC
- electrons combine with H+ and NADP to form NADPH
where is photolysis
- PSII
- thylakoid lumen
products of photolysis
- proton
- electron
- oxygen
where are protons pumped from and to in the light dependent stage
from stroma to thylakoid lumen
when is NADPH produced
during non cyclic photophosphorylation
