U2T2 - Keywords

Question 1

Photosynthesis

Answer 1

Conversion of sunlight energy into chem energy in form of complex carbohydrates. Transduction. Occurs in chloroplasts.

Question 2

Transduction

Answer 2

Conversion of 1 form of energy into another.

Question 3

Photon

Answer 3

Package of light energy.

Question 4

Light Harvesting

Answer 4

Process of absorbing light in photosystems attached to thylakoid membranes of chloroplast. Raises energy levels of electrons in chlorophyll. Most red + blue light absorbed. Primary pigment emits electron to electron acceptor.

Question 5

Photosystem

Answer 5

2 types. Composed of hundreds of pigment molecules like chlorophyll. Contains primary pigment and accessory pigments.

Question 6

Primary Pigment

Answer 6

In photosystem. 1 molecule that acts as reaction centre.

Question 7

Accessory pigments

Answer 7

Molecules in photosystem which funnel light photons onto primary pigment.

Question 8

Antenna Complex

Answer 8

All accessory pigments together. Harvests light over range of diff wavelengths. As light passes through, special proteins pass absorbed energy by resonance transfer towards reaction centre. Molecules must be part of regular arranged structure.

Question 9

Photosystem 1

Answer 9

Contains primary pigment P700 which absorbs light wavelength of 700nm.

Question 10

Photosystem 2

Answer 10

Contains primary pigment P680 which absorbs light wavelength of 680nm.

Question 11

Photoactivation

Answer 11

Light energy used to excite electrons within primary pigment to higher energy level.

Question 12

Chlorophyll

Answer 12

Combo of diff pigments (chlorophyll a + b, carotenoids)Chlorophyll has ring like structure, Mg centre joined to hydrophobic hydrocarbon tail, anchoring in thylakoid. Carotenoids include xanthophylls + carotenes (yellow/orange, red/brown) Accessory pigments, absorb light of diff wavelengths + pass energy onto chlorophyll to assist in photoactivation.

Question 13

Action Spectra

Answer 13

Graph of rate of photosynthesis vs wavelength. Rate dependent on wavelength.

Question 14

Absorption Spectra

Answer 14

Graph of absorption vs wavelength.

Question 15

Light Independent Stage

Answer 15

Occurs within stroma. To fix CO2 into organic compounds. ATP + NADPH from light dependent stage required, Calvin Cycle shows intermediate molecules.

Question 16

RuBP

Answer 16

Ribulose 1,5 Bisphosphate. CO2 acceptor.

Question 17

RUBISCO

Answer 17

Ribulose Bisphosphate Carboxylase Oxygenase. Most abundant enzyme on earth. Catalyses CO2 + RuBP.

Question 18

GP

Answer 18

Glycerate 3 phosphate. GP/PG/Phosphoglyceric acid.

Question 19

Compensation Point

Answer 19

When light intensity is such that photosynthesis and respiration are at equal rate and CO2 absorbed vs released is the same (or O2)

Question 20

Gross Photosynthesis

Answer 20

Total amount of photosynthesis occurring. Measured by amount of O2 or carb produced. Some products used by plant in resp, leading to net.

Question 21

Net Photosynthesis

Answer 21

Gross photosynthesis - resp demands of plant.
Total photosynthesis minus products used in resp.
At compensation point, this is 0.

Question 22

Chloroplast

Answer 22

Large organelle with thylakoids containing chlorophyll to absorb light.

Question 23

Thylakoids

Answer 23

Flattened membranes in chloroplast. Contain systems of electron carriers + associated enzymes. Arranged in stacks called grana. Linked by intergranal lamellae.

Question 24

Non-cyclic photophosphorylation

Answer 24

Production of ATP in photosynthesis.

Question 25

Palisade layer

Answer 25

A layer of parallel elongated cells below the epidermis of a leaf which contain lots of chloroplasts and chlorophyll for photosynthesis.

Question 26

Chlorophyll

Answer 26

A green pigment which is responsible for the absorption of light to provide energy for photosynthesis.

Question 27

Electron carrier

Answer 27

Any of various molecules that are capable of accepting one or two electrons from one molecule and donating them to another in the process of electron transport. As the electrons are transferred from one carrier to another, their energy level decreases, and energy is released.

Question 28

Limiting factor

Answer 28

Variable of a system that, if subject to a small change, causes a non-negligible change in an output or other measure of the system.

Question 29

Light dependent stage

Answer 29

The series of biochemical reactions in photosynthesis that require light energy that is captured by light-absorbing pigments (such as chlorophyll) to be converted into chemical energy in the form of ATP and NADPH. Occurs in thylakoid membranes in chloroplast. Water is dissociated and it’s H2 ions reduce NADP.

Question 30

Reaction centre

Answer 30

A complex of several proteins, pigments and other co-factors that together execute the primary energy conversion reactions of photosynthesis.

Question 31

Resonance transfer

Answer 31

Transfer of energy from one fluorochrome to another. The emission wavelength of the fluorochrome excited by the incident light must approximately match the excitation wavelength of the second fluorochrome. Energy is funnelled to the reaction centre of a photosystem using this method.

Question 32

Photophosphorylation

Answer 32

The synthesis of ATP from ADP and phosphate that occurs in a plant using radiant energy absorbed during photosynthesis.

Question 33

Photolysis

Answer 33

The decomposition or separation of molecules by the action of light.

Question 34

NADP

Answer 34

Nicotinamide adenine dinucleotide phosphate. A coenzyme that occurs in many living cells and functions as an electron acceptor like NAD but reacts with different metabolites. Has an extra phosphate group.

Question 35

Photoactivation

Answer 35

The process of activating a substance by means of radiant energy and especially light.

Question 36

Stroma

Answer 36

The matrix of a chloroplast, in which the grana are embedded.