Ib HL Biology: Photosynthesis -C1.3

The two types of chlorophyll

Chlorophyll alpha and beta

Paper chromatography

• technique used to separate mixtures of substances

• Used the mobile phase and stationary phase for the separation process

• Paper: stationary phase

• Solvent used to develop chronograph: mobile phase

• Solvent is often made out of alcohol

photolysis

• the breaking down of water into hydrogen ions, oxygen and electrons using light energy

• occurs in grana

• so that the hydrogen ions can be used for atp synthesis and so that the electrons can be used in photosystem 2

Main types of pigments in plants

Chlorophyll’s, beta caroten, xanthophyll

Retention factor/ Rf

Spdistance travelled by sample / distance travelled by solvent

Graph which represents wavelengths of light absorbed

Absorption spectrum

Graph which shows rate of photosynthesis against wavelength

Action spectrum

Rage of wavelength which make up visible light

400-750nm

Limiting factors in rate of photosynthesis

• light intensity

• Température

• CO2 concentration

FACE

Free air carbon dioxide enrichment experiments; CO2 is released in a circular area and sensors are used to detect concentration and keep it high

Photosystems

arrays of pigment molecules which can generate excited electrons. found in thylakoid membranes of grana

chemiosmosis

osmosis but with chemicals. in photosynthesis ATP is produced by this process using ATP synthase, by allowing hydrogen ions to leave the thylakoids by facilitated diffusion

photosphorylation

The process of generating ATP using light energy. It occurs during the light-dependent reactions of photosynthesis, in photosystem 1, where light energy is used to phosphorylate ADP to ATP.

electron transport chain ( ETC )

A series of protein complexes in the inner membrane of the mitochondria that transfer electrons and pump protons to create a proton gradient.

basically the photosystems + electron storers

cytochrome complex

• the hydrogen pump

• excited electron pases, it’s energy is used to bring the hydrogen ions from a low to a high concentration

• the electron goes back to the ground state

difference between absorption spectrum

• action spectrum: rate of photosynthesis for each wavelength

• absorption spectrum: what wavelengths are getting absorbed

How much energy required to synthesise one mole of glucose

2017Kj

Chemoautotrophs

Source of energy from chemicals

what is in photosystem 2

• a water splitting enzyme that catalyses the breakdown of water

• oxygen is a waste product of the reaction

• electrons are used for the electron chain, hydrogen ions are used for the ATP synthase

fixation of CO2

• using rubisco, a CO2 molecule is put in a RuBp molecules and they become two GP molecule ( glycerate-3-phospate)

where is NADPH used in the Calvin cycle

• when glycerate- 3- phosphate ( GP ) is present with NADPH and ATP, it becomes triose phosphate ( TP )

non-cyclic phosphorylation

• normal one

• occurs when water is present to photolyse and produce electrons

• use NADP+

cyclic phosphorylation

• occurs when not enough water is present

• no NADP+

• electrons go back in ground state in photosystem 1

RuBp full name

ribulose bisphophate, a 5 carbon molecule which reacts with CO2 in Atmosphere

G-3-P full name

glycerol - 3 - phosphate, product of breakdown of unstable intermediate after carbon fixation

TP

triose phosphate, produced from GP, after using NADH and 2 ATP

calvin experiments

• radioactive labelling ( label CO2 with carbon 14 )

• double way paper chromatography

• autoradiography

autoradiography