3.1 - Food supply, plant growth and productivity Flashcards
define Food security
the ability of human populations to access food of sufficient quality and quantity
Food production must be…
sustainable and
not degrade the natural resources
how is crop production efficiency improved
- Using fertilisers
- Breeding higher yielding cultivars
- Protecting crops from pests, diseases and competition
name desired crop qualities
- High nutritional values
- Resistance to pests and diseases
- Physical characteristics suited to rearing and harvesting
- Thriving in particular environments
pro and con of livestock production
- Produce less food per unit area due to loss of energy between trophic levels
- However, production often possible in land unsuitable for crops
light energy is absorbed by (general term)
photosynthetic pigments
what do photosynthetic pigments generate atp for
photolysis
what are the 3 fates of light energy
absorbed transmitted reflected
what does the absorption spectrum show
the wavelengths of light absorbed by different pigments in a leaf
what does the action spectrum show
the efficiency of different wavelengths of light are at photosynthesis
what is the role of caretenoids
to extend the range of wavelengths absorbed and to pass the energy to chlorophyll for photosynthesis
what is unique about each pigment
they absorb a different range of wavelengths of light
what does light energy do to pigment molecules
excites their electrons
these electrons create…
atp by atp synthase through the electron transport chain
what is the energy also used for
photolysis
what is photolysis
water is split into oxygen, which is evolved, and hydrogen which is transferred to the coenzyme nadp
syn for the carbon fixation phase
calvin cycle
what does evolved mean
released (o2 into atmosphere)
what does phosphorylate mean
add a phosphate group
what is the long form RuBP
ribulose biphosphate
what is the long form of 3PG
3-phosphoglycerate
what is the long form of G3P
glyceraldehyde-3-phosphate
carbon fixation stage: … + … ___> …
RuBP + CO2 -RuBisCO> 3PG
reduction stage: … + … +… > … + … + …
3PG + ATP + NADPH > G3P + ADP + NADP
What is G3P used for
regeneration of RuBP and synthesis of glucose
Glucose uses :
respiratory substrate, synthesised into starch or cellulose or passed to other biosynthetic pathways.
what can these biosynthetic pathways lead to
the formation of a variety of metabolites such as DNA, protein and fat.
