Photosynthesis is the process whereby light energy from the sun is transformed into chemical
energy and used to make large molecules from inorganic substances from inorganic substances
. it Also releases oxygen into the atmosphere . The energy is also stored in thr form of sugar
which are created from water and carbon dioxide.
Photosynthesis occurs in some bacteria and plant cells . The plants cells contain organelles
called chloroplasts where photosynthesis take place
Chloroplasts vary in shape and size .
They are 2-10 um long
They are surrounded by double membrane
Contain a stack of sacs ( thylakoids ) which hold pigment called chlorophyll .
The outer membrane is permeable to small ions .But the inner membrane is less permeable
because it contains transport proteins which helps with controlling the entry and the exit of
molecules . There is an intermembrane space between the double membrane of about 10-2-
nm .The floods in the inner membrane are called lamellae . The lamellae are stacked up
Photosynthesis takes place in chloroplasts. The equation for photosynthesis is
6H 0 + 6CO -> C H O + 6O , water + Carbon Dioxide -> Glucose + Oxygen.
2 2 6 12 6 2
The chloroplasts contain two regions: the grana and the stroma.
• Grana is like piles of dishes. Each individual membrane-bound sac (lamina) is called a
thylakoid. This is where light is absorbed and ATP is synthesized during the light-dependent
reaction.
• The stroma is a fluid-filled matrix in which the enzymes required for the light-independent
phase are located. They also contain starch granules, oil, DNA and ribosomes.
The thylakoid membranes within the granules provide ample space for photosynthetic pigments,
electron carriers, and ATP synthase enzymes. Note that it is necessary for the light-dependent
reaction. Photosynthesis pigments are arranged in special structures called photosystems.
, This is to allow the absorption of the largest possible solar energy. Grana contains proteins
held in place.
The photosynthetic pigments, electron transporters, and ATP synthase enzymes all require a
high surface area in the light-dependent stage, which is provided by the grana's thylakoid
membranes.
Photosystems are made up of pigments that are organised in a certain way. The thylakoid
membrane has funnel-shaped structures that are kept in place by proteins
Chlorophyll is the green pigment present in plants, however it is made up of other pigments,
including P680, P700, and carotenoids. P680 and P700 are yellow/green pigments, however
they absorb red light at different wavelengths.
Photosynthesis can be divided into two steps
The light dependent stage
The light independent stage
The light-dependent stage
The phase of light-dependent photosynthesis occurs on the thylakoid membrane of the
chloroplast. Photosystems containing photosynthetic pigments are embedded in this
membrane.
The photolysis system Il
contains that enzyme that can split water into protons (H ions), electrons and oxygen When
(photolysis) some oxygen is used in the plant for aerobic respiration, but most of it diffuses out
of the leaf through the stomata Hions are used during chemiosmosis to produce A proton
gradient to produce ATP, it is used to reduce a common enzyme called NADP used in the light-
independent phase. Finally, the electrons are used to replace those lost by chlorophyll. :
energy and used to make large molecules from inorganic substances from inorganic substances
. it Also releases oxygen into the atmosphere . The energy is also stored in thr form of sugar
which are created from water and carbon dioxide.
Photosynthesis occurs in some bacteria and plant cells . The plants cells contain organelles
called chloroplasts where photosynthesis take place
Chloroplasts vary in shape and size .
They are 2-10 um long
They are surrounded by double membrane
Contain a stack of sacs ( thylakoids ) which hold pigment called chlorophyll .
The outer membrane is permeable to small ions .But the inner membrane is less permeable
because it contains transport proteins which helps with controlling the entry and the exit of
molecules . There is an intermembrane space between the double membrane of about 10-2-
nm .The floods in the inner membrane are called lamellae . The lamellae are stacked up
Photosynthesis takes place in chloroplasts. The equation for photosynthesis is
6H 0 + 6CO -> C H O + 6O , water + Carbon Dioxide -> Glucose + Oxygen.
2 2 6 12 6 2
The chloroplasts contain two regions: the grana and the stroma.
• Grana is like piles of dishes. Each individual membrane-bound sac (lamina) is called a
thylakoid. This is where light is absorbed and ATP is synthesized during the light-dependent
reaction.
• The stroma is a fluid-filled matrix in which the enzymes required for the light-independent
phase are located. They also contain starch granules, oil, DNA and ribosomes.
The thylakoid membranes within the granules provide ample space for photosynthetic pigments,
electron carriers, and ATP synthase enzymes. Note that it is necessary for the light-dependent
reaction. Photosynthesis pigments are arranged in special structures called photosystems.
, This is to allow the absorption of the largest possible solar energy. Grana contains proteins
held in place.
The photosynthetic pigments, electron transporters, and ATP synthase enzymes all require a
high surface area in the light-dependent stage, which is provided by the grana's thylakoid
membranes.
Photosystems are made up of pigments that are organised in a certain way. The thylakoid
membrane has funnel-shaped structures that are kept in place by proteins
Chlorophyll is the green pigment present in plants, however it is made up of other pigments,
including P680, P700, and carotenoids. P680 and P700 are yellow/green pigments, however
they absorb red light at different wavelengths.
Photosynthesis can be divided into two steps
The light dependent stage
The light independent stage
The light-dependent stage
The phase of light-dependent photosynthesis occurs on the thylakoid membrane of the
chloroplast. Photosystems containing photosynthetic pigments are embedded in this
membrane.
The photolysis system Il
contains that enzyme that can split water into protons (H ions), electrons and oxygen When
(photolysis) some oxygen is used in the plant for aerobic respiration, but most of it diffuses out
of the leaf through the stomata Hions are used during chemiosmosis to produce A proton
gradient to produce ATP, it is used to reduce a common enzyme called NADP used in the light-
independent phase. Finally, the electrons are used to replace those lost by chlorophyll. :
